Habituation and Sensitization Theories & Treatments

Groves and Thompson's Theory: Habituation and Sensitization

  • Mike Davies' experiment:
    • Examined the startle response to a 110 decibel tone in rats.
    • Two groups of rats received 100 presentations of the loud noise at 30-second intervals.
    • Groups differed in background noise levels:
      • Group 1: Quiet background noise (60 decibels, conversation level).
      • Group 2: Loud background noise (80 decibels, heavy traffic level).
    • Background noise manipulated arousal levels.

Experimental Results

  • Soft background noise:
    • Repetitions of loud noise resulted in a weaker startle response (habituation).
  • Loud background noise:
    • Repetitions of loud noise resulted in a stronger startle response (sensitization).

Groves and Thompson's Explanation

  • Low background noise:
    • Minimal activation of the state system.
    • Changes primarily due to stimulus-response connection activation, decreasing with repeated stimulation.
  • Loud background noise:
    • Animal is aroused.
    • Startle stimulus activated in the presence of an aroused state, leading to sensitization.

Habituation in Treating Psychological Disorders

  • Habituation of aberrant responses:
    • Used to change behavior (e.g., anxiety disorders).
    • Anxiety disorders involve extreme fear responses to specific stimuli.
  • Exposure-based treatments:
    • Involve exposing patients to feared stimuli.
    • Repeated exposures lead to habituation, reducing fear.
    • Most effective treatment for anxiety disorders.

Systematic Desensitization

  • Developed by Joseph Walpie in the late 1950s for specific phobias.
  • Procedure:
    • Gradual exposure to the phobic object.
    • Combined with relaxation exercises.
  • Hierarchy of fears:
    • Determined from least to most fear-inducing.
  • Example (spider phobia):
    • Least fear: Looking at a picture of a spider.
    • Progression: Looking at picture close-up, model spider, video of spider, someone holding a small spider, holding a small spider, looking at a big real spider, touching the spider.

Groves and Thompson's Explanation for Systematic Desensitization

  • Repeated exposure leads to a decrease in the stimulus-response pathway (spider-fear response).
  • Importance of relaxation:
    • Graded exposure is not essential, but relaxation during stimulus presentation is crucial.
    • Relaxation allows for habituation of the stimulus-response pathway.
  • Practical considerations:
    • Controlling arousal levels is necessary to encourage participation in therapy.
    • Facing the greatest fear immediately can increase arousal and reduce the likelihood of participation.

Real-World Relevance

  • Systematic desensitization applies habituation theories to treat psychological disorders, demonstrating the practical application of these learning principles.