What is Psychology? Goal of Experimental Psychologists. Danger of calling yourself a Psychologist. Danger of calling yourself a Psychologist

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1 Danger of calling yourself a Psychologist Danger of calling yourself a Psychologist Scientific Psychology bears little resemblance to pop psychology, fortune telling, phrenology, or astrology Subjective, no scientific base Psychology is not just a fancy name for common sense Psychological research often produces findings that contradict popular beliefs Objective data collection Subjective data collection Systematic observation Hit or miss observation Reliance on evidence Ignoring counterevidence Goal of Experimental Psychologists Goals of psychology include: description of behaviour using careful observations explanation identifying the cause(s) of behaviour prediction allows for specification of the conditions under which a behaviour will or will not occur What is Psychology? Psychology is the science of brain (mental) processes and behaviour (Behaviour is an emergent property of the brain) Psychology values: critical thinking empirical evidence systematic research methods 1

2 Psychology as a Science Critical Thinking The ability and willingness to assess claims and make objective judgments on the basis of wellsupported reasons and evidence, rather than anecdote Define your terms Examine the evidence Consider other interpretations Psychology as a Science Hypothesis A statement that attempts to predict or to account for a set of phenomena Specifies relationships among events or variables and are empirically tested The predictions should be specific enough to expose the hypothesis to disconfirmation (falsifiability) Predict what will happen But also what will not happen Characteristics of Good Theories General Incorporating existing facts and observations within a single framework (broad explanatory power) Testable generate hypotheses that can be tested. Verifiable through direct observation (Falsifiable) Tentative Skeptical attitude, questioning possible problems with method or design and questioning assumptions, inferences, deductions Parsimonious the simplest theory (with fewest assumptions) is preferred How to judge Theories Experiments Rigorous methods Highly controlled to determine cause and effect Should be repeatable within and between laboratories Data Quality Ability to predict Ability to explain Ability to control 2

3 Why is it difficult to investigate learning & memory? People have little conscious awareness of mental processes thought to be beyond objective, scientific study because of its hidden character investigated with indirect methods On the basis of observations make inferences Scientific Inference When study learning often do not make direct observation of the processes involved Not a problem because ALL science must make careful inferences of the unobservable, based on logic, and data from observable events Experimental Variables To test a hypothesis, an experimenter defines the variables of the hypothesis: Cause: Independent variable (IV) What you manipulate Observable Effect: Dependent variable (DV) What you measure to test your hypothesis Observable Intervening variable unobservable process that helps explain relationship between IV and DV Not observable Extraneous variable what you (try to) control Experimental Observation Change value of one variable (the IV) while all other variables (noise) stay the same Observe whether there is a change in response measure (the DV) General procedure: Random assignment Different treatment Compare groups Controls important for determining causality the only difference is the presence or absence of the IV 3

4 The Scientific Method Research Questions Hypotheses Study Design Scientific Inference If DV depends on IV, then causation can be logically inferred Observation of variables Relationship among variables Conclusion from Research Intervening Variable Operational Definition Independent Variable ( Cause ) Hours since last meal Intervening variable Hunger Dependent Variable ( Effect ) Amount of food eaten Some variables are concrete and observable (e.g., kissing); others are abstract (e.g., love) Objectively observable event represents the occurrence of some internal, subjective event Hours without water Thirst Amount of water drunk Clearly defined set of procedures for obtaining a measure of the construct of interest Time devoted to study Learning Score on exam Procedure is specified precisely enough to allow replication by others 4

5 Operational Definition Objective measure Measurable behaviour Capture the essence of the concept or construct of interest Are there bad operational definitions? E.g., define height as the number of times that participants hit their heads when entering the testing area Between-Subject Design Independent group Random assignment Matched group Control of extraneous variables that may obscure effect of IV Matched on relevant characteristic Within-Subject Design More powerful design Repeated measures Control over error variance APA Ethical Guidelines (humans) informed consent awareness of risks confidentiality deception can be used ONLY if benefits justify it and there is no other way to do the study 5

