lecture seven
the morris water maze
A common test of spatial memory. A rodent is placed in a small round pool filled with opaque-colored water and must remember the location of a submerged platform to escape.
patient na
A patient who is unable to encode new declarative memories, because of damage to the dorsomedial thalamus and the mammillary bodies. - has diencephalic amnesia
comparison of memory and iq scores
IQ ok but memory impaired
patient rb
Largely confirms the role of the hippocampus in anterograde amnesia. He had an ischemic event during surgery that resulted in lesions to CA1 pyramidal cells in hippocampus. Led to anterograde amnesia and retrograde of 1-2 years.
Wernicke-Korsakoff syndrome
Organic brain syndrome resulting from prolonged heavy alcohol use, involving confusion, unintelligible speech, and loss of motor coordination. It may be caused by a deficiency of thiamine, a vitamin metabolized poorly by heavy drinkers. - produces similar memory deficits to those from temporal lobe damage
what kind of study was taxi study
cross sectional study with two groups at the same time
what is affected in wenicke kosakoff syndrome
dorsomedial nucleus of thalamus and mamillary bodies
how do we represent our location in space
egocentrically or allocentrically
allocentric
frame of reference is the external world eg south to the tree
longitudinal study of posterior hippocampal in taxi drivers
increased posterior hippocampus
Extended Hippocampal-Diencephalic Memory System
info from hippocampus to mamillary body to thalamus to rest of neo cortex - remote memories gone to neocortex are consolidated and remain in memory but those still in hippocampus are lost
what does hm show
iq improved which shows disscoiaten between iq and intelligence shows that hippocampus, medial temporal lobe are involved in memory consolidation shows dissociation of declarative memory from working and procedular memory
patient rb on rey osterreith figure
look at figure then draw it then after delay draw it again - draw it right away to see if it is motor or perceptual problem
longitudinal study
look at one group to see what chnages
hm memory loss
lost declarative memory with antereograde and retrograde amnesia still had procedural memory eg skills
what causes lack of thiamine
many heavy drinkers have poor nutrition and alcohol can inflame stomach lining and impede vitamin absorption
issues with taxi study
maybe other reasons for increased posterior size so compared to bus drivers who do similar things except bus drivers follow pre selected route you dont have to navigate - taxi drivers have larger posterior, bus drivers have larger anterior taxi drivers also better at recognising landmarks and saying time taken to destinations but poorer on copying test
damage to hippocampus with morris water test
put rat in different positions to find the platform eg variable start / allocentric or constrant start / egocentric control rats have no problem either way, rats with damage starting in egocentric still learn it but with allocentric dont learn
hpc + rhinal damage
rey ossterieth figure - cant rememeber at all or draw something random
taxi drivers and hippocampus
taxi drivers do a lot of spatial learning and show increased posterior hippocampal volume and is area involved in spatial learning - anterior hippocampus went smaller
what did they remove in hm
temporal lobe temporal pole hippocampus
egocentric
the frame of reference is the individual eg left of me
