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LONG-TERM OF AMERICAN SIGN IN A

CHIMPANZEE (PAN TROGLODYTES)

______

A Thesis

Presented to the

Faculty of

San Diego State University

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In Partial Fulfillment

of the Requirements for the Degree

Master of Science

in

Interdisciplinary Studies

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by

Summer Lee Brooks

Spring 2012

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Copyright © 2012 by Summer Lee Brooks All Rights Reserved

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DEDICATION

Dedicated to Booee, the chimp who would “sell his soul for a raisin.” Knowing him has been a true honor that I will never forget. I will especially treasure the of his obsession with playing chase until I was exhausted, and his very mannerly laugh where he covers his teeth with his lips. He doesn’t know it, but he made my dreams come true. When I was five years old, I read Patterson’s (1985) book “’s Kitten.” To a five year old, it made perfect sense that a could converse with humans in (ASL), and care for an orphaned kitten. How little did anyone know that “Koko’s Kitten” would direct the course of my life! From that moment I wanted to be like Penny Patterson, and talk to apes in sign language. My interests in ASL, and the ape language studies can all find their roots in “Koko’s Kitten.” As I grew academically and professionally, my interest always came back to the ape language studies and my fascination with the notion that humans can converse with . By the time I was in college, I had read Fouts’ (1997) book “,” and was amazed that the ability to talk with animals extended beyond Koko the gorilla. Fouts’ book is where I learned about Booee and the other ASL . When I found that Booee was residing only a few hours away, I knew I had to meet him… the chance of a lifetime! I was chosen for a behavior and enrichment internship at the sanctuary where he resides, and Booee and I became great friends. Having the opportunity to interact with a signing ape has been a culmination of all my lifelong interests. And I am so privileged that Booee was the ape I came to know. He is the sweetest, silliest and most charming I have had the pleasure to meet. I am forever indebted to him, not only because he agreed to participate in my long-term memory study, but because he made my life-long dream come true. Booee died December 10, 2011, five days before final submittal of this thesis.

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ABSTRACT OF THE THESIS

Long-Term Memory of American Sign Language in a Chimpanzee (Pan troglodytes) by Summer Lee Brooks Master of Science in Interdisciplinary Studies San Diego State University, 2012

For hundreds of years, humans have dismissed the possibility that animals possess long-term memory capabilities. This study examines the long-term memory of American Sign Language (ASL) by a chimpanzee (Pan troglodytes). The study of long-term memory in apes may help evolutionary psychologists to understand how humans have evolved to have cognitive abilities that are unequaled by other species. Booee, the participant in this study, was involved in the ape language experiments of the 1970s. His study concluded in 1982, and since that time he has not regularly conversed in ASL. In the current study, Booee was presented with five items from his former ASL vocabulary list. When asked for an item in ASL, he was expected to point to the item. Items were presented in groups of four. The hypothesis of this study was that Booee would point to the correct item at significantly above the chance level of 25%. As a control measure, he was also presented with five items for which he had never learned the signs. When asked to point to these items (also in groups of four), it was expected that he would answer correctly at chance. This might demonstrate that he remembered the ‘old’ signs, and possesses long-term memory capabilities. Data analysis showed that his correct answers for both "old" and "new" signs were consistently at chance level. Although the data did not support the hypothesis, informal observations of Booee's sign production may demonstrate that he does possess long-term memory of ASL. Long-term memory research in animals is scarce. It has only been in the last 15 years that serious progress has been achieved. Adding to the scientific literature on long-term memory in animals will encourage other researchers to examine this phenomenon, and will help evolutionary psychologists to better understand the memory capabilities of our closest relatives, and ourselves.

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TABLE OF CONTENTS

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ABSTRACT ...... v LIST OF TABLES ...... viii LIST OF FIGURES ...... ix ACKNOWLEDGEMENTS ...... x CHAPTER 1 INTRODUCTION ...... 1 2 LITERATURE REVIEW ...... 4 Definition of Memory ...... 4 Long-Term Memory ...... 4 Summary ...... 5 The Evolution of Memory ...... 6 Animal Memory ...... 7 Animal Long-Term Memory Studies...... 8 Ape Language Research ...... 10 ...... 11 Fouts’ Ape ASL Studies ...... 13 Booee ...... 16 3 METHODS ...... 22 Participants ...... 22 Study Site ...... 23 Research Design...... 24 Preparation ...... 25 Apparatus ...... 25 Training ...... 26 Change in Research Design Based on Training Trials ...... 27 Data Collection ...... 28 Pilot Study ...... 28

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Experimental Data Collection ...... 29 4 RESULTS ...... 31 5 DISCUSSION ...... 36 Conclusion and Recommendations ...... 37 Ethical Considerations ...... 38 REFERENCES ...... 42 APPENDIX A BOOEE’S SIGN VOCABULARY...... 47 B DESCRIPTIONS OF “OLD” AND “NEW” SIGNS...... 49 C EXAMPLE OF DATA SHEET ...... 51

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LIST OF TABLES

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Table 1. “Old” Signs: Times Asked, Times Correct and Total Answers ...... 32 Table 2. “New” Signs: Times Asked, Times Correct and Total Answers ...... 33 Table 3. All Signs: Times Asked, Times Correct and Total Answers ...... 34

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LIST OF FIGURES

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Figure 1. Cage configuration...... 23 Figure 2. Apparatus...... 26

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ACKNOWLEDGEMENTS

Special thanks to: My parents, without whose love, support and guidance I could never have achieved many of my accomplishments in life. My aunts Helen, Anne and Donna, who are my constant cheerleaders. My grandfather, Justiniano Baca, who always remembers to share an interesting animal anecdote with me. Nicholas Dodman, BVMS, who took my interest in animal behavior seriously, even when I was only fourteen years old. Lissa Ongman, who first taught me about chimpanzee behavior and husbandry, and whose courage constantly inspires me. Dr. Al Hillix, who agreed to chair my thesis committee and be my mentor. Without him this study would not have been possible. “Leakey’s Angels”: , and Birute Galdikas, whose work encourages aspiring female scientists everywhere. Also: Dr. Erin Riley, Dr. Rulon Clark, Dr. Dena Plemmons, Dr. Duane Rumbaugh, Dr. Kevin Scoggin, Dr. Lorri Greene, Dr. William Clary, Dr. , Dr. , Dr. Lyn Miles, Grand Animal Hospital, the Waystation, Charlie and Phyllis Baca, the Brooks family in Georgia, and all the great apes who have participated in the ape language experiments.

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CHAPTER 1

INTRODUCTION

Comparative and evolutionary psychologists study the cognitive capabilities of animals in order to understand the evolution of human cognition. Discovering how and why an animal’s brain functions in certain ways leads to greater understanding of the origins of human cognitive abilities. For instance, in the human brain, Broca’s area is responsible for speech production. Scientists recently discovered that the analogous part of the brain in the macaque is responsible for the control of facial muscles (Petrides, Cadoret & Mackey, 2005). This led researchers to hypothesize that Broca’s area in humans evolved to create the facial and oral movements necessary for speech (Moore, 2001). One area of interest for comparative study is the capacity for memory in non-human animals. Evolutionary theorists are particularly interested in the memory capabilities of apes because of their recent evolutionary divergence from humans. Studying memory in non- human will not only enlighten the scientific community about cognitive abilities of animals, but also provide insight into the evolutionary roots of human memory. Scientists can only speculate about the cognitive and environmental demands that our hominid ancestors faced. However, we can study the non-human primates from which humans most recently diverged. Great apes (chimpanzees, , and ) share 95- 98% of human DNA (Maestripieri & Roney, 2006). Because of this genetic similarity, they also share many physiological, psychological, behavioral and morphological traits with humans (Maestripieri & Roney, 2006). Great apes are the scientific community’s best way to study how human ancestors may have interacted with the environment. Although humans presently live in a drastically different environment from that faced by apes, ancient hunter- gatherers most likely faced social and ecological problems similar to those that apes currently face (Hauser, 2005). Evolutionary psychologists act under the assumption that organisms evolve, through natural selection, by adapting to their environments (Bjorklund & Pellegrini, 2000). Changes resulted from our ancestors solving problems in their environment, which made them more

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fit to survive and reproduce (Bjorklund & Pellegrini, 2000). Our vast human memory capabilities must have arisen from our ancestors’ adaptations to their environment, which enhanced their survival and reproductive fitness. The ways in which apes adapt to their environment may exemplify conditions that caused the hominid brain to develop the memory capabilities we have today. Humans have three memory processes: sensory memory, short-term memory and long-term memory. Sensory memory is the ’s way of processing information experienced by the senses, and deciding which information it will attend to. When focusing on the information, it resides in short-term memory (Atkinson & Shiffrin, 1968). If this information is rehearsed, it will transfer to the mind’s vast long-term memory store (Atkinson & Shiffrin, 1968). Once the information transfers to long-term memory, it can be retrieved at will (Tulving, 1972; but see the later discussion of factors affecting retrieval). At the beginning of the 20th century, the works of Pavlov (1927) and Watson (1913) convinced the research community that animals could learn only by . Studies of cognition in animals only began in earnest by the second half of the century, and studies of memory tended to focus on short-term memory tasks. Experimental research on long-term memory in animals began only recently. Scientists have studied birds (Clayton & Dickinson, 1998) and apes (Beran, Pate, Richardson & Rumbaugh, 2000; Menzel, 1999) to understand whether they possess types of long-term memory previously to be uniquely human (Tulving, 1972). The ape studies used language-trained chimpanzees. In the late 1960s through the 1970s, “ape ” dominated animal cognition research. Researchers from varying scientific disciplines attempted to communicate with apes through the use of American Sign Language (ASL) (Fouts, 1973; Gardner & Gardner, 1969), tokens (Premack & Premack, 1972) or symbols (Rumbaugh, 1977). The ability to exchange ideas with apes through the use of language expanded the possibilities of examining the cognitive capabilities of animals. The ability to converse with them provided a way to ask them what they thought or what they understood about the world. Prior to this line of research, the only way to study animal cognition was through observable behaviors. The present study investigated one chimpanzee’s (Pan troglodytes) ability to remember signs in ASL that he had not used in over 27 years. Demonstrating that a

