Experimental Evidence

1. Experimental Evidence • Rats drink little saccharin water at first but increase over time. • Loud tones (110 db) produce different responses depending on the background noise (60 vs 80 db). • Habituation occurred at 60 db • Sensitization occurred at 80 db • A loud background is arousing, leading to greater reactivity, not less.

2. Conditions Producing Change • More intense (stronger) stimuli produce stronger sensitization, less likely to produce habituation. • Greater sensitization and habituation occur when the stimulus is repeated frequently. • Changes in the stimulus prevent habituation. • Turkeys respond to shape changes.

3. Conditions (Cont.) • Sensitization can occur to many kinds of stimuli but habituation occurs only with innate responses. • Habituation and sensitization are transient (go away after seconds or minutes between stimuli). • Except long-term habituation. • Dishabituation – response returns when a sensitizing stimulus occurs.

4. Opponent-Process Theory • An explanation for addictions. • All experiences produce an affective reaction (pleasant or unpleasant) – called the A state. • This reaction gives rise to its opposite – called the B state. • B state is less intense and lasts longer. • Over time, the A state diminishes and the B state increases.

5. The Addiction Process • Tolerance – diminished A state. • Withdrawal – increased B state. • Addictive behavior is a coping response to the change in B state. • People try to enhance A state to offset the unpleasantness of the B state. • Without withdrawal symptoms there is no addictive behavior. • Time prevents B state strengthening.

6. What Sustains Addiction? • The B state is a non-specific aversive feeling. • Anything similarly aversive will motivate the addictive behavior, even if it has no relation to the substance. • Daily life stress produces a B state that results in behavior to create an A state. • Parachute jumpers – create a B state in order to feel the A state.

7. PSY402Theories of Learning Chapter 3

8. Political Classical Conditioning

9. Examples of Conditioning • Popcorn at the movies. • Fear of flying -- stronger with more turbulence (a stronger UCS). • An antelope shying away from low tree branches. • Nausea at the smell of alcohol after a hangover.

10. Conditioned Emotional Responses • Fear is an anticipatory pain response based on past experience. • Fear is conditioned whenever a CS is associated with an aversive (painful or negative) event. • Fear motivates two responses: • Escape (when pain is present) • Avoidance (when pain is imminent)

11. Conditioning Situations • Sign-tracking (autoshaping) – animals must recognize signs of food (UCS) and respond (UCR). • Pigeons pecking at key. • UCR, not an operant response, because behavior is specific to the stimulus. • Eyeblink conditioning • UCR is rapid, CR is slow. • Many trials are needed (100 pairings)

12. Fear conditioning • Avoidance is not a good measure of fear. • Suppression of an operant behavior occurs with a feared stimulus. • First – an operant behavior is learned. • Second – a CS is paired with an aversive UCS. • Third – the CS is presented in the operant chamber.

13. Suppression Ratio During CS SuppressionRatio = During CS + Without CS • The amount of time during and without the CS is equal. • The more fear, the lower the suppression ratio. • Ratios typically fall between 0 and .5

14. Flavor Aversion Learning • Garcia – rats will not drink water with saccharin if they get ill after drinking. • Significant avoidance occurs after just one trial. • Human food aversions are related to illness (89%). • Even if illness occurs hours later it is linked to the previous meal. • Not cognitive – know food not to blame

15. Conditions Affecting Acquisition Chapter 3, pages 48-69

16. Conditioning Paradigms • Delayed conditioning – the CS onset precedes the UCS onset. • Trace conditioning – the CS starts and ends before the UCS onset. • Simultaneous conditioning – the CS and UCS occur together. • Backward conditioning – the UCS starts and ends before the CS onset.

17. Temporal Conditioning • No CS is presented. • The UCS occurs at regular intervals. • A CR eventually occurs just before the UCS. • Mechanism: a biological state typically provides the CS. • Waking up just before the alarm goes off.

18. Importance of Timing • A cue (CS) needs to be a good predictor of the UCS. • Optimal inter-stimulus-interval (ISI) varies with the kind of response. • The latency to respond is different for different reflexes (saliva, heart rate) • Too long or too short intervals result in weaker conditioning. • Intermediate CS’s form a bridge.

19. Importance of CS Strength • CS intensity affects CR strength only when the CS intensity varies. • If the CS strength is always the same, then the CS strength doesn’t affect the size of the CR. • Both dogs must bite in order for their size to matter. • In order for CS intensity to matter, it must signal something.

20. Importance of UCS Strength • Strength of the CR increases with strength of the UCS. • The more intense the air puff, the stronger the eyeblink CR.

21. Salience of the CS • Salience refers to how noticeable a stimulus is – how likely an organism is to notice it in the environment. • Preparedness (evolutionary predisposition) makes some CS more salient than others. • The more salient the CS, the stronger the CR and faster learning.

22. Predictiveness of the CS • Predictiveness refers to how reliably the CS is associated with the UCS. • When two or more CS’s are present, only the most reliable elicits a CR. • When the CS occurs with the UCS more often than the UCS occurs alone, conditioning occurs. • A CS alone weakens conditioning.

23. Blocking • Presence of a previously conditioned CS (existing predictive cue) prevents conditioning of a new CS. • Parent threats – presence of fear of the parent prevents acquisition of fear to another stimulus.

24. Implications for Parenting • Threats (CS) should reliably be accompanied by punishment (UCS) or they will be ignored. • Timing of threat (CS) and punishment (UCS) should be close together – not wait until Dad gets home. • Fear of parents (CER) may block conditioning of any other CS.