PSY402 Theories of Learning

1. PSY402Theories of Learning Wednesday March 5, 2003

2. Expectancies • Expectancy –mental representation of event contingencies. • Dickinson – an expectancy contains two kinds of information: • Associative link between two events – classically conditioned, mechanistic. • Behavior-reinforcer belief – consequences of action, operant, intentional.

3. Testing Associative Links • Two groups trained to bar press: • One group reinforced with sodium (Na) • Other group reinforced with potassium (K) • Both tested when deprived of sodium. • Irrelevant incentive effect – sodium deprivation activated associative link for Na rats but not K rats. • Could be due to beliefs not links.

4. Testing for Beliefs • Reinforcer devaluation effect – what happens if reinforcer is diminished in value after training? • One group got sucrose for bar-pressing and food regardless of behavior. • Other group got food for bar-pressing and sucrose non-contingently. • Sucrose devalued during testing. • Bar pressing was lower when the sucrose was behavior-contingent.

5. Importance of Disgust • Devaluation is a two-stage process: • A disgust reaction is associated with the reinforcer (devalued by illness). • The reinforcer must be reexperienced. • Devaluation of the reinforcer occurs when reexperience activates the associated disgust. • Studied using ondansetron – a strong anti-emetic (reduces nausea).

6. Importance of Habits • Dickinson acknowledged that habits do exist and can control behavior. • Expectancies (behavior-reinforcer beliefs) control actions before habits are established. • Behavioral autonomy – control of responding by habit rather than expectancy. • Habit responds to devalued reinforcer.

7. Learned Helplessness Theory • Seligman – depression is learned. • Depression occurs when people believe: • Failures are due to uncontrollable events. • Failure will continue as long as events are beyond their control. • Depression arises from helplessness.

8. Animal Research • Step 1 -- three groups of dogs: • Inescapable shock – no control. • Escapable shock -- terminated if the dog pressed a panel. • No shock • Step 2 – 10 trials of signaled avoidance training in shuttle box. • 2/3 of inescapable shock dogs did not learn to jump during step 2.

9. Helplessness in Humans • Hiroto – three groups of college students: • Uncontrollable group – wrongly told that pushing button would end noise. • Escapable group – pushing button ended noise. • Control – no noise. • Tested using finger shuttle box. • Uncontrollable group did not escape

10. Characteristics of Helplessness • Motivational impairment – unable to initiate voluntary behavior. • Mice in water maze. • Nonspecific – carries over to a variety tasks and test situations. • Intellectual impairment – incapable of benefiting from future experience – even if they jump, don’t learn. • Emotional trauma – neg. affect.

11. Studies of Depressives • Show similar results to learned helplessness studies. • Depressed individuals do not escape noise, responding like inescapable non-depressed individuals. • Depressed individuals do not adjust likelihood of succeeding upward when they experience success. • They credit chance not skill.

12. Criticisms of Seligman’s Theory • There is more to depression than learned helplessness. • Helplessness subjects described the task as a skill task, even though acting as if it were a chance task. • Failure to replicate performance deficits in humans – facilitation of performance instead. • May be due to attributions.

13. Attribution Theory • Causal attributions of failure have three dimensions: • Internal-external – internal traits or characteristics vs environmental forces • Stable-unstable – past causes will persist vs new forces will determine future outcomes • Global-specific – outcome relates only to one task vs outcome effects everything.

14. Two Kinds of Helplessness • Personal helplessness – an individual’s inability causes failure. • Universal helplessness – the environment is structured so that no one can control future events. • Abramson -- both kinds lead to depression. • Vary on external-internal dimension. • Low self-esteem only with personal.