3 chimpanzee is able to recall gestures he learned decades previously would help to establish that animals do possess the capabilities necessary for long-term memory. Booee, the single-subject participant in the present study, was 41 years old when the study began. He was home-reared by humans for the first 30 months of life, and then transferred in 1970 to the Institute for Primate Studies (IPS) at the University of Oklahoma (Fouts, 1997). He participated in many ASL acquisition studies at IPS, and learned over 40 signs (Fouts, 1997; Miles, 1978). In 1980, he was transferred to a biomedical facility, where he was a subject in Hepatitis B and C research (Linden, 1986). In 1995, he was retired to an exotic animal sanctuary in Los Angeles, CA, where he currently resides. In the present study, Booee was presented with five items from his former ASL vocabulary list. Items were presented to him in groups of four, and when asked “WHERE [item]?” in ASL, he was supposed to point to the correct item. The hypothesis of this study was that Booee would point to the correct item at significantly above chance levels. As a control measure, he was also presented with five items for which he never learned the signs. When asked to point to these items (also in groups of four), it was expected that he would answer correctly at chance levels (25%). This would demonstrate that he remembers the ‘old’ signs, and possesses long-term memory capabilities. It was also hypothesized that Booee would improve his performance as the study progressed. This study will add to other recent findings (Beran et al., 2000; Menzel,1999) on ape long-term memory.

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CHAPTER 2

LITERATURE REVIEW

DEFINITION OF MEMORY In humans, there are three memory processes: sensory, short-term and long-term (Atkinson & Shiffrin, 1968). Each of these processes can be broken down into multiple components. Sensory memory receives information from the environment, such as what one sees or hears. Retention of sensory memory lasts for mere seconds (Atkinson & Shiffrin, 1968). Sensory memory chooses what information the brain will attend to. Once is brought to this information, it may transfer to short-term memory (STM). Short-term memory can focus on small amounts of information, and can process it for approximately one minute (Atkinson & Shiffrin, 1968). If this information is rehearsed, it may transfer into long-term memory. If it is not rehearsed, it may “decay” and be lost (Atkinson & Shiffrin, 1968, p. 19). Long-term memory systems store a vast array of information over long periods of time (Baddeley, Eysenck, & Anderson, 2009). Long-term memory is sometimes even referred to as “permanent storage” (Atkinson & Shiffrin, 1968). Although memory has been scientifically investigated since the late 1800s (Ebbinghaus, 1913) it is still not thoroughly understood (Baddeley et al., 2009). There are many complementary theories as to how the brain processes and accesses memories (Baddeley & Hitch, 1974; Broadbent, 1958; Squire, Knowlton & Musen, 1993; Tulving, 1972). The present study focuses on long-term memory.

LONG-TERM MEMORY Long-term memory is divided into two components: explicit and implicit memory (McDougall, 1923). Explicit memory is also called declarative memory because of one’s ability to state the information therein verbally. Explicit memory is concerned with remembering events and recalling facts (Baddeley et al., 2009). Implicit memory is non- declarative, in that has occurred but it is not easily describable. This component of memory is demonstrated by performance of a learned motor behavior such as riding a bike (Baddeley et al., 2009).

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Explicit memory is separated into two systems: episodic memory and semantic memory (Tulving, 1972). Episodic memory is a record of a person’s past experiences. These memories have autobiographical components concerned with who, what, where and when. Semantic memory is the vast array of an individual has about the world (Tulving, 1972). The difference between the systems can be described as the difference between remembering (episodic memory) and knowing (semantic memory) (Tulving, 1985). It is thought that episodic memory evolved out of semantic memory (Tulving, 1993). Semantic memory can store information independently of the episodic system, but not visa versa. Episodic memory needs the factual referents in order to place itself in time. This is evidenced in children’s ability to learn facts and general knowledge before being able to remember their own personal experiences (Tulving, 1993). Episodic memory is one’s ability to consciously re-live one’s past experiences (Tulving, 2002). It is what enables a person to be consciously aware of an earlier event in his or her own personal history (Tulving, 1993). According to Tulving (1993), episodic memory can be described as the ability for “mental time travel,” namely the ability to “transport at will into the personal past, as well as into the future” (p. 67). This includes the conscious of re-experiencing the event, called “autonoetic ” (Tulving, 1993). Semantic memory is a system that allows for storage of facts, , quantities and objects (Tulving, 1972). This type of memory differs from episodic memory because it does not refer to the events one has experienced or the emotions that correspond to them. It is the ability to mentally recall objects and relations in the world that are not currently present (Tulving, 1993). Semantic memory is the vast storage system that allows an organism to remember thousands of bits of information and recall it at a later date when needed. Tulving (1972) states that semantic memory is necessary for language, because it stores knowledge about words and verbal symbols. It is a “mental thesaurus” (Tulving, 1972, p. 386). Many of the facts stored in semantic memory remain stored indefinitely.

SUMMARY The three systems of memory are sensory, short-term and long-term. Sensory memory aids in processing information received form the environment. Short-term memory stores information that is perceived, and if it is concentrated on, it may transfer into long-

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term memory. Long-term memory has two components- explicit and implicit memory. Explicit memory deals with facts and knowledge about the world, while implicit memory deals with behavior performance, such as riding a bike. Within explicit memory, there are two types of memory that deal with facts about the world. Episodic memory is autobiographical, in that it deals with remembering one’s personal past experiences. Semantic memory is a “mental thesaurus” that allows for remembering vast numbers of facts about the world.

THE EVOLUTION OF MEMORY Although researchers have defined the processes of memory, there is very little mention of the evolution of memory (Nairne and Pandeirada, 2008). If memory evolved, it would have followed Darwin’s (1859) rules of evolutionary change by natural selection. Natural selection occurs via three steps: (1) only a small percentage of each generation survives to reproduce, (2) each individual is slightly different from other individuals (i.e. there is variation) and (3) one or more components of this variation make it more likely that certain individuals will survive and reproduce. Selection for a particular trait depends on the environmental demands that individual must face. This trait may give that individual an advantage in the environment that others do not have, so it will survive to reproduce, and pass on that trait to future generations. Memory allows organisms to act based on information they acquired from previous experiences (Klein, Cosmides, Tooby & Chance, 2002; Tulving, 1995). Memory likely evolved to help organisms make decisions based on these prior experiences (Klein et al., 2002). Memory began with sensory perception. All animals can perceive input from their environment (Goodson, 2003). Basic memory and learning by conditioning came next. The short-term ability to learn from sensory input and act upon it in the future meant that organisms were no longer dependent on inherited mechanisms and fixed-action patterns (Goodson, 2003). Organisms could make adaptive responses to novel situations. It is thought that the evolution of the hippocampal region of the brain is responsible for enhanced short-term memory abilities in (Squire, 1992). The is also integral for the processing, storage and transfer of declarative (long-term) memories (Squire, 1992).

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The evolution of long-term semantic and episodic memory is not easily defined. It is believed that (temporary retention of spatial location) evolved to have long- term semantic properties (Schwartz & Evans, 2001) and semantic memory processes may have adapted from there. Semantic memory allowed organisms to remember an almost infinite number of facts about the world (Tulving, 2002). These organisms could then act upon learned behaviors (Goodson, 2003), understand territory boundaries, remember sites, and build social groups (Sherry & Schacter, 1987). Episodic memory is thought to have evolved as “an embellishment” to semantic memory (Tulving, 2002). As semantic memory can exist without episodic references, but not visa versa, this may prove that episodic is dependent on semantic memory in order to exist. Semantic memory is considered the foundation for episodic memory (Tulving, 1984). According to Schwartz and Evans (2001), the evolution of episodic memory would have aided primates and ancient hominids in foraging behavior. While remembering where fruitful trees are located would be considered spatial semantic memory, remembering specific visits to a particular tree would be considered episodic memory. Remembering this visit and deciding not to visit a tree that was recently depleted of fruit would save time and energy for the forager. Schwartz and Evans (2001) also mention that the building of social relationships may rely on episodic memory. Remembering “friends or foes” (p. 82) may have helped primates and hominids in anticipating future social interactions. Memory for specific past events with conspecifics may have helped them plan for future cooperation (Schwartz & Evans, 2001). There is much discussion about the existence of episodic memory in animals, especially in great apes (Clayton & Dickinson, 1998; Clayton, Bussey & Dickinson, 2003; Menzel, 1999; Suddendorf & Corballis, 1997; Terrace & Metcalfe, 2005; Tulving, 2002). Demonstrating the existence of short-term and semantic memory in animals may advance this debate.

ANIMAL MEMORY Humans have pondered the memory capabilities of animals since the times of the great philosophers. (384-322 BC) proclaimed that “no other animal except man can recall the past at will” (as cited by Winograd, 1971, p. 259). Rene Descartes (1596-1650 CE)

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likened animals to machines, stating that they did not think, nor did they have any types of cognitive abilities (Descartes, 2006). Scientists have accepted these philosophical opinions for hundreds of years, denying that animals possess cognition of any kind. However, in the 1920s, primatologists Köhler (1925) and Yerkes & Yerkes (1928) began to believe that apes (specifically chimpanzees) have more abilities than generally acknowledged. Köhler (1925) remarked that the apes he studied seemed to recognize him even after a long absence. Yerkes & Yerkes (1928) demonstrated that chimpanzees could remember the location of hidden objects after extended delays. Although these and other scientists observed memory- like recognition in animals, most psychologists dismissed the possibility of memory in non- humans until the later half of the 20th century. However, by mid-century, scientists began making progress in short-term animal memory research. Scientists reported that animals rely on cognitive maps, were successful at matching-to-sample tasks, and could understand list-learning tasks (Honig & James, 1971; Roitblat & von Fersen, 1992; , Miller & Jagielo, 1990; Wasserman, 1993). However, these tasks tend to focus on animal memory span in terms of seconds, minutes or hours. Long-term memory studies have been scarce. There are two main for the difficulty in studying long-term memory in animals: the fact that most studies of long-term memory rely on self-report from the participant, which is impossible in non-language trained animals; and the difficulty in identifying observable behaviors that may satisfy either episodic or semantic memory requirements (Clayton et al., 2003).