6 APA Ethical Guidelines (animals) Researchers must ensure appropriate consideration of [the animal s] comfort, health, and humane treatment Animals may not be subjected to pain or stress when an alternative procedure is available Strict rules concerning housing and care Animal care and use committees Include a lay person Reviewed for scientific merit Reviewed to ensure all current animal welfare guidelines have been met General-Process Approach Adopted by animal learning researchers (chemist and physicists too!) Explain the greatest variance of observable phenomena with the smallest number of general laws Formulate laws to organize and explain a diversity of events Learning phenomena are products of elemental processes that operate consistently across situations Evidence that principles of learning have considerable generality in diverse species (especially vertebrates) Different levels of analysis Level of Analysis Learning Mechanism Area of Psychology Whole organism Neural circuits Neurochemicals Neurons Behavioural Neural systems Neural networks Molecular Cellular Development Cognition Clinical Physiological Psychology Behavioural Neuroscience Basic Neuroscience Learning & Memory How experience changes an organism Learning Perspective process of adaptation of behavior to experience EVENT Change in Behavior Memory (Cognitive) Perspective the permanent records that underlie this adaptation EVENT Change in what organism knows 6

7 Learning-Performance Problem The only way we can study learning is by observing performance, but. Performance does not always reflect learning! The Brain Changes its Functioning in Response to Experience Learning how experience changes the brain Memory how changes are stored and subsequently reactivated What brain structures are involved in processes of learning and memory? Effects of Bilateral Medial Temporal Lobectomy H.M. an epileptic who had his temporal lobes removed in 1953 His seizures were dramatically reduced but so was his ability to form new memories Mild retrograde amnesia and severe anterograde amnesia Retrograde (backward-acting) unable to remember the past Anterograde (forward-acting) unable to form new memories While H.M. is unable to form most types of new long-term memories, his STM is intact Assessing H.M. Digit span H.M. can repeat digits as long as the time between learning and recall is within the limits of short-term storage Mirror-drawing task H.M. exhibits improvement with practice. He is able to show skill memory demonstrating that he can learn some things (also rotary-pursuit and a drawing task) although he is not aware of it H.M. readily learns responses through Pavlovian (classical) and operant conditioning H.M. can learn some things, but has no memory of having learned them 7

8 Scientific Contributions of H.M. s Case Parallel learning systems Medial temporal lobes are involved in memory Short-term memory (STM) and long-term memory (LTM) are distinctly separate H.M. is unable to move memories from STM to LTM, a problem with memory consolidation Memory may exist but not be recalled as when H.M. exhibits a skill he does not know he has learned H.M. forms new implicit memories, but not new explicit memories conscious declarative HIPPOCAMPUS TEMPORAL LOBE knowledges adaptive behaviour extinguishable Time course: mutual inhibitory unconscious non-declarative BASAL GANGLIA skills, motor and cognitive rule like behaviour = habits not-extinguishable conscious incrementally acquired habit control associations The switch from spatial working memory (place learning) to habit learning (response learning) day 1-7 day 8... Goal start go to place start habit:go left Principles of Learning place learners Hippocampus response learners Basal ganglia 8

9 Who needs to know about the principles of learning? Cognitive Psychology Behavioural Neuroscience Physiological Psychology Developmental Psychology Clinical Psychology Diversity in Definitions of Learning You may want to learn all of the facts in this text Acquisition of readily available knowledge I want to learn about the neural mechanisms of learning Discovery of previously unknown information All parents want their children to learn good manners Change behaviour patterns Some people may want to learn how to play tennis Acquire new behaviour and new knowledge What is learning? NOT What is learning? NOT Students do not have a monopoly on learning NOT specific to classroom NOT specific to age NOT specific to humans As a psychological concept NOT correctness of response NOT deliberate attempts to remember NOT referring just to observable responses 9

