DOCSLIB.ORG

Classical (Pavlovian) Conditioning

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Classical (Pavlovian) Conditioning Classical Conditioning Learning & Memory Arlo Clark-Foos What is classical conditioning? • Learning to associate previously neutral stimuli with the subsequent events. • Howard Eichenbaum’s Thanksgiving Pavlov’s psychic secretion Are you conditioned? • Some examples of every day conditioning… – Holiday Traditions – Food Associations – Fears – Superstitions – Habits – Skills? Ivan Pavlov • How are digestive fluids controlled? – Historical view – Pavlov’s view – Pavlov’s Original Experiment Pavlov’s Experiments • Psychic Secretion – Specialized procedure for introducing food • Claude Bernard’s psychic secretion in horses – Pavlov’s psychic secretion was unreliable but… Pavlov Museum, Ryazan, Russia Stimuli and Responses This is appetitive conditioning. What is an example of aversive conditioning? Conditioned Emotional Response Estes & Skinner Appetitive (Dudai, Jan, Byers, Quinn, & (Domjan, Lyons, North, & Benzer, 1976) Bruell, 1986) Slapping and Blinking in the Name of Research Ernest Hilgard Clark Hull Electromyography (EMG) Photo Sensors Very well studied Rabbit Eyeblink Conditioning reactive predictive It gets more complicated… • Similarity among species • Tolerance, compensatory responses, and homeostasis • Stimulus Timing and Presentation – Contemporaneous Presentation • Not spaced too far apart in time – Is there an ideal spacing? – Order and Consistency • Reliable relationship/expectation Conditioning Procedures Interstimulus Intertrial Interval Interval Forward Conditioning Learning Not to Respond Conditioned Inhibition: Decrease in CR in response to CS. – Need Baseline CRs diminish CS+1(Tone) US CS1 ? CS1 + CS2 over time as CS- CS-2(Light) CS2 ? inhibits CS+ Baseline Transfer of Learning • Generalization CS800mHz CR CS Max CR CS(Tone,1200mHz) US 1200mHz CS1600mHz CR • Discrimination CS(Tone,300mHz) CS300mHz CS(Tone,500mHz) US CS500mHz CR CS(Tone,800mHz) CS800mHz Context as CS • Penick & Solomon (1991) – Eyeblink conditioning in rats – Hippocampal Lesions Transfer Appropriate Processing & Encoding Specificity What is being conditioned? • How is it learned and what is the nature of the association? S-S or S-R Association? • Stimulus Substitution Theory (Pavlov) – Definition (S-R Association) – US, CS, and Response centers in the brain US Response S-S Association CS S-R Association – Problem: a CR is not a UR • CR eyeblink is often more gradual and less complete Rescorla (1973) US Devaluation Conditioned Suppression Habituate Noise Lever Reward Lever + Light? (Light/CS + Loud Noise/US) US Response S-S Less CR after US devaluation. Association CS S-R S-S Association Association After Conditioning • After learning, what happens when you present the CS alone? Extinction What happens in extinction? • What do we (researchers) see? – No CR = Forgetting? – Excitatory and Inhibitory Associations (Pavlov) • CC • Extinction Human eyeblink conditioning and the reduction in responses during extinction. Extinction = Forgetting? • Spontaneous Recovery – Pavlov: Inhibitory connections are weak, fade – Alt. Theory: Attention/Interest in CS (habituation?) Human eyeblink conditioning and the reduction in responses during extinction. Extinction = Forgetting? • Disinhibition – Surprising, typically arousing, new stimulus – Return of CR (akin to sensitization) • Rapid Reacquisition – Retraining vs. Original Conditioning – Something is retained Extinction is NOT Forgetting Compound Conditioning • Context, Multiple Cues – Extinction: “respond” and “don’t respond” • Overshadowing – Salience Error Correction • Problems with Aristotle’s contiguity • Informational value of cues • Kamin’s (1969) Compound conditioning Rescorla-Wagner (1972) • Learning on Trains – Contiguity is not enough • Competition for associative strength • Prediction Error – Positive vs. Negative prediction errors – Error-correction learning R-W in Humans • Error Correction in Human Category Learning – Bower & Trabasso, 1964 • Informational value of dot Modelling Conditioning • Associative Weights – Connectionist Models (e.g., McClelland & Rumelhart) Pay Attention! • Exposure to CS alone retards later learning – Attention to stimuli – Latent inhibition • Lubow & Moore (1959) – Sheep and Goats • Where is the surprise? – US Modulation Theory • Prediction error (Rescorla & Wagner, 1972) – CS Modulation Theory • Attention to stimuli (Mackintosh, 1975) Properties of C Conditioning • It takes time – 4-5 mo., no eyeblink conditioning in first block but exposure necessary for later learning. • Other Factors – Intensity of CS-US – Timing, ISI Ivkovich et al., 1999 Intensity of CS-US • Faster and More effective US Intensity Maintained US Intensity Decreased Timing, ISI • Timing is critical! – Ideal ISI for rapid learning – Humans = Animals Pavlov observed no CRs with Backward Conditioning: CS does not predict US. Animals must be learning association AND temporal contiguity Taste Aversion (Garcia Effect) • Temporal Contiguity – Food poisoning after a date… • Belongingness: CS-US pairings. – Tone + Food Shock or Poison – (Garcia & Koelling, 1966) • Neurological basis: gustatory cortex • Coyotes (Gustavson et al., 1974) Neural Basis in Mammals • Cerebellum – Purkinje cells • Inhibitory connection to interpositus nucleus – Interpositus nucleus • CR output pathway • Error correction • Brain Stem – Pontine nuclei (CS) • Specialized sensory processing – Inferior Olive (US) • Activates interpositus nucleus and Purkinje cells Neural Bases of CC A simpler diagram of Rabbit eyeblink conditioning Cerebellum • Electrical activity Purkinje cells • Stimulating the inferior olive – Even specific tones, lights, etc. – Substitute for actual US • CC impaired after damage CS Modulation • Latent inhibition not explained by RW • Mackintosh (1975) – Salience of Sensory cues – Hippocampus • Animals without do NOT show latent inhibition Back to Aplysia CC in Aplysia 1. Aplysia and Eric Kandel Neural Bases of CC In the long run, it’s all just LTP Proteins • Two routes to long lasting memory – Activate CREB-1 • Synaptic growth – Deactivate CREB-2 • Rapid learning Addiction and Tolerance • Homeostasis and compensatory responses – Environmental cues as CS • Reducing reliance on drugs? + +.
Load more

Recommended publications
  • Eric Kandel Form in Which This Information Is Stored
    RESEARCH I NEWS pendent, this system would be expected to [2] HEEsch and J E Bums. Distance estimation work quite well, since the new recruit bees by foraging honeybees, The Journal ofExperi­ mental Biology, Vo1.199, pp. 155-162, 1996. tend to take the same route as the experi­ [3] M V Srinivasan, S W Zhang, M Lehrer, and T enced scout bee. What dOJhe ants do when S Collett, Honeybee Navigation en route to they cover similarly several kilometres on the goal: Visual flight control and odometry, foot to look for food? Preliminary evidence The Journal ofExperimental Biology, Vol. 199, pp. 237-244, 1996. indicates that they don't use an odometer but [4] M V Srinivasan, S W Zhang, M Altwein, and instead might count steps! J Tautz, Honeybee Navigation: Nature and Calibration of the Odometer, Science, Vol. Suggested Reading 287, pp. 851-853, 1996. [1] Karl von Frisch, The dance language and OT­ Moushumi Sen Sarma, Centre for Ecological Sci­ ientation of bees, Harvard Univ. Press, Cam­ ences, Indian Institute of Science, Bangalore 560012, bridge, MA, USA, 1993. India. Email: [email protected] Learning from a Sea Snail: modify future behaviour, then memory is the Eric Kandel form in which this information is stored. Together, they represent one of the most valuable and powerful adaptations ever to Rohini Balakrishnan have evolved in nervous systems, for they In the year 2000, Eric Kandel shared the allow the future to access the past, conferring Nobel Prize in Physiology and Medicinel flexibility to behaviour and improving the with two other neurobiologists: Arvid chances of survival in unpredictable, rapidly Carlsson and Paul Greengard.
