lecture 24 - anya hurlbert Flashcards
declarative memory can be episodic or semantic.
episodic:
events we have experienced
semantic:
facts
visual association area:
Inferotemporal cortex (IT)
where is it located?
on the ventral (underneath) surface of the brain
discovery of cells in the IT cortex that respond specifically to…
faces
recordings in monkeys shows that there are cells that get excited when the monkeys eyes were presented with a particular face
the cells have selectivity for…
a particular viewpoint of the face (e.g side profile)
in IT there are particular cells who have increased activity in response to an intact face but not when the face is…
disarranged
face selective cells
when presented with 4 new faces the cell initially responds the same to all four
over repeated presentations it becomes specialised for faces 1 and 2
different cells will become specialised for different faces
face selective area in humans
OFA: occipital face area
FFA: fusiform face area
STS: superior temporal sulcus
fusiform face area is very specific for…
faces
occipital face area is specific for…
faces and bodies
STF is specific for
faces and bodies but faces more
prosopagnosia (face blindness)
causes:
stroke
trauma
degenerative disease
genetic
pre/post natal brain damage
two main types:
apperceptive: failure to encode the facial percept (unable to recognise a thing as a face)
associative: cannot recall faces of familiar people (cant put a name to the face)
the lesion has been localised to the…
FFA
prefrontal cortex takes in information across all the senses and is responsible for…
carrying out our higher order behaviours
the role of prefrontal cortex in working memory
multiple areas in prefrontal cortex are activated during delay period in a working memory task
prefrontal lesions cause deficits in…
complex problem solving
complex planning
complex maze tracing
remembering episodic memories and semantic memory intact
remembering sources of information
the medial temporal lobe areas (rhinal cortical areas, hippocampus)
evidence from experimental lesions in monkey
effect of bilateral temporal lobectomy in monkeys caused ‘psychic blindness’ (good visual perception but poor visual recognition i.e they do not understand what they see)
also caused flattened emotions
and hyperphagia (eating everything, didnt recognise what was food)
modern studies: delayed non match to sample task
the monkey is trained to lift up an object covering a well in order to find food underneath it
learns to associate the covered well with the food reward
after the monkey is trained it is presented with an extra well with a different object on it
the food is now under the new object and the monkey has to learn that
this requires…
recognition memory because it has to remember what the old sample was and then he has to be able to discriminate the new sample from the old sample in order to get reward
after lesioning the medial temporal cortex…
monkey performs worse on the task if the delay between seeing the old sample and then presented with new sample is too long
this task isolates declarative memory from procedural memory
procedural memory - motor skill (turn over the object)
declarative memory - which is the old and which is the new sample
(the declarative memory is damaged)
which is the key structure involved
the rhinal cortex (perirhinal)
hippocampus
rey figure test
copy and then reproduce from memory
after lesion in hippocampi, patient can copy but unable to reproduce from memory
his ability to form visual memories was impaired because of a loss of…
of neurones in the CA1 area of the hippocampus
the hippocampus in working memory
the radial maze:
an animal is trained to find pieces of food in the arms of the maze
the animal is put into the central cylinder and can run down each arm
an animal with a hippocampal lesion will repeatedly go down the same arms not remembering which one its been down to get the food (deficit in working memory)
these animals can remember which of the arms never have food as this information never changes, is it stored in consolidated procedural memory, not effected by lesion
hippocampal cells have place fields
these place cells respond when rat is in particular spatial location
it is likely that these cells play a role in memorising which arms have already been visited in the maze
cell 1 fires when the animal is in a certain location in the upper box, whether the partition is removed or not.
cell 2 develops a place field specific to the lower box only after 10 min of the animals exploration in larger space
new spatial memory formed in hippocampus
summary
cortical association areas
store permanently e.g face cells in IT or episodic memories
parahippocampal and rhinal cortical areas
consolidation of memory
lesion causes anterograde amnesia
hippocampus
spatial memory
relate into from different senses (e.g odor and location)
thalamus and hypothalamus (diencephalon)
part of limbic system
