• Difficult to define emotion and motivation in scientifically acceptable manner.
• Criteria--skeletal or autonomic response.
• Theories--many don't distinguish between subjective experience and behavior.

Anatomy of Emotion

• Hypothalamus -- Integration
  • Rage follows Dorsomedial nucleus stimulation
  • Partially integrated
  • Anterior and lateral hypothalamus, preoptic, septum, posterior hypothalamus are distinct systems--mediate flight, fight, attack (no pleasure)

• Limbic System -- Controlling mechanisms (unchanged from brain of lower animals)

  TOP

• Amygdala
  • Limbic system designed to frustrate experimental analysis
  • Fibers and Passage
  • Temporal lobe syndrome (Kluver&Bucy (37)
    • Compulsive oral response
    • Loss of fear, aggressiveness
    • Hypersexuality, increased activity
  • Conflicting results with lesion
    • Tame or wild
    • Territory (environment) is important factor (can't detect and react as at home)
    • Retard avoidance conditioning

• Hippocampus
  • Lesion--perseveration
    • Repetitive running, poor discrimination, and activity
    • Passive-avoidance deficit
    • Facilitate or impair active avoidance; depends on particular task
    • Isaacson (1961) greater resistance to extinction
    • Memory: Pribram--Penfield
    • Lesion control

• Septum
  • Lesion--emotional hypersensitivity (disappears with handling)
  • Impaired passive avoidance (not appetitive)
    • Increased exploration (errors) and exaggerated startle response

  TOP

• Olfactory projection fields (pyriform)

• Cingulate gyrus
  • Clinical--lesion for anxiety
  • Transient increase in emotionality but less response to stress.

• Thalamus
  • Clinical data - major area for emotion
  • Decortication sham rage not influenced by thalamic presence (removed by posterior hypothalamus)
  • Role difficult to assess because of many nuclei.

• Cortex -- Integration, direction
  • Removal--sham rage (stimulus bound) to neutral stimuli
  • Mediates stimuli and directs attack.
  • Required for pleasure.
  • Temporal Lobe
  • Frontal Lobe
    • Projections from hypothalamus
    • Lesion--impair delayed response.
    • Lobotomy--remove anxiety (intellectual deficit)
      • More restricted--good results
      • Orbital gyri--for chronic depression

• Brain Stem
  • Regulates individual responses that contribute to complete emotional reaction.
  • Rage to stimulation of higher areas doesn't occur after brainstem lesion.
  • Activation in emotion.
  • Connections with posterior hypothalamus.

Anatomical Connections

• Septum
  • Stria Terminalis
• Amygdala

  Papez Circuit

• Hippocampus
  • Fornix
• Mammillary Bodies (Posterior hypothalamus)
  • Mammalothalamic tract
• Anterior Thalamic Nuclei - DTPS
• Cingulate Gyrus (Neocortex)
• Presbicium -- connects with Hippocampus