    [Show full text]
  • Introduction and Historical Perspective
    Chapter 1 Introduction and Historical Perspective “ Nothing in biology makes sense except in the light of evolution. ” modified by the developmental history of the organism, Theodosius Dobzhansky its physiology – from cellular to systems levels – and by the social and physical environment. Finally, behaviors are shaped through evolutionary forces of natural selection OVERVIEW that optimize survival and reproduction ( Figure 1.1 ). Truly, the study of behavior provides us with a window through Behavioral genetics aims to understand the genetic which we can view much of biology. mechanisms that enable the nervous system to direct Understanding behaviors requires a multidisciplinary appropriate interactions between organisms and their perspective, with regulation of gene expression at its core. social and physical environments. Early scientific The emerging field of behavioral genetics is still taking explorations of animal behavior defined the fields shape and its boundaries are still being defined. Behavioral of experimental psychology and classical ethology. genetics has evolved through the merger of experimental Behavioral genetics has emerged as an interdisciplin- psychology and classical ethology with evolutionary biol- ary science at the interface of experimental psychology, ogy and genetics, and also incorporates aspects of neuro- classical ethology, genetics, and neuroscience. This science ( Figure 1.2 ). To gain a perspective on the current chapter provides a brief overview of the emergence of definition of this field, it is helpful
    [Show full text]
  • Consciousness Eclipsed: Jacques Loeb, Ivan P. Pavlov, and the Rise of Reductionistic Biology After 1900
    Consciousness and Cognition Consciousness and Cognition 14 (2005) 219–230 www.elsevier.com/locate/concog Consciousness eclipsed: Jacques Loeb, Ivan P. Pavlov, and the rise of reductionistic biology after 1900 Ralph J. Greenspan*, Bernard J. Baars The Neurosciences Institute, 10640 John Jay Hopkins Dr., San Diego, CA 92121, United States Received 17 May 2004 Available online 25 November 2004 Abstract The life sciences in the 20th century were guided to a large extent by a reductionist program seeking to explain biological phenomena in terms of physics and chemistry. Two scientists who figured prominently in the establishment and dissemination of this program were Jacques Loeb in biology and Ivan P. Pavlov in psychological behaviorism. While neither succeeded in accounting for higher mental functions in physical- chemical terms, both adopted positions that reduced the problem of consciousness to the level of reflexes and associations. The intellectual origins of this view and the impediment to the study of consciousness as an object of inquiry in its own right that it may have imposed on peers, students, and those who followed is explored. Ó 2004 Elsevier Inc. All rights reserved. Keywords: History of ideas; Reductionism; Tropism; Conditional reflex 1. Introduction The current acceptance of consciousness as a suitable object of study in the life sciences came late in the 20th century (Flanagan, 1984). By that time other biological processes—physiology, biochemistry, genetics, embryology, and even many aspects of brain function—had long since * Corresponding author. Fax: +1 858 626 2099. E-mail addresses: [email protected] (R.J. Greenspan), [email protected] (B.J.
    [Show full text]
  • The Fessard's School of Neurophysiology After
    The fessard’s School of neurophysiology after the Second World War in france: globalisation and diversity in neurophysiological research (1938-1955) Jean-Gaël Barbara To cite this version: Jean-Gaël Barbara. The fessard’s School of neurophysiology after the Second World War in france: globalisation and diversity in neurophysiological research (1938-1955). Archives Italiennes de Biologie, Universita degli Studi di Pisa, 2011. halshs-03090650 HAL Id: halshs-03090650 https://halshs.archives-ouvertes.fr/halshs-03090650 Submitted on 11 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The Fessard’s School of neurophysiology after the Second World War in France: globalization and diversity in neurophysiological research (1938-1955) Jean- Gaël Barbara Université Pierre et Marie Curie, Paris, Centre National de la Recherche Scientifique, CNRS UMR 7102 Université Denis Diderot, Paris, Centre National de la Recherche Scientifique, CNRS UMR 7219 [email protected] Postal Address : JG Barbara, UPMC, case 14, 7 quai Saint Bernard, 75005,
    [Show full text]
  • Cells of the Nervous System
    3/23/2015 Nervous Systems | Principles of Biology from Nature Education contents Principles of Biology 126 Nervous Systems A flock of Canada geese use auditory and visual cues to maintain a V­ formation in flight. How are these animals able to respond so quickly to environmental cues? All animals possess neurons, cells that form a complex network capable of transmitting and receiving signals. This neural network forms the nervous system. The nervous system coordinates the movement and internal physiology of an organism, as well as its decision­making and behavior. In all but the simplest animals, neurons are bundled into nerves that facilitate signal transmission. More complex animals have a central nervous system (CNS) that includes the brain and nerve cords. Vertebrates also have a peripheral nervous system (PNS) that transmits signals between the body and the CNS. Cells of the Nervous System Structure of the neuron. Figure 1 shows the general structure of a neuron. The organelles and nucleus of a neuron are contained in a large central structure called the cell body, or soma. Most nerve cells also have multiple dendrites in addition to the cell body. Dendrites are short, branched extensions that receive signals from other neurons. Each neuron also has a single axon, a long extension that transmits signals to other cells. The point of attachment of the axon to the cell body is called the axon hillock. The other end of the axon is usually branched, and each branch ends in a synaptic terminal. The synaptic terminal forms a synapse, or junction, with another cell.
