Transcript BHS 499-07 Memory and Amnesia

BHS 499-07
Memory and Amnesia
Emotion and Memory
Complexities
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Emotion is both an experience to be
remembered and a mediator of memory.
Emotion affects recall and recognition in
opposite ways, and has different effects
on explicit and implicit memory.
• This is the same dissociation seen earlier.
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Emotion itself is a complex phenomena:
• Moods vs discrete emotions, what is emotion?
Classical Conditioning
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Classical conditioning involves a form of
memory because associations are
formed and used in the future.
Conditioning is strengthened by strong
emotion.
LeDoux decorticated rats and showed
that learning persisted but could not be
unlearned, so amygdala is essential.
LeDoux’s Two Roads
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High road goes from a stimulus to the
sensory thalamus to the sensory cortex
and then back to the amygdala.
• The cortex processes sensory information first
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Low road goes from the emotional
stimulus to the sensory thalamus and
then directly to the amygdala.
• No cortical involvement
Implications of Two Roads
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Subsequent learning can permit the
cortex access via the high road to
overrule the activation of the amygdala:
• Interpretation
• Unlearning
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When fast response is essential to
survival, the low road is very fast and
motivates an automatic response.
Amygdala as the Hub
Rhinal Cortex
(transition)
Memories
Sensory
Cortex
Amygdala
Sensory
Thalamus
Memories &
Context
Hippocampus
Medial
Prefrontal
Extinction
The Cortex Works Through the
Hippocampus
Visual
Cortex
Auditory
Cortex
Transition Cortex (perirhinal,
parahippocampal, entorhinal)
Hippocampus
Somatic
Cortex
Two Systems
Emotional Situation
Amygdala
System
Implicit Emotional Memory
Hippocampal
System
Explicit Memory About
Emotional Situation
Intersection of Two Systems
Immediate Conscious
Experience (working
memory)
Amygdala-dependent
emotional arousal (current)
Hippocampal-dependent explicit
memory (past emotions)
Role of Adrenaline
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Adrenaline is produced by stimulation of
the hypothalamus by the amydala.
Adrenaline forms stronger memories by
stimulating the hippocampus and
amygdala (as well as many other areas).
LTP is enhanced.
Mood-Dependent Memory
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Mood affect encoding (as described
earlier).
Later, mood affects recall as a statedependent or context effect.
• Mood-dependent recall requires strong
emotion and is most obvious in
autobiographical memory.
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Other memory phenomena contribute
(e.g., causal belonging & associations).
Memory About Emotion
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Includes the same semantic
organizational structures as other
categories.
• Basic, subordinate and superordinate levels.
• Fuzzy boundaries, prototypes.
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Schemas and scripts for the evoking and
expression of emotion (cultural).
Body Memory
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Body and other sense memory is an
example of classical conditioning.
The response is in the brain, not the
body, but evoked via sensory
stimulation.
Senses can evoke powerful “memories”
of past experiences through such
associations.
PTSD
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Includes repetition compulsion and
occurs as a dysfunctional response to
perceived threat.
Intrusive memories may be distortions
affected by an internal conflict or
concern.
“Triggering” is classical conditioning.