Running head: MODALITY EFFECTS IN THE MISINFORMATION PARADIGM 1 Modality Effects in False Memory Production Using the Misinformation Paradigm Megan Hendrich Marietta College A Thesis Submitted to the Faculty of Marietta College In Partial Fulfillment of the Requirements for the Degree of Master of Arts in Psychology MODALITY EFFECTS IN THE MISINFORMATION PARADIGM 3 Abstract Human memories are often prone to memory errors and distortions (Loftus, 2005; Straube, 2012). One commonly studied memory error is false memory, which refers to memories or details in memories that are fictitious or altered (Straube, 2012). Past research using the Deese- Roediger-McDermott (DRM) task (Roediger & McDermott, 1995) has found that the modalities—specifically visual or auditory—in which information is encoded and tested can affect rates of false memory (e.g., Smith & Hunt, 1998); however, little research has examined how modality effects may impact false memory in the misinformation paradigm. The current study examined the effects of visual and auditory modalities and encoding-misinformation modality mismatch on false memory using the misinformation paradigm. Participants completed the misinformation paradigm in visual and/or auditory modalities for the event encoding phase and misinformation phase, and then participants’ veridical memory rate, misinformation- consistent response rate, and false memory rate were examined. It was found that the misinformation modality had a significant effect on the veridical memory rate. Participants in the auditory misinformation modality had higher veridical memory scores than participants in the visual misinformation modality. It is suggested that hearing the auditory description of the event during the second phase of the misinformation paradigm may have strengthened participants’ memories of the unmanipulated information more than viewing the pictorial description strengthened participants’ memories. Keywords: false memory, misinformation paradigm, modality effects, visual and auditory MODALITY EFFECTS IN THE MISINFORMATION PARADIGM 4 Modality Effects in False Memory Production Using the Misinformation Paradigm Decades of research on memory has shown that human memories are prone to memory errors and distortions (Loftus, 2005; Loftus, Miller, & Burns, 1978; Straube, 2012). One commonly studied memory error is false memory, which refers to memories or details in memories that are fictitious or altered (Straube, 2012). The two main paradigms for studying false memory include the misinformation paradigm (Loftus et al., 1978) and the Deese-Roediger- McDermott (DRM) task (Roediger & McDermott, 1995). Research using the DRM task has found that the modalities—specifically visual or auditory—in which information is encoded and tested can affect rates of false memory (Gallo, McDermott, Percer, & Roediger, 2001; Olszewska, Reuter-Lorenz, Munier, & Bendler, 2015; Smith & Hunt, 1998); however, little research has examined how modality effects may impact false memory in the misinformation paradigm (Dijkstra & Moerman, 2012; Stark, Okado, & Loftus, 2010). The current study examined the effects of visual and auditory modalities and encoding-misinformation modality mismatch on false memory using the misinformation paradigm. False Memory Research False memory refers to the type of memory error that involves remembering events or details of events that did not actually happen (Straube, 2012). Declarative memories—memories that can be consciously recalled such as events and knowledge—are more prone to false memories than other memory systems, likely because declarative memories are flexible representations of the world, and their flexibility can lead to errors (Straube, 2012). Further, episodic memory—a subset of declarative memory that is characterized as memory for autobiographical events—is the most frequently researched aspect of false memory because it is considered most vulnerable to memory errors due to its constructive nature. This type of memory MODALITY EFFECTS IN THE MISINFORMATION PARADIGM 5 is constructive because it involves combining pieces of information so that one’s memories are more easily accessible and organized, and the new information is integrated with previous knowledge, attitudes, and beliefs (Schacter, 2012). The constructive nature of memory is seen as adaptive because it supports the processing of memories in a way that is useful and promotes efficient functioning. For example, combining and integrating new and old information allows people to develop and update schemas that help them understand how the world works and make judgments quickly. This can also lead to generalization and abstract thinking that can allow people to imagine future events, without experiencing them, based on past knowledge. However, this constructive process also often leads to memory errors and distortions. Due to this process, episodic memories are not perfect reflections of the world; they are highly influenced by factors such as prior knowledge and emotion (Straube, 2012). Therefore, even though people may be confident in their memories, their memories may be inaccurate representations of what actually occurred (Loftus, 2005). Some of the first research looking at false memory was performed by Loftus et al. (1978), where the researchers investigated how people’s memories of an event are affected after being provided with misinformation about the event. In this series of studies, the researchers presented participants with a series of pictures showing the progression of an auto-pedestrian accident. The critical pictures involved showing the car at the corner of an intersection (before the accident) with either a stop sign or a yield sign on the corner. The participants then completed a questionnaire in which the critical question asked if the car was passed by another car while at either a stop or yield sign. Half of the participants received consistent information (e.g., stop sign in picture and question), and half of the participants received inconsistent information (e.g., yield sign in picture and stop sign in question). After a filler activity, participants viewed pairs of MODALITY EFFECTS IN THE MISINFORMATION PARADIGM 6 pictures and were asked which one was in the original set of pictures. The critical pair of pictures showed the car stopped at either a stop sign or a yield sign. Overall, the experiments by Loftus et al. (1978) showed that the misleading information led people to have less accurate responses on the memory tests, and people believed that the misinformation was what they actually saw in the original pictures. The effect of misinformation is similar to the effect of retroactive interference, which occurs when new information interferes with the accuracy of past memories; however, the misinformation also biases the memory instead of just interfering with its accuracy (Loftus, 2005). Additionally, this series of experiments examined several factors related to the misinformation effect. First, the experiments showed that participants’ responses were not influenced by demand characteristics (e.g., if the participants noticed the different signs from the picture and question, guessed the experimental hypothesis, and then based their answer on that). Second, the participants had in fact seen the original sign (i.e., if they had not seen the original sign, the misinformation may have just added information where there was none previously). Finally, these experiments showed that performance on the memory test was poorer if the misleading information was presented after a delay in which the original memory may have been weakened. These studies—and further research on the topic— show that people integrate information from multiple sources into their memories, which can be detrimental in some cases because it may lead to incorrect or false memories. Further research using misinformation techniques has shown that people are able to recall completely false autobiographical events after receiving misleading information (Loftus & Pickrell, 1995). Loftus and Pickrell (1995) conducted the first “lost in the mall” study to show how false events could be implanted in people’s memories. After talking with family members of the participants, the researchers constructed a realistic false memory for each participant: getting MODALITY EFFECTS IN THE MISINFORMATION PARADIGM 7 lost in a mall or store at the age of five and being assisted by an elderly person. Throughout two interviews about the false event, a quarter of the participants indicated that they had at least a partial memory of the event; however, compared with their descriptions of true-life childhood events, the participants described the false events with less detail and less clarity. Interestingly, the researchers also found that some participants began to add their own details to the false memories by their last interview and were reluctant to believe that the memories were false. This study is one example of how entire false memories can be supplanted through suggestion. Other research studies have additionally shown that false memories can persist for a long time after the initial encoding (Lommen, Engelhard, & van den Hout, 2013; Zhu et al., 2012). For example, during interviews about stressful experiences during recent military deployment to Afghanistan, Lommen et al. (2013) suggested to soldiers a fictional event had occurred during deployment. All the soldiers initially stated that they had not experienced that event; however, seven months later,