    [Show full text]
  • Kandel and Hawkins
    © 1992 SCIENTIFIC AMERICAN, INC The Biological Basis of Learnin and Individuality Recent discoveries suggestg that learning engages a simple set of rules that modify the strength of connections between neurons in the brain. These changes play an important role in making each individual unique by Eric R. Kandel and Robert D. Hawkins ver the past several decades, there surgeon at the Montreal Neurological Institute. has been a gradual merger of two In the 1940s Penfield began to use electri­ originally separate fields of science: cal stimulation to map motor, sensory and neurobiology,O the science of the brain, and language functions in the cortex of patients cognitive psychology, the science of the mind. undergoing neurosurgery for the relief of Recently the pace of unification has quick­ epilepsy. Because the brain itself does not ened, with the result that a new intellectual have pain receptors, brain surgery can be car­ framework has emerged for examining percep­ ried out under local anesthesia in fully con­ tion, language, memory and conscious aware­ scious patients, who can describe what they ness. This new framework is based on the abil­ experience in response to electric stimuli ap­ ity to study the biological substrates of these plied to different cortical areas. Penfield ex­ mental functions. A particularly faSCinating plored the cortical surface in more than 1,000 example can be seen in the study of learning. Elementary as­ patients. Occasionally he found that electrical stimulation pects of the neuronal mechanisms important for several dif­ produced an experiential response, or flashback, in which ferent types of learning can now be studied on the cellular the patients described a coherent recollection of an earlier and even on the molecular level.
    [Show full text]
  • 1. Overview 2. Database Architecture 3. Example Tree 6. Mentorship Network Influences?
    Neurotree: Graphing the academic genealogy of neuroscience Stephen V. David1, Will Chertoff1, Titipat Achakulvisut2, Daniel Acuna2 1Oregon Health & Science University, 2Northwestern University 1. Overview 3. Example tree 4. Founding ancestors Neurotree (http://neurotree.org, [1]) is a collaborative, open-access Name N Resarch area Family tree The distance between two nodes can be Johannes Müller 7715 Physiology website that tracks and visualizes the academic genealogy and history P+ William Fitch measured by the number of mentorship Sir Charles Sherrington 4758 Neurophysiology of neuroscience. After 10 years of growth driven by user-generated Allen Hermann von Helmholtz 3048 Psychophysics University of P- steps connecting them through a Sir John Eccles 2998 Synapses content, the site has captured information about the mentorship of over Rudolf Oregon Ludwig Robert Samuel Alexander Sir Charles Medical common ancestor i(below). The list at Karl Lashley 2558 Learning and memory 80,000 neuroscientists. It has become a unique tool for a community of John Friedrich Karl Koch Sir Charles Kinnier Charles Gordon John Scott Sir Charles Harvey Sir Charles Karl Edgar School C+ Louis Agassiz 2241 Anatomy Sir Michael Newport Goltz Virchow Universität Scott Wilson Symonds Holmes Farquhar Sherrington Scott Williams Scott Spencer Wilder Douglas Frederic right shows the 30 most frequent primary researchers, students, journal editors, and the press. Once Foster Langley Kaiser-Wilhelms- Universität Berlin (ID Sherrington National Hospital, Queen National
    [Show full text]
  • Learning Learning and Reinforcement Simple Learning Habituation and Sensitization Classical Conditioning Classical Conditioning
