BEHAVIORISM.140

• Habituation


  A decrease in the strength of an elicited behavior following repeated presentations of the eliciting stimulus
• Sensitization


  An increase in the strength of an elicited behavior following repeated presentations of the eliciting stimulus
• Both habituation and sensitization usually disappear when the stimulus is not presented for a period of time
• Sensitization generalizes to other stimuli
• Habituation tends to be more stimulus specific
• Even small changes in the stimulus may result in reappearance of the response
• Evolutionary (adaptive) significance of the stimulus


  • Currently irrelevant - habituate
  • Currently relevant - not habituate
  • Extremely relevant/dangerous - sensitized
• Intensity of the eliciting stimulus

  • Low-intensity (e.g., ticking of the clock) - habituation
  • High-intensity (e.g., exploding artillery shells) - sensitization
  • Intermediate intensity (e.g., shots fired in a shooting range) - initial period of sensitization followed by habituation
• Dishabituation


  Reappearance of habituated responses following the presentation of a seemingly irrelevant novel stimulus
• Opponent-process theory of emotion

  • An emotional event elicits two competing processes:
  • An a-process (or primary process) that is directly elicited by the event
  • A b-process (or opponent process) elicited by the a-process and serves to counteract the a-process
  • Slow to increase and slow to decrease
  • With repeated presentations of the emotional event, the b-process increases in both strength and duration
• Classical conditioning


  A type of conditioned learning which occurs because of the subject's instinctive responses
• Respondent conditioning


  • The acquisition of knowledge in responding to environmental signals
  • A type of learning that happens when stimuli naturally produce a response
• Unconditioned stimulus (US)


  Stimulus that leads to an automatic response
• Unconditioned response (UR)


  Automatic response to a stimulus
• Conditioned stimulus (CS)


  Stimulus that can trigger a conditioned response
• Conditioned response (CR)


  Learned response to a previously neutral stimulus
• In classical conditioning, a conditioned response depends on an unconditioned stimulus for its existence
• Unconditioned stimulus is referred to as a reinforcer
• Recipe for classical conditioning

  1. To produce a CR, the CS and the US must be paired a number of times (conditioning trial)

  2. CS is first presented then the US

  3. Each time the US occurs, a UR occurs

  4. A CR is demonstrated when a response similar to UR is elicited even when CS is presented alone
• Pavlov believed that the CS comes to substitute for the US (stimulus substitute learning); thus, the UR and the CR are always the same kind of response
• However, the magnitude of CR is always less than the UR
• Later research suggests that Pavlov's contention that CRs are always a "mini-me" of URs is incorrect
• Excitatory conditioning (CS+)


  Conditioning in which the NS is associated with the presentation of a US; results in eliciting a certain response
• Inhibitory conditioning (CS-)


  Conditioning in which the NS is associated with the absence or removal of a US; the CS comes to inhibit the occurrence of a certain response
• Appetitive conditioning


  US is an event that is an organism will generally approach and seek out
• Aversive conditioning


  US is an event that an organism generally avoids
• Classical conditioning can transform a normally aversive stimulus into an appetitive stimulus
• Delay conditioning


  Often the best arrangement for conditioning especially if the ISI is relatively short
• Trace conditioning


  Can be almost as effective as delay conditioning if the trace interval is relatively short
• Simultaneous conditioning


  Usually results in poor conditioning (even if closest possible contiguity)
• Acquisition


  Process of developing and strengthening a CR through repeated pairings of a NS with a US
• Acquisition proceeds rapidly during early conditioning trials then gradually levels off
• More intense USs produce stronger and more rapid conditioning than do less intense USs
• More intense NSs result in stronger and more rapid conditioning than do less intense NSs
• Extinction


  • Repeated presentation of the CS in the absence of the US (procedure)
  • Process is the decrease in the strength of the CR
• Spontaneous recovery


  Reappearance of a CR when a period of extinction is followed by a rest period
• Spontaneous recovery is likely to happen when contexts are different and does not last forever</b>
• Stimulus generalization


  Tendency for a CR to occur in the presence of a stimulus that is similar to the CS
• Stimulus discrimination


  Tendency for a response to be elicited more by one stimulus than another
• Discrimination training and experimental neurosis: Shenger-Krestovnikova produced a disorder in which animals exposed to unpredictable events develop neurotic-like symptoms