ANIMAL LONG-TERM MEMORY STUDIES Researchers first considered long-term memory capabilities in animals when studying the food-caching habits of birds (Balda & Kamil, 1992). After observing the caching behavior of wild Clark’s nutcrackers (Nucrifraga columbiana), the researchers devised an experiment to test the nutcracker’s ability to remember their caching sites up to 285 days later. Captive nutcrackers were allowed to cache up to 25 food items in an enclosure with 69 cache sites. When allowed to retrieve the items up to 285 days afterward, their success in recovering cached items was significantly above the amount expected if they had recovered randomly. This suggested that the nutcrackers remembered the locations of their caches over

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extended periods of time, and that their success in recovering these caches did not rely on blind searching. Clayton and Dickinson (1998) built upon the Balda and Kamil (1992) study by researching long-term memory in scrub jays (Aphelocoma coerulescen). However, they also wanted to investigate, not only the long-term spatial abilities in birds, but also their possible capacity for episodic memory. Clayton et al. (2003) outlined their criteria for “episodic-like” memory in animals. The animal must be able to remember what happened, as well as where and when it occurred. All these components must be “directly connected” to the same event (p. 686). The information must also be flexible, in that it can be used in new situations. This would set the information apart from simple motor-skill (implicit) learning. In the Clayton and Dickinson (1998) experiment, the jays were offered wax worms (which were highly perishable) and peanuts (low perishability) to cache in their cage for later consumption. The jays were then locked in an adjacent cage for extended delays (4 hours or 124 hours). The experiment controlled for odor of decay after a long delay. When the jays were allowed back in the cage after 4 hours, the jays would head directly to the wax worm caches. If the delay was 124 hours, the jays would recover the peanuts with no regard for the wax worms. This demonstrated that the jays remembered where the items were hidden, and how long they had been cached. Clayton and Dickinson. (1998) argue that the jays’ knowledge of what they cached, where they cached it, and when they did so qualifies as “episodic-like” memory in birds. Their argument has been successful enough for Tulving himself to admit that some animals may have “episodic-like” memory capabilities (Tulving, 2002). Menzel (1999) continued this type of long-term memory research with a symbol- trained chimpanzee named Panzee. Panzee learned to communicate with humans by using geometric symbols called lexigrams, which were displayed on a keyboard (Rumbaugh, 1977). She could press the symbols to answer questions or request items. In this experiment, a keeper would show Panzee an object, and she would watch as the keeper left the enclosure to hide the object outside. After a delay of up to 16 hours, she would attract a keeper’s attention via gesturing and use of the lexigrams. She would then relay what object was hidden, where it was located (such as under a rock or in a tree) and occasionally recount who hid the item. This experiment demonstrated that the chimpanzee could also relay what,

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where and who, demonstrating that perhaps they also possessed the capability for episodic memory. Beran et al. (2000) studied long-term memory of lexigrams by the chimpanzee. This differed from the two previous studies because it focused on semantic memory rather than on episodic memory. Lana was the first chimpanzee to be taught this symbol-based language (Rumbaugh, 1977). She used the lexigrams from the inception of the program in 1970 until 1977. By the end of the study, she had learned over 100 lexigrams (Rumbaugh, 1977). She used them in sentences, and even created novel phrases for items when she did not have a lexigram for the item. For instance, when given a cucumber, for which she had no lexigram, she called it a “banana which-is green” (Hillix & Rumbaugh, 2004). In 1977 she was returned to her original chimpanzee colony until the early 1980s (Beran et al., 2000). During that interval, she did not have any contact with lexigrams. When she was returned to language research in the early 1980s, some of the original lexigrams had been removed, and new ones added. During Beran’s (2000) experiment, she was asked to use some of the original lexigrams she had not seen in over 20 years. During the experiment, an item was placed on a table near her computer. She was asked questions such as “What name-of this,” or “What color this.” These questions were similar to those asked of her during her training in the early 1970s (Beran et al., 2000; Rumbaugh, 1977). She responded correctly 92% of the time (Beran et al., 2000). This research was revolutionary in that it was the first study to investigate animal memory over the course of not just months or years, but decades. This was possible because of the chimpanzee’s long lifespan (over 60 years in captivity) and the fact that the information being recalled was a language, rather than the location of something in the external environment. Trying to control an environment (such as a cache location or a hidden object in an enclosure) for dozens of years would likely be impossible.

APE LANGUAGE RESEARCH Humans have always been fascinated with the possibility of conversing with other animal species. As great apes have physiological, morphological, and behavioral traits similar to those of humans, many have pondered their ability to communicate. In 1661, Samuel Pepys, on seeing a “great ” remarked “I do believe that it already understands much English, and I am of the mind it might be taught to speak or make signs” (Pepys, 1893

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p.82). Primatologist Robert Yerkes and Margaret Child (1927, p.54) also surmised that apes might be able to communicate, stating “Perhaps they can be taught to use their fingers, somewhat as does the deaf and dumb person, and helped to acquire a simple, nonvocal sign language” (p.180). However it was apparently generally assumed that chimpanzees lacked the ability to learn and use a gestural language. This assumption persisted until a husband and wife research team from Reno, Nevada demonstrated what Pepys and Yerkes had already supposed. Apes could learn to use the gestural language of the deaf.

WASHOE R. Allen and Beatrix Gardner decided to teach an infant chimpanzee a gestural language, as other experiments had indicated that chimps would never learn to speak (Hayes, 1951; Kellogg & Kellogg, 1933). Since chimpanzees were shown to be adept at using tools and making gestures similar to human gestures, the Gardners believed they could teach a chimpanzee American Sign Language (ASL). They acquired a wild-caught infant that was estimated to be between 8 to 14 months old, who they named Washoe. Their research design was tailored to her being treated much like a human child, with confinement being minimal, and having stimulating interactions with human caregivers during all waking hours (Gardner & Gardner, 1969). They hoped that Washoe would go beyond simple rote answers such as the identifying of objects. They wanted her to ask questions about the world, and answer questions they posed. They hoped to “develop behavior that could be described as conversation” (Gardner & Gardner, 1969, p. 665). The Gardners originally considered using spoken words as well as ASL, but soon abandoned the idea. They did not want Washoe to understand spoken words, for fear that she would abandon gestures altogether. All interactions with Washoe by her caretakers were in ASL, and they were not supposed to speak in her presence. In the beginning, the Project Washoe caregivers expected Washoe to imitate the signs they were producing. As chimpanzees are great imitators, they believed that she would begin to copy the signs she was shown (Gardner & Gardner, 1969). They also shaped her responses in order to teach her correct signs. If she made a gesture that was an approximation of a sign, they would reward this gesture. Then she would gradually have to become more precise in making the correct sign to receive a reward. Her rewards consisted

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of smiles, clapping, tickling, giving her an object she desired, and occasionally food. Ticking seemed to be the most reinforcing reward (Fouts, 1997). Imitation and shaping did work in teaching Washoe signs, but it was slow, arduous work. The Gardners also found that while Washoe could understand many of the signs, she would not always sign them herself (Fouts, 1997; Gardner & Gardner, 1969). This mirrors the order of language acquisition in human infants, in that comprehension preceded production (Steinberg & Sciarini, 1993). While imitation and shaping worked in teaching Washoe to produce signs, graduate student and caretaker Roger Fouts found that molding yielded much better results (Fouts, 1997; Gardner & Gardner, 1969). Molding consisted of the teacher physically manipulating the hand into the correct sign, and also creating the proper hand movements (Fouts, 1973). Once this mode of teaching began, Washoe could learn a sign in one to two sessions (Fouts, 1997). A sign became a candidate for a legitimate vocabulary word when three separate observers saw Washoe use the sign spontaneously. At that point, she had to use the sign appropriately for 15 days in a row (Gardner & Gardner, 1969). Once she had 8-10 signs in her vocabulary, she began spontaneously using signs in strings of multiple signs. Caretakers had always used strings of signs when conversing with her. If she had simply been imitating her caretakers, the strings would have been the exact same words in the same order. However, she came up with novel strings, and even invented strings such as OPEN FOOD DRINK for the refrigerator, when the caretakers had always called it the COLD BOX (Fouts, 1997). By 1970 she was using 132 signs regularly, and could understand hundreds of others (Fouts, 1997). She also understood “transfer referents”- meaning she understood that the sign for hat did not just mean the hat in front of her, but all hats (Gardner & Gardner, 1969). Washoe also “babbled” by signing to herself. She did this when learning a new sign as a way of practicing it. She also signed to herself when looking through books or magazines, even if a caretaker was not engaging her in conversation (Fouts, 1997). Once the Gardner’s accomplishments were published, other researchers began to examine the language capabilities of apes. Patterson & Linden (1981) investigated the ASL capabilities of a gorilla named Koko, and Miles (1993) taught ASL to an named . Other modes of communication were also studied, primarily with chimpanzees. These included the use of plastic tokens (Premack & Premack, 1972) the lexigraphic

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language using a keyboard (Rumbaugh, 1977; Savage-Rumbaugh & Fields, 2000), and Arabic numerals (Matsuzawa, 1985). Fouts went on to expand the Gardner’s initial ASL research while at IPS.

