TB8 Flashcards
What part of the brain did HM have removed?
the medial temporal lobe
What deficits did HM have?
no memory since the operation= dense anterograde amnesia, ate lunch the same time in a row, watched films many times in a row
What is anterograde amnesia?
From the brain injury to present
What is retrograde amnesia?
From birth until the brain injury
What effect did anoxia, carbon monoxide poisoning have on RB’s brain?
Damage to the hippocampus
What brain damage does herpes encephalitis cause?
Damage to the hippocampus and ATC
What damage to the brain does Korsakoff’s syndrome cause?
damage to maxillary bodies
What three structures are associated with amnesia?
Hippocampus, fornix and mammillary bodies
What do the mammillary bodies connect?
Connect the fornix and thalamus
What is the effect of amnesia on verbal learning?
Dense amnesiacs have problems completing verbal learning tasks and patients with mild amnesia has slight impairments on verbal learning
What functions are preserved in amnesia?
STM, semantic memory, implicit (non-conscious memory)
What is the stem completion task and how did amnesiacs perform?
Stem task involves presenting the first part of the word and hiding the rest in order to get the participant to guess the word. When they were told nothing about the words, they performed better than controls but when told the words were related to previous words, they performed worse.
What is the hippocampus responsible for?
Conscious retrieval of a recent exposure or episode/episodic memory
What area of the brain is activated when a familiar character is seen?
Anterior Temporal lobe
What is memory?
A series of processes where the nervous system acquires information from new experiences, retains information and guides behaviour.
What animal is the hippocampus named after?
Seahorse
Where does the hippocampus receive information from?
The entorinal cortex, parahippocampal cortex and perihinal cortex
What is the function of the perihinal cortex?
Object recognition
What is the function of the posterior hippocampus? And where does it receive this information from?
Spacial orientation - parahippocampal cortex
What is the function of the anterior hippocampus?
And where does it receive this information from?
Emotion and object recognition - amygdala and perihinal cortex
Where does the information come from into the hippocampus and how does it exit?
Inputs enter by the debate gyrus and exits by the subiculum
What is an example of the presynaptic cell?
CA3
Explain the response of a weak response of LTP
Weak response = small amount of glutamate is released into the synapse, AMPA (a receptor) allows NA+tions to diffuse into the post-synaptic neurone, causing slight depolarisation but not enough for MG blocking the NMDA receptor to be moved. NO action potential
Explain the response of a strong stimulus
Causes lots of Na+ neurones to go through AMPA (a receptor) into the post synaptic neurone. This LARGE depolarisation causes the Mg+ ion to be displaced and so Na+ and Ca+ ions enter through NMDA and cause an action potential. This causes more AMPA neurones to be connected to the post synaptic membrane so that next time there will be a greater influx of Na+ neurones and this strengthens the communication of that synapse
What drug blocks the NMDA receptor?
Ketamine
Which brain area has the most NMDA receptors?
The hippocampus