Midterm 2 Flashcards
Henry Molaison (patient HM)
o Man who had his amygdala and HC removed. He developed a case of retrograde amnesia and was found to also have good nondeclarative memory after he did a series of mirror drawings and over time he remembered them even though he did not have recollection of knowing these drawings cerebellum shrunk too
Hippocampus
A medial temporal lobe structure that is important for learning and memory. Converts short term declarative memory into long term declarative memory
Study in Science: hippocampal neurogenesis and forgetting
o More neurogenesis the less likely you were to remember something (seen in infants). Experiement where mice were shocked and the ones with less neurogenesis remembered what happens at that setting (measure # of neurons).
Delayed non-matching-to-sample task
o Measure memory in monkeys by having them identify which object was not seen previously. They show the monkey a key and one other object and under the other object they hide a piece of food. They have a delay of 8-10 sec before they will let monkey choose which one had food. If damage to HC like HM this will be very hard.
Patient NA
Like HM but he had a sword put up nose and hit part of brain. He too had anterograde amnesia and a better nondeclarative memeory because of it. Had damage to Dorsomedial Thalamus and Mamilliary body both parts of HC.
• Dorsomedial thalamus (T)
limbic system structure connected to hypothalamus that has to do with memory decoding
Mammilary body (T)
limbic system connected to HC. It may serve as a processing system connecting HC and nearby cortex to thalamus to cortical sites
Korsakoff’s syndrome
o Degenerative disease with damage to the limbic system esp mammillary body and dorsomedial thalamus. They fail to recognize some objects they see repeatedly. They make up (confabulate) what things are by filling in the blanks with false info
o Cause: lack of vitamin thiamine (alcoholics)
• Give them thiamine to prevent it in future but cannot reverse damage done.
Patient KC
• A patient who sustained damage to the cortex that renders him unable to form and retrieve new episodic memories. Was in a motorcycle accident at age 30. Can no longer retrieve any personal memory of his past, but his general knowledge remains in tact. Damage to the left frontoparietal and right parieto-occipital cerebral cortex, and severe shrinkage of the hippocampus and nearby cortex. The bilateral hippocampal damage accounts for his anterograde declarative amnesia.
Episodic memory
Memory of a particular incident or particular place and time
Semantic memory
• Generalized declarative memory, such as knowing the meaning of a word without knowing where or when you learned that word
Basal ganglia
• A group of forebrain nuclei, including the caudate nucleus, globus pallidus, and putamen, found deep within the cerebral hemispheres. They are crucial for skill learning. Sensorimotor skills, perceptual skills and cognitive skills all take place here.
priming
o Change in view of stimuli because you’ve seen it before. Like seeing ST and thinking stomp becausae you recently saw that word instead of assuming it would be start
-Evident in HM
Cerebellum
A structure located at the back of the brain, dorsal to the pons, that is involved in the central regulation of movement and in classical conditioning
place cell
at HC contains many neurons that selectively encode spatial location AKA place cell. Activated in specific location if move place cell tells HC and brain is re-mapped.
o Birds who hide food have high place cells
What is Working memory made up of?
STM + other stuff (episodic buffer; central exec)
Two neural correlates of working memory
o Neural synchrony—how well neurons an networks are simultaneously activated
o Higher in slow wave sleep and WM
Superior autobio memory
think about past and can recall most events
Reconsolidation
o When you are giving a memory back to LTM after you could have changed it or altered it
o Can create false memory by feeding someone line like saying “did you see the broken car window” instead of “is the window broken”
o Used in hyponosis
Neuroplasticity
o Memories and events that require formation of new synapses or neurons. How CNS changes in response to environment
Synaptic changes that underlie (some) memory
o More frequently used synaptic sites take over less used synapses receptors
o Increase number of NT coming through in a successful synapse
o Start up post synaptic receptors that are not being used if one is successful
Environmental enrichment/impoverishment & dendrites
o UC—housed one rat in small cage
o IC—houseed multiples rates in normal conditions
o EC—housed multiple rates in better conditions
o Found that in EC
• Higher cortex in somatosensory visual areas
• More dentric branches on neurons
• More neurons in HC
• Better recovery from brain damage.
Hebbian Synapse
pre and post synaptic connection becomes stronger because they are repeatedly activated together
Synaptic plasticity & habituation
o ST—aplysia retracts gill when squirted with water but after a while it takes longer for it to retract it because less NT will respond to it
o LT—aplysia squirted over time will respond less quickly until after days it does nothing in response
Synaptic plasticity & associative learning (Fig 13.20 generally – not names of nuclei)
o (CC) bunnies blink at tone and it is then paired with a buff of smoke. Found that HC is not needed for this but rather the cerebral circuit. US/CS converge in cerebellum
Long-term potentiation (LTP): outcome, physiologically
o NMDA usually blocked by Mg 2+ but repeated AMPA activation. Depolarization drives out Mg2+ and Ca rushes in cause an increase in LTP and increased AMDA receptors to membrane and NT increase