FOUTS’ APE ASL STUDIES One issue that plagued the Gardner’s research with Washoe was whether she was simply a highly intelligent chimpanzee who was unique in her ability to sign, or whether all chimpanzees could learn to sign. When Project Washoe came to a close, the Gardners sent Washoe and Fouts to the Institute for Primate Studies (IPS) at the University of Oklahoma (Fouts, 1997). IPS had a colony of 19 chimpanzees residing on the property (Miles, 1978). Among them were four juvenile chimps named Booee, Bruno, Thelma and Cindy. Booee was born at a research facility in Bethesda, Maryland, but home-reared for his first 3 years of life. Bruno was born at IPS, but was also home-reared for approximately 3 years. Both Thelma and Cindy were wild-caught as infants, but were comfortable with human contact and readily handle-able (Fouts, 1973). Fouts decided to attempt to teach these four chimpanzees ASL to determine whether or not Washoe’s ability was unique. At the time of the study, Booee was 36 months old and Bruno 32 months. Thelma’s age was estimated to be between 45 and 51 months, and Cindy’s between 33 and 39 months (Fouts, 1973). The chimpanzees were taught individually in a 6-foot long by 3-foot wide training cage with a bench at each end. The human teacher would sit at one end, and the chimpanzee at the other (Fouts, 1973). While the chimpanzee was expected to pay attention during these training sessions, occasional play was permitted, as chimpanzees have a short attention span. The sessions would last for 30 minutes, with up to three sessions per day, five days per week (Fouts, 1997). The first ten signs Fouts chose to teach his new subjects came from Washoe’s vocabulary list: FRUIT, DRINK, FOOD, HAT, KEY, STRING, SHOE, LOOK, LISTEN and MORE. Most of the items corresponded to actual objects the signs represented. A ticking wristwatch was used for the sign LISTEN and a pair of glasses for the sign LOOK. The only sign without an item exemplar was the sign MORE. It was always paired with a noun, such as MORE and FRUIT (Fouts, 1973).

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The four chimpanzee subjects were taught these signs via molding. The teacher physically manipulated the hand into the correct shape sign (Fouts, 1973). After the chimpanzee allowed its hand to be molded into the correct shape, it was given a food reward, usually a raisin (Fouts, 1997). After the chimpanzee’s hands were molded a few times, questions or statements were used by the teacher to elicit signs (Miles, 1978). As the chimpanzee became more competent at making the sign without the teacher’s assistance, the teacher gradually stopped molding the hand into the correct position. Food rewards were also given when the chimpanzee made the sign without the teacher’s help (Fouts, 1973). According to Fouts (1973) to measure the acquisition time for each sign, The experimenter recorded the times for (i) the first correct response that immediately followed the molding of the chimpanzee’s hands, (ii) the first correct response not preceded by a prompt or any aid from the experimenter, and (iii) the first five consecutive correct unprompted responses to the exemplar. (p. 978-979) The vocabulary words were taught in random order. Certain signs seemed easier for the chimpanzees to learn (Fouts, 1973). All four subjects learned LISTEN, KEY, DRINK, and SHOE quickly, while STRING and HAT were more difficult (based on acquisition time in minutes.) Fouts (1973) surmised that certain signs are similar to hand movements chimpanzees make naturally, so perhaps they were more easily learned. For example, the sign for drink was a closed fist, with thumb extended, brought to the mouth (Miles, 1978). Chimpanzees often suck their thumb, which is similar in form and action to the DRINK sign (Fouts, 1973). Fouts (1973) also mentions that the sign for LOOK (the index finger brought near the eye) may be more difficult to learn because chimpanzees do not readily stick their fingers near their eyes, and in fact are averse to things coming near their eyes. A sign was considered reliably learned when the chimpanzee used it five times in a row with no prompting (Fouts, 1997). The sign acquisition rates were as follows: • Subject Minutes on Average to Learn a New Sign • Booee 54 • Cindy 80 • Bruno 136 • Thelma 159 On first glance, it seems intuitive that Booee was the most intelligent student. However Fouts (1973) states that their learning styles greatly influenced their acquisition

15 rates. Booee was highly food motivated. According to Fouts (1973), Booee “can best be described as a chimpanzee willing to sell his soul for a raisin” (p. 979). He would sign quickly and often in order to receive his food reward, but he “sacrificed quality for quantity” (Fouts, 1997, p.143). His signs were often frantic and poor in form (Fouts, 1997). Booee’s responses also fell apart during double-blind testing. In this procedure, a box was placed in the training cage in which sign exemplars could be inserted. An assistant sat behind a blind, and would insert the exemplars. One observer would sit next to the box, but out of view of the exemplar. This observer would ask “What that?” in ASL. A second observer was located off to the other side of the box would record the chimpanzee’s answer. This second observer was also out of view of the exemplar (Fouts, 1973). Once Booee learned that no rewards were given during double-blind testing, his correct answers plummeted (Fouts, 1997). His tally of correct responses during double-blind testing was 58.3 percent (Fouts, 1973). Cindy’s learning style was similar to Booee’s. She did not care so much for treats as for verbal praise from her teachers. After a correct answer, Cindy expected heaps of congratulations. Fouts even enlisted assistants to sit outside the training cage to cheer her on during the acquisition phase (Fouts, 1997). As Cindy’s rate of acquisition was second to Booee’s, her praise rewards were obviously highly motivating. However, her answers also deteriorated during double-blind testing when her answers were not rewarded. Her tally of correct responses during double-blind testing was 26.4 percent (Fouts, 1973). Because of his high comprehension of spoken English, Fouts (1997) considered Bruno one of the smartest chimpanzees at IPS. However, Bruno had no to learn ASL. The sign for hat is to place one’s open, flat hand on top of one’s head (Miles, 1978). Fouts would place Bruno’s hand on top of his head during the molding process, but once he would let go of Bruno’s hand, Bruno would let it fall dejectedly (Fouts, 1997). His ambivalence caused Fouts to increase the value of the rewards. Bruno was offered an array of fruits and even soda, to no avail. As Fouts knew of Bruno’s , during one training session he picked up a prod (which IPS required that employees carry at all times) and turned it on. Bruno immediately began signing HAT repeatedly. From that point on, Bruno knew that Fouts had called his bluff, and he became one of the best signers in the experiment (Fouts, 1997). Bruno was slower during the acquisition phase because of his reticence, but scored

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highest during double-blind testing. His tally of correct responses was 90.3 percent (Fouts, 1973). This led Fouts (1997) to comment that although he learned more slowly, he remembered what he learned. Thelma was also a slow learner who cared nothing for food rewards. According to Fouts (1973) Thelma was easily distracted. She could completely lose focus if a fly entered the cage. She was also stubborn, and tried to prove that she often had better things to do than learn signs. She was considered a “dreamer” or “a good example of attention deficit disorder” (Fouts, 1997, p. 145). Despite her distracted , she scored 59.6 percent correct in double-blind testing (Fouts, 1973). All four chimpanzees learned all ten signs (Fouts, 1973). Fouts concluded that the ability to learn ASL was not unique to Washoe. This ability was also demonstrated in other chimps (Fouts, 1997; Gardner & Gardner, 1989), a gorilla (Patterson & Linden, 1981) and an orangutan (Miles, 1993). While the 1970s gave rise to a plethora of ape language research, the 1980s almost signaled its death. Critics and skeptics of the research kept interest alive, but funding began to wane (Linden, 1986). The 1980s and President Ronald Reagan ushered in the era of finding a “cure for cancer,” which diverted most scientific research money to medical research (Fouts, 1997; Linden, 1986). The Institute for Primate Studies was particularly affected by lack of funds for behavioral research, and its director, William Lemmon began to bid contracts to biomedical companies for use of the Institute’s primate populations (Fouts, 1997; Linden, 1986). By 1980, Fouts had moved Washoe and a few other chimps belonging to the Gardners to Central Washington University (Fouts, 1997). Between 1978 and 1982, Lemmon had bid unsuccessfully to have his chimpanzees used as subjects of Hepatitis B and other medical research (Fouts, 1997). In 1982 he decided to liquidate his entire chimpanzee colony by sending them to the Laboratory for Experimental Medicine and Surgery in Primates (LEMSIP), (Fouts, 1997). This included the ASL-speaking chimpanzees Booee, Bruno, Thelma, and Cindy (Fouts, 1997).

BOOEE Booee (Pan troglodytes) was born on October 23, 1967 (Miles, 1978). He was born at an NIH facility in Bethesda, MD. The researchers studying his mother did not know she

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was pregnant, so after his arrival he was not immediately scheduled for a specific study (Fouts, 1997). When he was just a few days old, he convulsed, which led researchers to believe that he might be epileptic. At the time, the newest experimental treatment for epilepsy was a corpus callosotomy, more commonly known as a ‘split brain’ operation. During a corpus callosotomy, the brain is cut down the middle, dividing it into two symmetrical halves. After the surgery, the two hemispheres can no longer communicate with each other, although behaviors like speech or motor activity are generally unaffected (Carlson, 1999). This surgery was so drastic that Booee experienced post-operative swelling, and his skull had to be reopened to relieve the pressure on his swollen brain (Fouts, 1999). A doctor at NIH named Fred Schneider witnessed Booee’s suffering, and decided to bring him home to nurse him back to health. His wife Maria and their six children also aided in Booee’s recovery (Fouts, 1997). Luckily for Booee, the NIH doctor in charge of his aftercare fell ill, so Booee’s whereabouts fell through the cracks. Once Booee regained his health, he was adopted into the Schneider family. This family home afforded him a happy life. He became very attached to his human siblings, and they treated him much like a human infant. Unfortunately, Booee’s chimpanzee biology caught up to him. At 3 years of age, he was growing into adolescence. He would hang from the living room curtains, and constantly raid the kitchen pantry (Fouts, 1999). His strength was increasing by the day, and he became much harder to handle. If a stranger or a dog walked by the Schneider home, Booee would do a threat display. These displays would end with him “thumping” the picture window with the back of his hand. After the window was broken multiple times, the Schneiders realized their home was no longer a proper place for a growing chimpanzee (Fouts, 1999). The Schneiders felt that sending Booee back to NIH to a life of biomedical experiments was not an option. In 1970, Dr. Schneider flew to Reno to ask Allen Gardner’s advice. Dr. Gardner was in the process of dismantling Project Washoe at the time, and he had planned to send Washoe to IPS in Oklahoma in the coming months. He convinced Dr. Schneider that Booee could find a new home there as well (Fouts, 1997). Booee had been residing at IPS for a few months before Fouts and Washoe arrived (Fouts, 1997). Once Washoe was integrated into the colony, 19 chimpanzees were residing

