7 Memory and the Temporal Lobe Flashcards
What was Karl Lashley’s principle of “mass action’?
That memory is distributed throughout the cortex
Who was patient H.M?
- Concussed at 9
- Suffered severe seizures did not respond to medication.
- Had a temporal lobotomy (hippocampus removed)
- Severe anterograde amnesia
- Intact short term and remote memory
- did not recognised examiners for 50 years
- GOT BETTER AT SKILLS BUT COULD NOT REMEMBER –> SUGGESTS DIFFERENT AREAS FOR MEMORY
Long-Term Memory can be split into…
Declarative (Explicit) memory
Nondeclartive (Implicit) Memory
What is Declarative Memory?
- Facts
- Events
–> Related to Medial temporal lobe
What is non declarative (implicit) memory?
- Procedural (skills and habits)
- Priming
- Simple classical conditioning
- Nonassociative learning
areas: striatum, neocortex, amygdala, cerebellum, reflex pathways
H.Ms deficits show…
- Dissociation of intelligence and memory
- Dissociation of declarative memory from working procedural memory
- The hippocampus is involved in memory consolidation.
What happens when you disrupt the hippocampal circut? (Patient R.B)
Selective, marked anterograde amnesia and very minor retrograde amnesia.
RB had compressed hippocampus with damage to CA and CA1
What is the Rey-Osterreith Figure and what does it suggest?
Copying task.
Damage to a small portion of the hippocampus produces a memory deficit.
What else was damaged in H.M’s brain?
Inner medial portion of temporal lobe is gone.
HPC
Rhinal Ctx
What do patients with HPC + Rhinal damage show in the Rey-Osterreith figure?
they couldn’t remember anything
What is Wernicke-Korsakoff Syndrome?
Sydrome that occurs in heavy drinkers, produces similar memory deficits to those that result from temporal lobe damage
Cause by a lack of thiamine (vitamin B1)
Memory is poor and IQ is poor
What does the hippocampal-diencephalic memory system suggest?
Need to complete the hippocampal circuit to form a memory.
New and recent memories depend on the hippocampus diencephalic
This suggests overtime you don’t need this system, therefore explaining why damage to this system produces anterograde and retrograde amnesia.
Two ways we can represent our location in space…
Egocentric: the frame of reference is the individual e.g. left/right, in front of me. (Reference to self)
Allocentric: The frame of refernce is the external world e.g. north, south, to the east of the tree. between the tree and the house (reference to the external world like a building)
What do rats with hippocampal damage display in the water maze?
They can find “the hidden playform when having an egocentric start. But are unable too when using variable start cues.
What region in taxi drivers brains changed when learning the many roads of london?
Increased posterior hippocampal volume in taxi drivers compared to controls.
Internal got smaller, but medial part got bigger.
Time spent as taxi driver correlates with hippocampal volume
What does the longitudinal study of posterior hippocampal grey matter in taxi drivers tell us?
The change is best examined with longitudinal studies
it is the experience of taxi driving that changes the size of the hippocampus
What is a place cell in the hippocampal?
A place cell is a kind of pyramidal neuron in the hippocampus that becomes active when an animal enters a particular place in its environment, which is known as the place field. Place cells are thought to act collectively as a cognitive representation of a specific location in space, known as a cognitive map.
This pattern of activity could be incorporated into a memory representation and so may underlie the ‘where’ of episodic memory. Instantiating the ‘where’ of episodic memory.
