Transcript Power Point 11

Emotional Memory
Conditioned Contextual fear
a variation of classical conditioning
A type of implicit memory
Any meaningless stimulus associated with a fearful
stimulus creates fear; therefore the context becomes a
cause for fear
In the context of the unconditioned stimulus event
This signals potentially dangerous situations
The autonomic system jumps in & produces increases in
blood pressure, breathing, & heart rate
Does it go away?
Extinction does occur after repeated presentations of
the UCS with no UR
However, there is “spontaneous recovery” of the
conditioned responses under stress
The Amygdala’s Role in Emotional Memory
If the amydala is removed in monkeys:
• lost terror of previously feared objects
• didn’t avoid noxious stimuli
• ate inappropriate objects
• tried to copulate with other species
• no fear conditioning
• no contextual fear conditioning if hippocampus function is
also impaired
What about in humans (with no amydala)?
Fear is lost but other emotions too as well as recognition
of emotional expressions through the face or voice
Double Dissociation through a study by Damasio et al.
SS saw a set of colour slides
When the blue slide appeared a loud boat horn sounding, producing
an increased GSR (Galvanic Skin Response)
Normal Ss were conditioned such that the blue color slide now produced
and increased GSR
Other Ss
Damaged hippocampus = increased GSR, no recall of episode
Damaged amygdala = recall of episode, no GSR
Damaged hippocampus + damaged amygdala – no recall & no increase in GSR
Amydala -- The 911 (999 if in the UK) of the human mind
A short cut from the thalamus (a way station of the
sensory systems)
Every major area of the brain
Triggers flight or fight hormones
Fixes the face in a fearful expression
Mobilizes the centers for movement
Increases blood flow to the muscles
Enhanced memory through emotional arousal
Study by McGaugh & Cahill
Group 1: story about a boy, riding a bicycle home,
& then is driven by his mother to the hospital to
pick up his father who works there as a doctor
Group 2: similar story but the boy is hit by a car &
rushed to the hospital
Recall better for Group 2 if no propranolol (blocks
noradrenaline); same with propranolol
Emotional Arousal Effects with Very Vivid Imagery
Within an Episodic Context:
• Flashbulb memories
• Earliest memories
• Post-Traumatic Stress Disorder
State Dependent Memory
Types of Studies:
Alcohol, drugs
Mood manipulation studies
Depressed patients
Note:These effects are typically small
Why do they occur
The key :
Associative neural networks in which each event is
represented by a cluster of units
To consciously recall the event, a threshold of
activation in the network has to be reached.
Activate one and the others are activated as well
eventually leading to activation of the cluster above
threshold.
Essential units have more weight in this process
Example
Sad mood registered in relation to an accident that
occurred in the fall at a friend’s house perhaps many
years ago
The network would include as component units
sad mood
the accident
the season
your friend
house location
A sad mood and the fall season might trigger enough
activation to bring into consciousness the original episode
Note: Mood is just one of the components that can help
trigger a memory!
There are also well known effects of place dependency
Study by Baddeley:with deep-sea divers
Learn memory list on-shore or underwater
Results:
Lists learned on-shore are better remembered on-shore
Lists learned underwater are better remember underwater
Can you think of any place dependent effects you have experienced?