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on the property (Miles, 1978). Most of them were housed in a 40 by 40 foot building that contained seven cages. The cages were made of chain-link, and while separate from each other, they were connected to each other by tunnels. The cages were completely bare, with concrete floors (Fouts, 1997). The chimpanzees were housed in these seven cages in small social groups (Miles, 1978). This was a far cry from the environments in which Booee and Washoe had grown up. Booee’s social group generally consisted of the other sign-language trained chimps Washoe, Bruno, Thelma and Cindy, but occasionally included those being integrated into the general chimp population (Linden, 1974). Booee and Bruno were inseparable. Booee was the sweet and silly wingman to Bruno’s proud and domineering leadership (Fouts, 1997; Linden, 1974). All the ASL-trained chimpanzees were given name signs by their teachers. Fouts (1997) created Booee’s name sign, made by “drawing the index finger over the top of the head from back to front” (p. 135). This referred to his corpus callosotomy surgery, in effect meaning “BOOEE SPLIT-BRAIN” (Fouts, 1997, p. 134). Fouts (1997) notes that he did not observe any serious complications from the surgery- although he does mention that during piggy-back rides, Booee would point in two different directions at the same time. Also, when he painted, he would only use the opposite corners of the page. After Fouts’ original study (1973) with these four chimpanzees (as noted in the previous section), one of his next projects was documenting between-chimp conversations (Miles, 1978). Booee’s and Bruno’s relationship afforded Fouts the opportunity to witness many such conversations (Linden, 1974). Most conversations between the two consisted of asking each other for food or a tickle (Linden, 1974; Miles, 1978). In 1974, Lyn Miles, notable for her later work with Chantek, the ASL-using orangutan, began her dissertation research at IPS. She studied the content of conversations between chimpanzees and their human teachers (Miles, 1978). She chose Booee and another chimpanzee named Ally for her study. By this time Booee’s vocabulary consisted of approximately 40 signs (See Appendix A). During the pilot phase of her study, Miles noticed that the conversations between teachers and chimpanzees outside of the experimental design were more relaxed and unusual. This led her to create a research environment in which both the teachers and chimpanzees would not feel under scrutiny. She recorded ten

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15-minute conversations with both Ally and Booee. The teachers in the study were Roger Fouts or graduate student Joe Couch (Miles, 1978). The sessions took place outdoors near the IPS pond. Miles and her video-camera were placed near a tree 15 feet away from the conversants. This atmosphere lent itself to play and relaxed interaction, and Miles was inconspicuous enough that she generally did not disturb the sessions. Booee only reacted to Miles once, gesturing for her to come and join in the conversation (Miles, 1978). Before a session started, toys and objects were placed in the conversation area in order to stimulate conversation. These items included objects Booee knew the signs for, and novel objects like a feather duster, a teddy and a wooden rice paddle (Miles, 1978). Conversations often began with the teacher asking, “WHAT THIS?” or to initiate play. Conversations with Booee focused more on food than the objects in the area, confirming Fouts’ (1973) assertion that the food-motivated Booee would “sell his soul for a raisin” (p. 979). When Booee did pay attention to the objects available, he was more interested in manipulating them than in naming them (Miles, 1978). He was most interested in items he could perform an action with, such as a broom, hammer or rake (Miles, 1978). According to Miles (1978) “he had good manual dexterity and he showed great concentration during these activities” (p. 74). He was often uninterested in non-functional items, which made engaging in conversations about them difficult. When Miles (1978) transcribed her recordings, she found that Booee used 54% of his vocabulary words during these conversations. According to Miles (1978), the top ten signs he used (in decreasing frequency) were: Booee (241 times), tickle (211 times), you (96 times), this/that (77 times), food (65 times), hurry (31 times), me (29 times), gimme (25 times), there (25 times), and fruit (17 times). He also used signs in combinations, his longest being strings of six signs. Each string was unique, but he did repeat words in his strings. His combinations were usually signed in increasing intensity in order to beg for food, such as “GIMME THERE FOOD BOOEE HURRY” (Miles, 1978, p. 67). Miles (1978) asserts that Booee’s strings also followed rules of grammar and understanding of pronouns. For instance, Booee requests a tickle (Miles, 1978, p. 68): • Booee: SHOE BOOEE TICKLE • Roger: (tickles Booee with his shoe) • Booee: SHOE ME

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• Roger: (tickles Booee again) • Booee: SHOE TICKLE ME Here is another example of Booee’s understanding of pronouns (Miles, 1978, p. 69): • Roger: YOU • Booee: ME • Roger: YOU TICKLE ME • Booee: (tickles Roger) When Roger signed YOU, Booee did not merely imitate his sign. He responded with ME. Roger then signed YOU TICKLE ME, and Booee performed the correct action by tickling him (Miles, 1978). Miles (1978, p. 59) also noted that, when asked about an object they had not learned a sign for, Ally and Booee frequently named it BABY. It was as if signing BABY was their way of saying “I don’t know.” Miles’ (1978) analysis of Booee’s and Ally’s signing demonstrated that they used signs as a channel of communication and social interaction. They were not performing conditioned responses in order to beg for food. Her analysis concluded that based on their sign performance, order, acquisition, and competence, they used signs at the same level as two-year-old children (Miles, 1978, p. 131). Her painstaking transcription of Booee’s and Ally’s conversations helped to prove that apes were able to carry on meaningful conversations with their human caretakers. Booee continued participating in ape language research at IPS until his transfer to LEMSIP in May of 1982. Although there was a great public outcry when the “famous” ASL chimps were transferred to LEMSIP, Lemmon asserted that he was confident the chimpanzees would be well cared for by the lead veterinarian, Jim Mahoney (Linden, 1986). But life at LEMSIP was a far cry from what the chimpanzees at IPS were used to. Each chimpanzee was housed in a solitary 5 x 5 x 6 foot cage. The chimpanzees could see and call to one another, but there was no group housing or access to the outdoors (Linden, 1986). As it was a medical research laboratory, the foremost concern was to have access to the chimpanzees for blood draws or injections. The chimpanzees from LEMSIP were inducted into a Hepatitis B study, where they were injected with a vaccine, then later injected with the live virus. Blood was drawn regularly to observe the efficacy of the vaccine and to monitor

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the chimpanzee’s health (Linden, 1986). Once at LEMSIP, the chimpanzees did not stop signing, but the technicians did not know what they were saying, or how to answer their requests. Fouts (1997) heard from visitors who knew ASL that Ally, Bruno, Booee and other ASL chimpanzees regularly asked for items like food or the keys to their cages. Although their situation was much more dire than when they resided at IPS, Jim Mahoney was a compassionate caretaker (Hillix and Rumbaugh, 2004; Linden 1986). When Linden (1986) visited Booee and Bruno shortly after their move to LEMSIP, he found that a poster had been affixed to their cages describing the signs the chimps were using. The techs wanted to understand what the chimpanzees were asking for, and wanted to be able to respond. Jim Mahoney himself was interested enough to acquire a few signs (Linden, 1986). Mahoney often visited with the chimpanzees, and would even share food or cigarettes with them (Hillix and Rumbaugh, 2004; Linden, 1986). However, most of the chimpanzees’ signing declined after a few years (Linden, 1986). There is no published data regarding other experiments that Booee was subjected to at LEMPSIP, but as of 1995, Booee was said to be a carrier of Hepatitis C (ABC News, 1995). In May of 1995, Hugh Downs and the news show 20/20 asked Roger Fouts to go to LEMSIP to visit Booee (Fouts, 1999). The premise for the segment was whether or not Booee would remember his former teacher, and whether Booee would sign. Dr. Mahoney led Fouts and Downs to the room where Booee was caged. Fouts entered alone, and slowly crept up to Booee’s cage. When Booee saw Fouts, he immediately used his own name sign, the sign for food, and incredibly, the sign he had created as Roger’s nickname many years before (ABC News, 1995). A few months after the segment aired, Booee was transferred to the Wildlife Waystation, an exotic animal sanctuary outside Los Angeles, CA, where he currently resides.

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CHAPTER 3

METHODS

PARTICIPANTS At the time of this study, Booee (Pan troglodytes) was 41 years old. He was housed in an isolation cage because he carried the Hepatitis C virus. At the time of the present study, he did not have any health complications related to this infection. He was housed next to another Hepatitis C chimpanzee, whom he could see, smell and hear. However, they could not come into physical contact. He could also hear the vocalizations of other chimpanzees on the property. His enclosure consisted of a total of three large cages: the outside cage, inside cage, and outdoor cage. He would be housed either in the outside cage (with views to the neighboring enclosures), or the inside cage and outdoor cage (see Figure 1). Booee’s enclosure contained multiple perches and stands, a den box, poles to climb or slide down, and room to run around. The enclosure was constructed of chain-link fence material. Handlers could not enter the enclosure with the chimpanzees, nor could they fit more than a few fingers into the enclosure. The chimpanzees were also limited to fitting only a few fingers out of the enclosure. Food and play items could be slipped under the cages via a 1”-2” gap between the concrete floor and the chain-link bars. Despite these constraints, keepers had a limited ability to interact with the chimpanzees. During the course of Fouts’ (1997) and Miles’ (1978) studies, Booee had a vocabulary of approximately 40 signs. Since his departure from IPS, the breadth of his vocabulary has dwindled to only a few signs. As of 2009, the two he used regularly were BOOEE and FOOD. Other signs that were harder to qualify are THIS/THAT, GIMME and HURRY. THIS/THAT requires pointing at or touching the object to which it refers. GIMME is an open hand drawn toward one-self, and HURRY is an open hand being shaken insistently in front of the body (as described by Miles, 1978). I have seen other chimpanzees with no ASL training (and no visual contact with Booee) make similar gestures with similar meaning. However, Booee does seem to make these three signs with more obvious .

