Chapter 2 The Study of Learning and Behaviour

Science is a Way of Thinking • • • Understanding the natural, physical world Asking questions Systematically seeking answers Observation Evidence-based research

Basic Assumptions of Science 1. A true, physical universe exists 2. The universe is primarily an orderly system 3. The principles of the orderly universe can be discovered 4. All knowledge is tentative

Natural Science Approach to Psychology • • All behaviour is caused Causes precede their effects O natural phenomena Parsimony: the simplest explanation that fits the data is best

Methods of Acquiring Knowledge Scientific empiricism Empiricism Rationalism (Logic) Authority Intuition Tenacity

Scientific Research Involves • • Pose a question How to answer it? Empirical observations (data collection) Data analysis

Science of Behaviour • Circular explanations Q: why did the chicken cross the road? A: to get to the other side. Q: how do we know the chicken wanted to get to the other side of the road? A: because it crossed the road. • Focus on physical events that elicit behaviour

Hard Line Behaviorism • John B. Watson • Psychology as “serious” science • Only use observable events

Facts and Inferences • Most facts observed in psychology are behaviours • We infer the internal condition from facts • Constructs: ideas formed from inferences

Learning • • • A change in behaviour Experience Acquisition of new behaviour Loss of old behaviour Observable behaviour change = a fact

Behaviour • Anything an agent does that can be measured Experience • Events that affect or have potential to affect behaviour • Stimulus – Physical event (internal or external to body)

Behaviour Change and Learning • • Not all change due to learning Maturation Fatigue Medication Evolution Injury Etc.

Measuring Learning • • Measure changes in behaviour Reduction in errors Change in topography Change in intensity Change in speed Change in latency Change in rate or frequency

Operational Definitions • Precise way of defining events • Multiple observers can agree on occurrence of event • Can be variation in behaviour • Interobserver reliability

Learning Curve – Humans/non-humans – Habituation, classical, operant, observational • Commonly shown in textbooks Responses/speed/ errors/etc. • Across situations Time/trials

Subjects Averages 4 Sample Size 2 1 1 2 Trials 3 4 Errors 1&2 3 Subjects 1 -5 1& 1, 2& 2, 23 & 3 4 Errors 3 2 1 4 3 4 Errors 2 Errors 4 3 2 Maze study with rats 2 Errors across trials 3 Trials 3 4 2 1 Trials 1, 2, 3 & 4 4 1 4 Errors 4 1 Errors 2 3 3 1 1 2 Trials 1, 2 & 3 4 Errors 1 Trials 2 1 4 4 1 3 3 3 2 1 1 1 2 Trials 3 4 1 Trials 1 -5 4 Errors 3 2 1 1 2 Trials 3 4 1 2 Trials

Levels of Constraint • Precision vs. flexibility – Sacrifice • How much constraint? – Highest possible, given the questions being asked

Study Designs • • • Anecdotal evidence Naturalistic observations Case-study Descriptive Experimental research Low constraint High constraint

Anecdotal Evidence • First or second hand reports • Personal experience • Unidentified factors

Naturalistic Observations • • Observe subjects in natural setting Minimum interference Limited controls Semi-naturalistic

Case Study • • Individual or small group Detailed analysis Time consuming Representative sample?

Descriptive • Often questionnaires, interviews, preexisting data, simple data collection, etc. • Often, but not always, uses – Descriptive statistics (e. g. , mean, st. dev. ) – Correlational statistics: positive, negative, none • Statistical analysis usually (but not always) seen for large data sets

Experimental Research • • • Manipulate one or more variables Measure effect Independent and dependent variables High control Artificial environment? Simplistic dependent variable (i. e. , behaviour)?

Between-Subjects Designs • 2+ groups of subjects • Independent variable different across groups • Dependent variable differences due to exposure to different independent variables • Representative sample • Matched sampling

Within-Subject Design • Each subject observed in different conditions • Baseline and treatment phases • ABAB design • Independent variable varies within the subject • Each subject both control & experimental “group”

Variables • Variable: Any set of events that may have different values • Behavioural variables • Stimulus variables • Subject variables • Independent variables • Dependent variables • Constants

Validity and Reliability • Validity – How well a study, a procedure, or a measure does what it is supposed to do. • Reliability – How well a measure can be reproduced – Replicability

Hypotheses • Hypothesis: A statement about relationships among variables that implies empirical testability • Applied to a study or elements of a study • A “mini-theory”

Theories • Theory: A formalized set of concepts that organizes observations and inferences, and predicts and explains phenomena • Applied to a collection of data derived from many studies • Testable • Theories can only be disproved

Judging Scientific Theories • • • Testability/falsifiability Simplicity Generality Fruitfulness Agreement with the data

Evaluating Research • Replication – Reliability – Conflicting results • Sampling bias – Sample: collection of subjects selected for a study – Population: much larger collection of animals or people from which the sample was drawn

Evaluating Research • Distortions in self-reports – Self-reports: subjects give a verbal/written account of their own performance • Demand characteristics • Experimental bias – Intentional and unintentional

Evaluating Research • Single-, double-, and triple-blind procedures • Placebo effects – – Mithoefer & Mithoefer (2010) Chronic therapy resistant PTSD; crime, war Two exposure therapy sessions; MDMA or placebo Two months later: PTSD in <17% MDMA subjects vs. 75% placebo subjects – Exposure therapy requires emotional engagement; hypothesize PTSD narrows patients’ “window” for engagement; MDMA may “widen the window” allowing them to stay engaged while revisiting traumatic experiences

Models • Representations of reality – Analogies • Need not be real – Make accurate predictions • New ideas generated from models B 1 R 1 = B 1+B 2 R 1+R 2

Animal Research • • Comparative psychology Models for human behaviour Simplified systems; more easily controlled Considerations: ethical, relevance of features, appropriateness

Issues • • • Differences between species Knowledge of species Theoretical vs. practical value Ethical use of animals Computer simulations