Sensitization & Emotions and Motivated Behavior

Sensitization & Emotions and Motivated Behavior

1. Sensitization

   • Definition: Increase in the intensity or probability of an orienting response
     • Examples
       • Badley, Moulder & Lang, 2005
         • Pleasant or unpleasant pictures used to signal shock threat. How previous affective associations modulate new defensive reactions. When cuing threat of shock, pleasant and unpleasant pictures prompted physiological profiles consistent with defensive activation, indicating that threat of shock renders previously pleasant cues aversive. For unpleasant pictures only, defensive startle was potentiated even when these cues signaled safety. Taken together, the data indicate that (a) regardless of their intrinsic affective meaning, cues signaling shock threat prompt somatic and autonomic reactions consistent with defense, and that (b) intrinsically unpleasant cues continue to prompt defensive activation even when the context of their presentation is specifically nonthreatening.
       • Frost, Brandon, and Mongeluzi, 1998
         • 3 cycle escape swim motor program of the Tintonia

2. Habituation

   • Decrease in an orienting response
     • When Habituation becomes problematic

3. Opponent Process Theory

   • Homeostasis
     • Baseline Responding or Set Points
       • corresponds to the mechanisms that maintain stability within the physiological systems and hold all the parameters of the organisms internal milieu within limits that allow an organism to survive
         • It implied originally that i) deviations from normal set points are automatically corrected by local negative feedbacks, and ii) bodily organs are considered as functioning autonomously. Subsequently, homeostasis has been described as a self-regulating process for maintaining body parameters around a set point critical for survival (
           • This includes multi-system coordination of the organism's response to an acute challenge, including the brain, pituitary, autonomic system, and skeleto-motor systems. However, while some of the parameters of the internal milieu are held constant (like body temperature), other parameters like stress hormones are varied within a wide range in an attempt to maintain homeostasis.
   • Biphasic
     • Primary Process
       • DEF
     • Opponent Process
       • DEF
   • Allostatic
     • allostasis proposes maintenance of stability outside of the normal homeostatic range, where an organism must vary all the parameters of its physiological systems to match them appropriately to chronic demands
       • ). Allostasis refers to the integrative adaptive processes maintaining stability through change, a stability that is not within the normal homeostatic range. It implies that many, if not all, physiological functions are mobilized or suppressed, as reflected in a cascade of brain-organism interactions overriding local regulation. By controlling all the mechanisms simultaneously, the brain can enforce its command and introduce experience, memories, anticipation and re-evaluation of needs in anticipation of physiological requirements. The allostatic model, because it involves the whole brain and body instead of simply local feedbacks, is far more complex than homeostasis. All parameters of a given domain (e.g., blood pressure, or in the central nervous system reward function) are controlled by numerous mutually interacting signals. When demands become chronic, the brain-body system tonically adapts at essentially all levels of organization implying widespread changes in set points, and en

4. Habituation is to a decrease in the orienting response; as sensitization is to an increase in the orienting response.

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