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Figure 1. Cage configuration.

Miles (1978) mentioned that Booee was not often interested in conversing about objects in his environment. He had to be asked or prompted before he would name the items. He also did not “babble” to himself like Washoe did. Because of this observation, it may be assumed that if no one asked Booee about items in his environment, he was not likely to sign to himself about them. Also, if his handlers did not use ASL to converse with him, most of his signing may have been gradually eliminated through extinction, i.e. the ignoring of the behavior (Pryor, 1999). The sign FOOD was often reinforced, both at LEMSIP and at the Wildlife Waystation, by giving him food. Thus it is easy to see why FOOD is such a prevalent sign in his now-limited vocabulary.

STUDY SITE The Wildlife Waystation is an exotic animal sanctuary located in the Angeles National Forest, approximately 25 miles northwest of downtown Los Angeles. The sanctuary houses over 400 animals on 160 acres in a rural setting of a national park. Forty- six chimpanzees resided on the property at the time of the present study. All were housed in

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social groups except for Booee and one other Hepatitis carrier. Booee has resided at the Wildlife Waystation since 1995.

RESEARCH DESIGN In the present study, Booee was presented with five items from his original vocabulary list. When asked “WHERE [item]” in ASL, he was expected to point to the correct item. Items were presented on an apparatus in groups of four. He was taught to point to a target (a red dot) on the apparatus to choose the corresponding item. The hypothesis for this study was that Booee would point to the correct item at above chance levels. As a control measure, he was also shown five items for which he had never learned the signs. When asked to point to these items (also in groups of four), it was supposed that he would answer correctly at chance (25%). His correct answers when asked about the ‘old’ signs may demonstrate that he remembered these signs, and possesses long-term memory capabilities for them. Signs were chosen from Booee’s original ten-sign vocabulary, as listed by Fouts (1974). FOOD was excluded because Booee still used this sign. DRINK was excluded because of its similarity in sign form to FOOD. MORE was excluded because it is a , and did not have an item exemplar. FRUIT was excluded because Fouts (1974) did not describe the fruit exemplar in detail. LISTEN was excluded because of the difficulty in finding a loudly ticking wristwatch (as used by Fouts, 1973). These exclusions led to an ‘old’ sign vocabulary list of HAT, KEY, SHOE, STRING and LOOK. Each of these signs had an item exemplar as described by Fouts (1973). For this experiment, the HAT was a baseball cap, the KEY a common house key, the SHOE a tennis shoe, the STRING a 15-inch piece of rope similar in diameter to a shoestring, and LOOK by a pair of glasses. Signs chosen for his ‘new’ vocabulary list were based upon their similarity to his ‘old’ signs. This was to ensure that Booee was truly recognizing the individual chereme differences in the signs: the configuration of the hand, the bodily location of the sign, and the hand movement (Stokoe, 1960). The signs chosen for his ‘new’ vocabulary list were: FEATHER, GLOVE, SOCK, TOY and FLOWER. As an example regarding the similar cheremes of the signs, HAT is signed by placing a flat hand, palm down, on the top of the

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head. FEATHER, a vocabulary list on his ‘new’ sign list, is made by simulating the plucking of a feather from the top of the head with the thumb and forefinger. Both signs use only one hand, a simple action is performed, and the location is at the top of the head. See Appendix B for descriptions of all signs, and to compare form, location and movement. The exemplars for new signs were as follows: FEATHER was a large red feather, GLOVE was a black cotton women’s glove, SOCK was a white cotton sock, TOY was a small toy train, and FLOWER was a pink silk rose. Focusing on Booee’s comprehension of signs instead of production of signs was chosen because comprehension occurs first in language acquisition (Gasser, 1995; Steinberg & Sciarini, 1993). One must understand the meaning of words before using them in a meaningful way (Steinberg & Sciarini, 1993, p. 23) This is true regardless of the sensory modality of the language (Gasser, 1995). The present study focused on Booee’s comprehension of ASL because it was expected to be greater than his success at production of signs.

PREPARATION In preparation for this study, I completed American Sign Language I, II and III at San Diego Mesa College from January of 2006 to December of 2007. After completion, I was considered of intermediate fluency in ASL. I have also studied positive with regard to since 1997. I have completed Extended Studies classes in and training from SDSU in 1997, as well as completed an animal training internship with the U.S. Navy Marine Program in 2000. I have continued to practice these training skills through training dogs and cats. I am confident in my ability to use positive reinforcement and reinforcement schedules in training animals.

APPARATUS The apparatus that was used to display the item exemplars was a four-foot long wooden table. It was 14 inches wide, and 7 inches tall. It was easily placed flush against the chain link enclosure, and Booee could easily place his fingers through the chain link in order to touch it. The table was divided into four equal sections by a thin piece of wood that was painted blue. This clearly denoted the boundaries between sections. The red target dots were

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painted directly in the middle of each section, and were 1.25 inches in diameter. (see Figure 2).

Figure 2. Apparatus.

TRAINING The training process consisted of four phases before data collection began. Phase I. Teaching him to recognize the WHERE sign. I assigned a name sign to a small stuffed animal, the sign for HAPPY. For three days, I showed him the stuffed animal and signed THAT HAPPY. Then I began placing the item in front of him, or to left or right and asking WHERE HAPPY? When he pointed to or touched the item, he was reinforced with one raisin. These sessions lasted for approximately 10 minutes, up to three times a day. The criterion for moving to Phase III was Booee’s answering correctly 10 times in a row in one session, for five consecutive sessions. Phase II. Booee was trained concurrently to Phase I, but in separate sessions, to target on red dots on the apparatus. First, I pointed to red dot, and when he touched red dot, he was reinforced with one raisin. At least ½ of his finger needed to be touching the red dot for it to count as a correct answer. These sessions lasted for approximately 10 minutes, up to five times per day. The criterion for moving to Phase III was Booee’s targeting correctly 10 times in a row in one session, for five consecutive sessions. Phase III. Booee needed to combine answering the question WHERE HAPPY? with choosing it by targeting on the corresponding red dot. The stuffed animal was placed in one of four sections of the apparatus. When asked WHERE HAPPY?, he was reinforced with two raisins when he targeted on the corresponding red dot. These sessions lasted for 10

27 minutes up to five times per day. The criterion for moving to Phase IV was his answering correctly 10 times in a row for two consecutive sessions, two consecutive days in a row. Phase IV. Booee was taught to discriminate among items to choose HAPPY on the apparatus. Items that were not on his vocabulary list were placed on each section of the apparatus. Besides HAPPY the stuffed animal, the items consisted of: a spoon, a pen, and the top to a small metal canister. When asked WHERE HAPPY?, he was expected to choose the stuffed animal by targeting on the corresponding red dot. If he chose correctly, he was given two raisins. If he chose incorrectly, he was verbally told no. Each session contained 15 trials where the items were randomly moved to different sections on each trial. When Booee’s correct answers to the question WHERE HAPPY reached 70% or more for five consecutive sessions, data collection began. These sessions lasted for up to 15 minutes, no more than four times per day.

CHANGE IN RESEARCH DESIGN BASED ON TRAINING TRIALS The apparatus originally included a screen that was raised between each trial so Booee would not be primed by possibly wanting to choose the last item that I placed on the apparatus. However, in this added “down time” between the trials, he began a superstitious behavior of targeting on a dot (or multiple dots) before the screen was lowered again. I tried to extinguish this behavior by: not lowering the screen until he had refrained from touching it for 5 seconds, by telling him no when he targeted prematurely, and by trying to reinforce his not touching the apparatus while the screen was up. This attempt at extinguishing his pre- emptive targeting lasted for more than ten sessions. However, in his frustration he would continue to target on dots despite not being reinforced. He also began flicking and scratching the apparatus when the screen was raised. I removed the screen and changed the method of displaying the item exemplars. I would set out the items, then bring both my hands behind my back for 5 full seconds before asking WHERE [item]? This eliminated his superstitious behavior of choosing a target before seeing the items. He also began focusing his gaze on my face and waiting for me to make a sign before he started to target. As I displayed the items on the apparatus in a group all at once, there was no for him to cue on the first or last item that was placed.

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DATA COLLECTION Booee’s testing vocabulary consisted of 10 signs: ‘old’ signs HAT, KEY, SHOE, STRING, and LOOK, and ‘new’ signs FEATHER, GLOVE, SOCK, TOY and FLOWER. Data sheets were created to specify the placement of items on each trial, and to denote which item would be requested on each trial. An empty data sheet with four columns (representing the four sections of the apparatus) and 20 rows (representing each trial) was created. A random order for item placement was assigned by pulling index cards from a bag. One card was pulled from the bag at a time. As each item was pulled, it filled a consecutive slot on the data sheet. For instance, the first card would fill the first slot in Column A, the second card Column B, etc. As there were only four columns, but five items, the fifth card carried over to Column A on Trial 2. Once an item card was pulled from the bag, it was held out until all cards had been pulled, then all the cards were placed back in the bag for beginning again. Drawing cards from the bag occurred until all rows/columns were filled on the data sheet. Choosing which item would be asked for during a trial was also chosen by pulling cards from a bag. Cards for Column A, B, C and D were created. If the card for Column A was chosen, then the item in Column A on trial 1 was circled. Once a Column card was chosen, it was held out until all Column location cards were picked- then all cards were placed back in the bag. This continued until a column was chosen for each row on the data sheet. Three data sheet templates were created in this fashion. The three sheets were then repeated in order to create 30 total data sheets, 15 for the ‘old’ signs, and 15 for the ‘new’ signs. Once the data sheet templates were created, they were typed, and the item to be asked was written in CAPS. (See Appendix C). This made for easy identification of which item was to be asked.