    Learning Learning and reinforcement Learning A long-lasting change in behavior, or potential to change behavior, that results from experience Reinforcement Anything that affects the probability that a particular behavior will occur Simple learning Habituation and sensitization Aplysia Repeated presentation of stimulus chaffinch Habituation Sensitization Percent birds respondingbirds Percent Playbacks Eric Kandel Classical conditioning Classical conditioning Is there any adaptive significance of classical conditioning? food (US) salivation (UR) food (US) + tone (CS) salivation (UR) tone (CS) salivation (CR) Ivan Pavlov 1 Classical conditioning Classical conditioning ♂ ♀ blue gourami Karen Hollis Mount Holyoke Classical conditioning Classical conditioning How might classical conditioning work in nature? Courtship behavior by female (US) Courtship (UR) Courtship behavior by female (US) + sex-recognition cue (CS) Courtship (UR) Sex-recognition cue (CS) Courtship (CR) Japanese quail Heritability of conditioned response Gene × environment interactions Proboscis extension response conditioned to various odors Evidence of significant heritability Tryon Maze Dull and Bright rats Offspring score Offspring Parent score 2 Operant conditioning Laws of effect and exercise Thorndike Operant conditioning Operant conditioning Operant conditioning = association between Negative behavior and its consequences Positive reinforcement reinforcement Increase likelihood that behavior will occur B.F. Skinner Operant conditioning What factors affect conditioning?
    [Show full text]
  • The Fessard's School of Neurophysiology After the Second
    Archives Italiennes de Biologie, 149 (Suppl.): 187-195, 2011. The fessard’s School of neurophysiology after the Second World War in france: globalisation and diversity in neurophysiological research (1938-1955) J.-G. BARBARA Université Pierre et Marie Curie, Paris, Centre National de la Recherche Scientifique, CNRS UMR 7102; Université Denis Diderot, Paris, Centre National de la Recherche Scientifique, CNRS UMR 7219 ABSTRACT In France, neurophysiology emerged after the Second World War as a dynamic discipline in different schools, Toulouse, Lyons, Montpellier, Marseilles, and Paris, where Lapicque was losing credit with his studies on the excitability of nerves. Parisian neurophysiologist, Alfred Fessard (1900-1982) was a key figure in establishing a new school of neurophysiology on the model of Edgar Adrian’s department in Cambridge, where he worked for a few months in the late thirties. Fessard was initially a student of Henri Piéron involved in experimental psychology. He also made parallel oscillographic studies on elementary activities in various animal and plant preparations. His school trained leading French neurophysiologists in Paris until recently and Fessard was instrumental in the creation of IBRO in 1961. Key words Neurophysiology • France • Fessard • IBRO • Torpedo fish • Chemical neurotransmission After the Second World War, major French figures Marey suggested the creation of an International in neurophysiology emerged from different tradi- Commission for the control of graphical instruments tions in Toulouse, Lyons Montpellier, Strasburg, devoted to physiology. A new cottage named Institut Marseilles, and Paris. Alfred Fessard (1900-1982) is Marey was built near the Physiological Station recognized today as a most talented neurophysiolo- Marey had planned for his studies on movement in gist in the 1940s and 1950s who was able to create Boulogne-Billancourt, Le Parc des Princes, near his own school near Paris, in the former Institut Paris.
