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Space and Memory A two-way street
Example #2: memory in synapses
Memory-related processes involve spatial sensory/motor pathways
Example #1 Memory in activity Example #2 Memory in synapses Example #3 Parietal cortex Example #4 Hippocampus
Example #2 Memory in synapses Information can also be stored via changes in
synaptic efficacy Often occurs in (spatial) sensory/motor
pathways
Model system: Vestibulo-ocular reflex
Counter-rotation of the eyes when the head turns Serves to keep visual image stable on retina Must be calibrated
Head
Eye No change in retinal image
Head
Eye No change in retinal image
These turns must be matched!
Gain of VOR
Gain = Eye turn Head turn
E.g. desired gain = 1 if: -- Looking at something far away (head and eye rotate about different axes) -- Not wearing glasses!
Glasses change size of visual scene
VOR gain must be adjusted when you get new glasses
Changes occur within pathway that senses the head turn and moves the eye
Notably: Vestibular nuclei Cerebellum
Cerebellum Vestibular nuclei (inside brainstem)
VOR gain must be adjusted when you get new glasses
Changes occur within pathway that senses the head turn and moves the eye
Notably: Vestibular nuclei Cerebellum
Synapses Changes in the gain of the VOR are thought to be accomplished by changes in the strength of synapses
and are implemented in vestibular-oculomotor pathway
Next Up:
A two-way street Example #3: space and memory in parietal cortex