PILOT STUDY Before I signed any vocabulary words to Booee during data collection, it was recommended by Rumbaugh (personal communication, 2009) to investigate whether Booee would spontaneously make the signs from his old vocabulary list. Booee was given each item (HAT, KEY, SHOE, STRING and LOOK) to investigate and freely manipulate. During

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a session, he was asked “WHAT THAT?” in ASL, similar to prompting by Fouts (1973) and Miles (1978). He had no interest in the SHOE or STRING, but he did spontaneously sign HAT (six times in six sessions); KEY (five times in six sessions); and LOOK (two times in six sessions). The first time he was given the KEY, he first signed BABY, then after manipulating the KEY, signed KEY. This is similar to observations by Miles (1978) that Booee would use the sign BABY to say “I don’t know.” However once he considered it, he did make the correct sign for KEY. In order to document truly spontaneous signing, Booee was not reinforced after making these signs. When a behavior is reinforced, the instances of the behavior are likely to increase (Pryor, 1999). Had I reinforced Booee with food or attention for making a sign, his likelihood of making the sign would have increased. If my goal had been to train him to sign more often, reinforcing him might have been warranted. However I was investigating whether he remembered the signs. I did not want to interfere in any way with the possibility that he would make the signs in the course of conversation, rather than as a means of receiving food.

EXPERIMENTAL DATA COLLECTION Depending on which cage Booee was occupying, the apparatus was placed in one of three areas (See Figure 1). These were the only areas available to place the apparatus in which perches, poles or water fountains would not get in Booee’s way. Trials lasted approximately 10 minutes each. When the apparatus was placed on the ground in front of Booee’s cage, he was always eager to sit in front of it. This signaled the beginning of a session. The data sheet on a clipboard was held on my lap. During each trial, all exemplars were set on the middle of the apparatus. The exemplars were then spread out quickly from the middle outward. My hands were then brought behind my back, and Booee was expected to sit still for 5 seconds and focus his attention on me before a trial started. If he did not sit still, walked away, or looked away, the 5-second pause was started over. After the 5 second pause, Booee would be asked “WHERE [item]?” in ASL. Once Booee targeted on a dot, the item he targeted on was circled on the data sheet. If he correctly chose the item asked, he was reinforced with a verbal “good” and a small amount of food: raisins, a quarter-sized piece of orange, or a spoonful of oatmeal with brown sugar. If he chose incorrectly, he was

30 verbally told “no.” The item exemplars were then removed and placed behind my back, then the order for the next trial was placed on the apparatus, and the whole process was repeated for 20 trials on the data sheet. Once a session was over, the apparatus was removed from its cage location, and stored approximately six feet away. Booee was given at least 30 minutes of rest time between sessions. Sessions occurred one to five times per day, four days per week. On the first day, Booee was so enthusiastic, he sat in the corner of his cage closest to where the apparatus was stored, stared at it, and motioned to it repeatedly. One more session was added the first day, but subsequently the number of sessions did not exceed five per day. Data collection continued over a total of 30 sessions, 15 each for the ‘old’ and ‘new’ signs. The first ten sessions consisted of testing for the ‘old’ signs. The next ten sessions tested for the ‘new’ signs. When those were finished, he was tested on five more ‘old’ sign sessions, then concluded with the last five ‘new’ sign sessions. “Old” and “new” sign sessions were divided this way because it was expected that learning would occur after multiple sessions. Booee’s correct answers in the last five sessions of “old” signs were expected to be more likely than in the first ten sessions because he was returning to signs that were familiar to him. Once all 30 sessions were completed, data analysis could commence.

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CHAPTER 4

RESULTS

To analyze the data, tables were created to display the number of times each item was asked, his number of correct answers, the expected number of correct answers (as dictated by chance level) and the total number of times he chose each item. Tables were created for “Old” and “New” signs to display the data for the first ten sessions, the last five sessions and the grand total for all 15 sessions (See Tables 1 through 3). Table 1 displays the data for Booee’s “old” sign sessions, separated by the first 10 sessions and last five sessions. It was expected that learning would occur as the sessions progressed, and that Booee’s correct answers would increase when he returned to the more familiar “old” signs after 10 sessions of “new” signs. This was not the case. His answers when returning to “old” signs remained at or below chance levels. Table 2 displays the data for Booee’s “new” sign sessions. They are also separated by the first 10 and last five “new” sessions. His correct answers between the groups of sessions also remained at or below chance levels. Table 3 displays the grand totals for all 15 sessions of both “old” and “new” signs. Booee’s correct answers were generally at or below chance levels. For “old” signs, HAT is the only item for which his number correct is above chance. At first it appears that Booee may have remembered HAT. However, comparing the number of correct answers to the number of times he answered HAT (listed in the Tables 1-3 as *Ans,) shows that his number correct (22 out of 86) remains at chance level. He simply had a preference for choosing HAT regardless of what I signed to him. This possible preference also occurred in the “new” sign sessions with TOY. His total correct answers when asked for TOY are 50% above chance level. However, considering how many times he chose TOY, his correct answers are close to chance. Booee’s preferences may also be exemplified by his answers that fall greatly below chance. It appears that Booee deliberately avoided KEY (Table 3). Booee’s preferences for specific items may be attributed to the salience of these items. HAT was a red and yellow baseball cap. TOY was a small green and red toy train

Table 1. “Old” Signs: Times Asked, Times Correct and Total Answers

First 10 Sessions

HAT KEY LOOK SHOE STRING

Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans*

43 22 86 44 1 22 39 12 35 36 8 41 38 4 16

Expected 10.75 11 9.75 9 9.5

Last 5 Sessions

C HAT KEY LOOK SHOE STRING

Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans*

22 11 51 21 1 11 16 4 13 19 4 13 22 6 12

Expected 5.5 5.25 4 4.75 5.5

*Ans- number of times answered. When viewing the "Asked" and "Correct" columns, it looks as though Booee may have remembered the sign for HAT and chose correctly. However, when recognizing that he chose HAT far more than he was asked, it simply demonstrates that he had a preference for choosing HAT. 32

Table 2. “New” Signs: Times Asked, Times Correct and Total Answers

First 10 Sessions

GLOVE SOCK FLOWER FEATHER TOY

Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans*

48 11 28 36 6 31 35 5 32 43 6 48 38 13 61

Expected 12 9 8.75 10.75 9.5

Last 5 Sessions

GLOVE SOCK FLOWER FEATHER TOY

Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans*

21 3 13 19 3 12 14 2 10 21 4 18 25 18 47

Expected 5.25 4.75 3.5 5.25 6.25

*Ans- number of times answered. 33

Table 3. All Signs: Times Asked, Times Correct and Total Answers

Old Signs -Grand Totals for 15 Sessions

HAT KEY LOOK SHOE STRING

Asked Correct ** Asked Correct ** Asked Correct ** Asked Correct ** Asked Correct **

65 33 137 65 2 33 55 13 48 55 12 54 60 10 28

Expected 16.25 16.25 13.75 13.75 15

New Signs -Grand Totals for 15 Sessions

GLOVE SOCK FLOWER FEATHER TOY

Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans* Asked Correct Ans*

69 14 41 55 9 43 49 7 42 64 10 66 63 31 108

Expected 17.25 13.75 12.25 16 15.75

*Ans- number of times answered.

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engine. Perhaps these stimuli were more salient to him then a small piece of white rope (STRING), or a small silver housekey (KEY). A chi-square test was generated to determine if Booee’s answers (as represented by *Ans) could have occurred by chance. With X 2= 1990.27 and 9 degrees of freedom, the probability that Booee’s answers (*Ans) occurred by chance are less than .001. The salience or possible “attractiveness” of HAT and TOY were an important determinant of where Booee pointed. In summary, for all items in either the “old” or “new” groups of signs, comparing the number correct to the number expected shows that Booee consistently chose at chance levels. Even when the number correct exceeds the number expected, comparing the number correct to number of times chosen demonstrates that his correct answers remained at chance (see Table 3). When considering that Booee chose certain items (HAT, TOY) more frequently than others, it may be attributed to the salience of those items.

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CHAPTER 5

DISCUSSION

The hypothesis for the present study was that Booee’s correct answers for “old” signs would be significantly above the chance level of 25%. The data show that his correct answers (whether for “old” or “new” signs) were consistently at or below chance. The data does not support the hypothesis. The present study focused on Booee’s comprehension of ASL, rather than on his production. The data suggest that Booee had no comprehension of signs. However, informal observations during the pilot study demonstrated that he did remember signs for items. He spontaneously produced the signs for LOOK, KEY and HAT on multiple occasions. This leads me to believe that the research design did not elicit what was expected, but that does not mean he does not possess long-term memory for the old signs. The present study focused on comprehension rather than on production. This decision was made because it was feared that Booee would not sign spontaneously. If that turned out to be the case, the study would be futile. The current design was also chosen in order to create a rigorous study more fitting for a thesis. Although the current data did not support the hypothesis, it met the goals of rigorous investigation of a problem. Looking back, using a correction procedure might have taught Booee what was expected of him in a more meaningful way. In the current study, if Booee answered incorrectly, he was told ‘no’ and the next trial began. In a correction procedure, he would have been asked for the item until he chose the correct item. Although those trials would not count toward the grand totals, they might have better taught him what was expected of him. Whether or not a correction procedure would have changed the ultimate outcome is unknown. It remains possible that Booee did retain long-term memory for the signs he had previously learned, but was unable to retrieve the information. For example, Harre and Lamb (1983) note that

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Memory requires both encoding (or storage) and retrieval (or production). Retrieval failure appears to be the main cause of forgetting… Retrieval depends on how successfully the context of encoding is reinstated at the time of retrieval. The retrieval cue must match at least in part the encoding context. (p. 536) It may be that my signing was not sufficiently similar to the signing of Fouts (1973, 1997) for the cues (my signing) to be successful for retrieval. Also, the context presented (four items at a time, etc.) was not similar enough to the contexts in which Booee learned. Booee was trained on one sign at a time, and when he learned signs for objects he was generally allowed to manipulate and sometimes consume the item. As Miles (1978) stated, if Booee was not able to actively use an item, his interest waned (p. 74). His inherent boredom if not able to manipulate items, and the deviation from the original training environment, likely hindered his ability to retrieve memories for the signs. It is also generally recognized that older humans sometimes have difficulty in retrieval, and Booee is at an advanced age for a chimpanzee. The results clearly indicate that future research with long-term memory of ASL in a chimpanzee needs to reproduce the learning situation more closely than did the present procedure. Thus one cannot conclude from the experimental results of the present study that Booee has no long-term memory for the signs that he previously learned. The casual observations of his sign production tend to indicate the opposite conclusion.

