Limbic System & Memory
Limbic System
• Located above the brainstem, beneath the
cerebral cortex
• Involved in emotions such as fear, anger,
pleasure
• Also plays a role in memory
Hippocampus
• In Medial Temporal Lobe, sea horse
shape
• Major cortex center
• Involved in forming new memories
• Declarative memories, not procedural
(skills)
• Also detection of surroundings
Hypothalamus
• Regulates hunger, thirst, body temp control,
response to pain, levels of pleasure, sexual
satisfaction, anger and aggression
• Regulates ANS
• Connected to Pituitary Gland:
regulates many hormones
Amygdala
• Amygdala: in Medial Temporal Lobe
– Involved in stimulus response: fear, aggression,
sexual responses
– When stimulated here, animals respond with
aggression
Memory
• There is NO single center in the brain that
stores memories
• Long-term memories are stored throughout
the brain as groups of neurons that are
primed to fire together in the same pattern
• Groups of neurons in the visual cortex store a
sight, neurons in the amygdala store the
associated emotion
Memory
• Different types of memories are processed
differently
• Olfactory bulb and cortex are physically very
close to hippocampus and amygdala
– Smells usually initiate best sensory memory
Memory
• Consolidation: when short term memories are
“moved” to become independent of
hippocampus
– Synapses increase in number and strength as
number of signals increases (1000s per neuron)
– With increased frequency of a group of neurons
firing together, it’s easier to repeat this pattern
– Future neural messages more likely to follow this
path of least resistance
• Consolidation is time-dependent
• Sleep =important in improving the
consolidation of memories
• Activation patterns in the sleeping brain
mirror those from the previous day
Memory
• Short term: information in use right now
– Follow 7 +/- Rule
• Long term: those short term memories that
are rehearsed and concentrated switch to
“long-term”
Short Term Memory Test
• 1st: Listen to the following list of words...
• THEN when I say “GO” write down as many as
you remember
Amnesia
• Retrograde Amnesia: Impaired ability to recall
past events and previously familiar info
• Anterograde Amnesia: Impaired ability to
learn new information (declarative memories)
Youtube: Clive Wearing
“Patient HM”
• Henry Gustav Molaison: 1953
• Surgery to remove part of Temporal Medial
Lobe: Hippocampus & Amygdala
• Post surgery: suffered severe amnesia (some
of both types)
– Could improve motor skills, though he didn’t
remember practicing them
Youtube: Clive Wearing
Homework:
• Research and write a paragraph:
– How does emotion affect our memories?
– Are there any studies or examples of specific
memories that were altered due to an emotional
response to the event?
Memory
• False memory
• Eyewitness accounts
• Emotion affects memory?
• New memory test: listen to the list and then
write down as many words as you remember.
Discussion questions:
• How does emotion affect memory?
• What are false and reconstructive memories?
• Add to your homework paragraph to turn in
Photo 1
Photo 2
Distractions
2×4+8–2÷2+3×3=
5! = 5 x 4 x 3 x 2 x 1 = 120
30
Photo 1
•
•
•
•
What was the child in front wearing?
Describe the man in the front.
Describe the background?
Where there people, desert, sky, or traffic in
the background?
Photo 1
Photo 2
• Describe the people in the photo: how many
were there?
• What were they wearing?
• What surface were they walking on?
• What was in the background?
• What was on the right side of the screen?
Photo 2
Homework question discussion
• How does emotion affect memory?
• Are there any studies or examples of specific
memories that were altered due to an emotional
response to the event?
• Reconstructive memories
– All memories are reconstructed by brain- it’s not
like watching a video
– Brain fills in the blanks
– Example via Ted Talk: 9/11
– The brain abhors a vacuum
– Retell a story you heard: War of Ghosts