10 Common Definitions of Learning A relatively permanent change in the ability to exhibit a behaviour (knowledge) as the result of experience Enduring change in the way an organism responds based on it experience Enduring change in the mechanisms of behaviour involving specific stimuli and/or responses that results from prior experience with those stimuli and responses Learning Learning allows us to: To use past experience to predict the future To adapt to a rapidly changing environment To exert control over our environment Behaviour is what changes when learning occurs Behaviour, in science, anything the organism does that can be measured What is learning? Because learning examines causes that alter behaviour through prior experience And causes cannot be observed directly Learning must involve inferring causality from the results of your experimental manipulations What is learning? Psychologists are interested in: Process Events that change behaviour Product Long-term changes in behaviour 10

11 What is learning? E.g., Raccoons and Trashcans Process (Acquisition phase) Period in which animal is acquiring a new skill Organized plan of action or haphazard luck What factors determine duration in face of obstacles? Product (Performance of learned behaviour) How will intermittent success influence frequency of behaviour? Will the behaviour generalize? Learning Three assumptions of learning theories Responses are learned rather than innate Learning is adaptive Experiments can uncover the laws of learning and these laws will apply to: Different species Different situations Different behaviours Learning Experience (nurture) is the key to learning a relatively permanent change in behaviour brought about by experience distinguishes between maturation and experience distinguishes between short-term changes in performance and actual learning Learning Learning is inferred from behaviour, but isn t behaviour (intervening variable) Some things look like learning that are not learning Just because change in performance cannot be automatically considered to reflect learning Temporary, physical states, e.g., Fatigue Change in physiological or motivational state Maturation Drugs 11

12 Any of these represent learning? Why use Animals? An infant who stops thumb-sucking? Children being able to use language? A patient who has a lobotomy and no longer manifests psychotic behaviour? A plant being pinched back and then growing more dense foliage and flowers? Harry throwing his cigarettes away after 30 years of smoking two packs a day? A computer that uses its first 100 tabulations to influence its choice of opening moves in a chess game? Human behaviour is incredibly complex, thus animals serve as a model to understand behavioural complexity Simpler System Animals used to identify basic components of learning Principles of Learning Developed from animal research Why use Animals? Why use Animals? Evolutionary continuity of the brain and nervous system Necessary for theoretical and methodological reasons Information about the physiology of learning processes Ethical considerations may prevent the use of human subjects in experimental situations Animal models allow investigations to be simpler, better controlled Validity of animal models depends on the similarity between the animal model and human behaviour in relevant features of the behaviour being studied Experimental Control Reliable! Always show up to experiments Minimize the placebo effect not motivated to behave a certain way due to preconceptions Food & water how much, when, where, what kind Light cycles length of day Temperature Past history: genetic and socialization 12

13 Why use NOT Animals? Difficult to address complex human functions Language, reading, problem solving Ethics Even though very strict ethical guides, are the scientific advances worth it? Why use Animals? Preverbal Humans Infants do not talk so are not able to tell us what they see or hear Must develop methods to assess what they are learning Latent Learning In the 1930 s, Tolman s Maze Study Rats were allowed to explore a maze without a food reward while two other groups were trained using a reward Food rats quickly learn to follow the correct path (they run to the end) Non-food rats just wander around Day 11 one group of non-food rats were given food at the end of the maze Latent Learning After only 1 or 2 rewarded trials, these rats were shown to do as well as rats that had been trained with rewards Rats in the third group learned about the layout of the maze while they were just wandering around no behavioural evidence of this learning until the situation changes (i.e., motivated to get to a particular part of the maze quickly) I.e., the rats had formed some kind of a map of the maze! LATENT LEARNING 13

14 Tolman s Study on Latent Learning Take Home Message Many species, including humans, rely on learning for survival Although most people pay more attention to acquiring new behaviours, learning not respond is just as important as learning to make new responses (Figure adapted from Tolman & Honzik, 1930, p. 267) Diversity of Learning Learning can result from special instructional training (classes) and from common contacts with the environment 14