CONCLUSION AND RECOMMENDATIONS A clear recommendation for future research on this topic is that the study focus on a production test as well as a comprehension test. The setting should more closely replicate his original training sessions in order to allow for maximum production and memory retrieval. The use of videotaping sessions is necessary to insure objectivity in evaluating Booee’s signing. Evolutionary and comparative psychologists study primates in order to understand the evolution of human cognitive processes. How these primates interact with their environment may help us understand the processes via which human cognition evolved. Defining whether or not primates have the capacity for long-term memory can help researchers to understand the complexities of human cognitive evolution. This study examined the long-term semantic memory of a gestural language in a chimpanzee. Not only does his production of signs demonstrate that he may possess long-term semantic memory, it may also assist in the

38 understanding of human language origins. Hewes (1973) hypothesized that human verbal language origins likely evolved from a gestural language. Long-term memory is required to remember and understand the words and symbols necessary for language (Tulving, 1972). The current research demonstrates that chimpanzees may have the capacity for long-term memory of a gestural language. This provides an example to support Hewes’ theory. Booee’s preference for salient items may also assist in understanding language acquisition in language-disabled humans. Choosing highly distinctive or “attractive” stimuli during teaching may make the mental connection between stimuli and language more salient. Booee’s sign production when allowed to manipulate the items may also indicate that the cross-modal integration of visual and tactile stimuli leads to greater success at producing language (Davenport & Rogers, 1970; Hewes, 1973). This understanding may also be used when teaching language to human infants. Regarding animal memory, the majority of long-term memory studies focus on their capacity for episodic memory. There is great debate about this ability, especially because psychologists consider it a benchmark of what makes us “uniquely human” (Tulving, 1972). As episodic memory cannot exist without semantic memory (Tulving, 1984) it begs the question: why focus all the attention on episodic memory if we have not definitively proven the existence of semantic memory in non-humans animals? This study attempted to demonstrate the existence of semantic memory of a language in an ape. Although the experimental procedure did not support the hypothesis, Booee’s spontaneous production of signs may demonstrate that he possesses semantic memory for American Sign Language. Hopefully this addition to the literature will encourage others to examine semantic memory in animals more closely in order to build a foundation for understanding the development of episodic memory.

ETHICAL CONSIDERATIONS Conducting research with any animal requires reflecting upon the ethical considerations of its use. The general rules for humane use of animals in research are known as the “Three Rs”: Replacement, Reduction and Refinement (Goldberg, Zurlo & Rudacille, 1996; Russell, 2005). Replacement refers to the use of alternative research methods such as the use of tissues, computer models, or human volunteers (Goldberg et al., 1996). Reduction

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is defined as using the smallest number of animals necessary to obtain precise and accurate data (Russell, 2005). Refinement entails minimizing the pain, discomfort and distress of animals used in research (Russell, 2005). Working with non-human primates adds another dimension to the ethical debate, as many believe that we should not work with animals that are “so human.” Some groups believe that apes should be protected with the same rights and freedoms as humans (Cavalieri and Singer, 1993). Because apes are morphologically, genetically and physiologically similar to humans, we need to be aware of how they are treated, and how we use them for our own ends. As apes also share similar psychological traits with humans, their environmental, social and mental welfare needs are often greater than those of a . However, drawing an ethical line at a certain species, or because of a certain mental capability, as grounds for exception or inclusion in medical research is questionable. Because of the aforementioned similarities of apes, many would like to exclude them from medical research. However exclusion based on species, or on possession of a certain mental capability presents a greater dilemma than simply focusing on the welfare of all animals in research. For instance, 14- month old human infants understand the concept of referential pointing. This is the ability to look where a person is pointing, and to locate an intended target based on the pointing gesture (Povinelli, Reaux, Bierschwale, Allain & Simm, 1997). All primates, including great apes, are poor at understanding referential pointing (Hare & Tomasello, 2005; Povinelli et al., 1997). However this ability is robust in domesticated dogs (Hare & Tomasello, 2005). This is only one example of the futility of trying to tease out specific reasons to include or exclude particular animals in research. If an organism has the capacity to feel pain, to suffer anxiety or stress, and to feel frustration if its basic needs (food, water, rest) are not met, then focusing on the welfare of that organism is of crucial importance (Heitman, 2002). Treating one organism “better” than another may be counterproductive. Ensuring the greatest welfare for each species, and meeting that species’ specific needs, is of great importance, no matter the species. The more we understand and learn about each species, the better we can plan for their welfare. We are morally bound to do the least harm possible, and to care for them to the best of our ability. But if we consider the physiological and psychological requirements of each species, and provide for them accordingly, the ethical issues become somewhat less difficult.

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The current study involved working with a chimpanzee (Pan troglodytes). My interactions with, and studying of Booee were supervised by the sanctuary that cares for him. Interactions were approved by his keepers, the sanctuary veterinarian, and the sanctuary director. Our interactions were considered part of his environmental enrichment. Environmental enrichment is required by law (U. S. Department of Agriculture, Animal and Plant Health Inspection Service, 1999) in order to facilitate captive primates’ well-being. The attention and mental stimulation Booee was afforded by these interactions was especially important because he is housed in isolation (Young, 2003). Chimpanzees are a highly social species, and housing in social groups is usually recommended (Young, 2003). Because Booee carries an infectious disease, he cannot be housed in a social group, so increased personal attention is especially welcomed for him at the sanctuary. It was also always Booee’s choice of whether or not to participate in the research sessions. He was free to walk away at any time, and was always treated with the utmost of respect. Thus I believe that my research was beneficial to Booee; he seemed not only willing, but eager to participate, so there seems to be no ethical issue with my experiment. The legacy of medical experiments with chimpanzees is fraught with difficulty. The United States and Gabon are the only countries in the world that contifnues to conduct invasive medical research with chimpanzee subjects (Wadman, 2011). This research focuses on Hepatitis C, although the efficacy of using the chimpanzee as a model for this disease is disputed (Bettauer, 2009; Wadman, 2011). As of 2011, the population of chimpanzees in research laboratories (around 725 individuals) costs the National Institutes of Health over $12 million a year for their care (Wadman, 2011). Once chimpanzees “retire” from medical research, they are required by law to be housed at exotic animal sanctuaries (U. S. Department of Health and Health Services, National Institue of Health, 2000). Although the NIH provides grants for the care of their retired chimpanzees, private funds are still needed to care for these animals. Chimpanzees from individually sponsored studies have no monetary support for lifetime care (Wadman, 2011), which puts the financial burden on the sanctuaries that accept these animals. A chimpanzee’s lifespan is approximately 40 years in the wild, and can be 60 years or more in captivity. This leads to an expensive task that sanctuaries across the country will have to face. In 2011, a bill was introduced in the United States Congress to eliminate the use of chimpanzees in medical research (U. S. Congress, 2011).

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Whether the United States will decide to stop using chimpanzees in research in the near future remains to be seen. However, it is imperative in the immediate future that laboratories focus on treating all laboratory animals humanely and respectfully, and providing financial support for their lifetime care.

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APPENDIX A

BOOEE’S SIGN VOCABULARY

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1. baby 26. puppet 2. ball 27. pencil 3. bird 28. pipe 4. black 29. red 5. Booee 30. Roger 6. book 31. shoe 7. Bruno 32. string 8. brush 33. tickle 9. come 34. that 10. down 35. toothbrush 11. drink 36. tree 12. food 37. up 13. fruit 38. Washoe 14. gimme 39. white 15. go 40. you 16. hat 17. hurry 18. hurt 19. in 20. Jack 21. key 22. listen 23. look 24. me 25. more

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APPENDIX B

DESCRIPTIONS OF “OLD” AND “NEW” SIGNS

"Old Signs" "New Signs" Hand Hand Sign Location Action Sign Location Action Configuration Configuration

Open hand, Open, flat hand, index finger Draw fingers away HAT Top of head Place on top of head FEATHER Top of head palm down and thumb from head touching

Left hand flat Index finger of right Open hands, Draw each open hand KEY palm, facing to Waist hand brought to left GLOVE palms Waist up the other right. palm downward

Both hands Sides of closed fists Both hands “t” Flicked downward SHOE Waist TOY Waist closed fists brought together handshape twice

Both hands Closed fists closed fists, Sides of index Draw pinky finger with index STRING pinky finger of Waist SOCK Waist fingers rubbed away from left fist fingers right hand against one another extended extended

Closed fist, Tips of closed Finger placed below Tips of fingers touch LOOK index finger Face FLOWER fingers Face eye each side of nose extended touching

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APPENDIX C

EXAMPLE OF DATA SHEET

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Data Sheet: 03 Date: ______Time: ______Weather: ______Session #: ______Cage: ______Booee’s Temperament: ______A B C D 1 Key String Shoe HAT 2 Look Key HAT String 3 SHOE Key Look Hat 4 String LOOK Hat Shoe 5 Key Hat Look STRING 6 Shoe HAT Look String 7 KEY Look Hat Shoe 8 String Hat SHOE Look 9 Key STRING Shoe Look 10 Hat String Key SHOE 11 LOOK Hat String Shoe 12 Key Hat STRING Look 13 Shoe HAT Key Look 14 String Key LOOK Shoe 15 Hat Shoe Look KEY 16 STRING Look Hat Shoe 17 KEY Hat Look String 18 Shoe STRING Look Key 19 Hat Look Shoe KEY 20 String Hat KEY Shoe

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End Time: ______Notes: ______