    [Show full text]
  • Psychopathology-Madjirova.Pdf
    NADEJDA PETROVA MADJIROVA PSYCHOPATHOLOGY psychophysiological and clinical aspects PLOVDIV 2005 I devote this book to all my patients that shared with me their intimate problems. © Nadejda Petrova Madjirova, 2015 PSYCHOPATHOLOGY: PSYCHOPHYSIOLOGICAL AND CLINICAL ASPECTS Prof. Dr. Nadejda Petrova Madjirova, MD, PhD, DMSs Reviewer: Prof. Rumen Ivandv Stamatov, PhD, DPS Prof. Drozdstoj Stoyanov Stoyanov, PhD, MD Design: Nadejda P. Madjirova, MD, PhD, DMSc. Prepress: Galya Gerasimova Printed by ISBN I. COMMON ASPECTS IN PSYCHOPHYSIOLOGY “A wise man ought to realize that health is his most valuable possession” Hippocrates C O N T E N T S I. Common aspects in psychophysiology. ..................................................1 1. Some aspects on brain structure. ....................................................5 2. Lateralisation of the brain hemispheres. ..........................................7 II. Experimental Psychology. ..................................................................... 11 1. Ivan Petrovich Pavlov. .................................................................... 11 2. John Watson’s experiments with little Albert. .................................15 III. Psychic spheres. ...................................................................................20 1. Perception – disturbances..............................................................21 2. Disturbances of Will .......................................................................40 3. Emotions ........................................................................................49
    [Show full text]
  • Beyond Pavlov, Thorndike, and Skinner: Other Early Behaviorist Theories
    Supplementary reading in the Companion Website accompanying HUMAN LEARNING 5/E by J. E. Ormrod, 2008, Upper Saddle River, NJ: Merrill/Prentice Hall. Copyright© 2007 by Pearson Education, Inc. All rights reserved. BEYOND PAVLOV, THORNDIKE, AND SKINNER: OTHER EARLY BEHAVIORIST THEORIES Chapters 3 and 4 in Human Learning describe the work of three prominent early behaviorists: Ivan Pavlov, Edward Thorndike, and B. F. Skinner. But other theorists had a significant impact on early behaviorist thinking as well. Here we’ll focus on three especially notable ones: John Watson, Edwin Guthrie, and Clark Hull. John Watson It was actually John Watson (1913) who introduced the term behaviorism and served as the most vocal advocate for the behaviorist perspective in the early part of the twentieth century. In his major writings, Watson (1914, 1916, 1919, 1925) adamantly called for the introduction of scientific objectivity and experimentation into the study of psychological phenomena. He emphasized the need for focusing scientific inquiry on observable behaviors rather than on such nonobservable phenomena as “thinking.” Not only did Watson oppose the study of internal mental events, but he also denied any existence of the mind at all! Thought, he proposed, was nothing more than tiny movements of the tongue and larynx and thus was a behavior just like any other. Greatly influenced by the work of both Pavlov and another Russian, Vladimir Bechterev (1913), Watson adopted the classically conditioned S-R habit as the basic unit of learning and extended it to human learning (e.g., see Watson and Rayner’s study with an infant named Albert, described in Chapter 3).1 Watson proposed two laws describing how such habits develop.
    [Show full text]
  • Evolution by Natural Selection
    Approaches to studying animal behavior Foundations of modern study of behavior 1. Evolution by natural selection 2. Genetics and inheritance 3. Comparative method Evolution by natural selection Evolution by natural selection Species are not immutable Alfred Russell Wallace (1823-1913) Charles Darwin (1809-1882) Contributions to the Theory Origin of Species, 1859 of Natural Selection, 1870 Descent of Man, 1871 Thomas Malthus Descent from a common ancestor Evolution by natural selection Comparative method Reasons why Darwin‟s (and Wallace‟s) ideas weren‟t widely accepted: Comparative method: comparing traits and environments across taxa in search of correlations Lord Kelvin: Earth is only 15-20 million years old that test hypotheses about adaptation Darwin had no idea where genetic variability came from Thomas Hunt Morgan Darwin didn‟t George Romanes understand inheritance (1848-1894) Gregor Mendel 1 Ethology Ethology Scientific study of animal behavior Oskar Heinroth (1871-1945) Charles Otis Whitman (1842-1910) Appetitive behavior Wallace Craig (1876-1954) Douglas Spalding (1841-1877) tests the concept of instinct Consummatory behavior Rise of ethology Experimental ethology Karl von Frisch (1886-1982) Jakob von Uexkϋll (1864-1944) von Uexkϋll‟s tick and the Umwelt Ethology’s triumvirate Ethology’s triumvirate Konrad Lorenz Niko Tinbergen Karl von Frisch (1903-1989) (1907-1988) (1886-1982) 2 Sign stimuli Sign stimuli Lorenz‟s accidental discovery of sign stimuli or releasers Experimental ethology Experimental ethology Tinbergen‟s experiments
    [Show full text]