memory Flashcards
what is memory
ability to store information from past experience and retrieve it
what does having memories cause (2)
- consciously recollect things
- changes in behavior
what is learning
processes through which new information is acquired by cns
what is equivalent of learning in brain
plasticity
habituation vs sensitization
habituation -> learning to ignore novel stimulus (lose reflex)
sensitization -> heightened response when paired with harmful stimulus (reflex becomes better)
cellular and molecular mechanisms of learning (2)
- long term sensitization
- long term habituation
molecular changes of learning (2)
- structure in presynaptic terminals changes
- functional effectiveness of preexisting synapse changes
what is declarative/explicit memory
memory of semantics (facts/concepts) and episodic memory (events)
what is nondeclarative/implicit memory (4)
- priming
- associative learning (conditioning)
- procedural memory (motor learning like riding a bike)
- nonassociative learning: habituation and sensitization
qualitative categories of memory classification (2)
- declarative/explicit memory
- nondeclarative/implicit memory
temporal categories of memory classification (3)
- immediate (sensory memory) -> ~ 1s
- stm (working memory) -> s to min
- ltm -> days to years
what helps consolidate stm to ltm
sleep
what information is found in working memory
information relevant to achieve a goal
limitations of working memory (2)
- duration
- capacity
what is working memory pertinent for (2)
- language reasoning
- problem solving
brain circuits involved in working memory (3)
- phonological loop -> broca and wernicke’s area to pfc
- visuo-spatial sketch pad -> occipital lobe to pfc
- episodic buffer (perceptual processing) -> parietal lobe to pfc (and vice versa)
what is consolidation
progressive stabilization of memories that follows initial encoding of memory ‘traces’ through conscious or unconscious rehearsal or practice
what is an engram
physical embodiment of any memory in neural machinery: changes in efficacy of synaptic connections, growth or reording of connections
where is the engram
cortex
where are memory traces
hippocampus
what leads to persistence of memories at the cellular level
changes in protein synthesis and other mechanisms of synaptic plasticity
where do memories go to be consolidated
from hippocampus to cortex
what does priming do
changes processing of 2nd stimulus due to previous encounter with the same or related stimulus
what does priming show us
importance of association
priming in schizophrenic patients
associations not as strong so priming doesn’t really work
things that enhance memory span (3)
- associating
- giving meaningful context to meaningless items
- motivation
classical conditioning vs operant conditioning
classical -> pair normal trigger with unrelated stimulus (repeated association), eventually unrelated stimulus elicits response
operant -> increasing behavioral response by associating response with reward
which type of conditioning is (a) passive, (b) active
(a) classical
(b) operant
what do we forget (2)
- things with no particular importance
- unused or unrehearsed memories over time
pathological process of forgetting
amnesia
types of amnesia
retrograde -> can’t remember things that happened before
anterograde -> can’t form new memories (like blackout from alcohol)
brain structures that have role in establishing new declarative memories (2)
diencephalic and medial temporal lobe structures
brain systems/structures underlying memories (3)
- diencephalic and medial temporal lobe structures
- hippocampus and amygdala
- limbic system
part of the limbic system in hippocampus (3)
- parahippocampal gyrus
- entorhinal cortex
- perirhinal cortex
subcortical connections to thalamus and mamillary bodies
hippocampus and amygdala
patient hm (3)
- had epilepsy
- removal of temporal lobe bilaterally
- epilepsy cured, but anterograde amnesia
what did patient hm lose (3) and what was preserved (2) (in terms of memory)
- recollection of early memories preserved (because already in cortex, not in hippocampus anymore)
- recollection of having met dr. milner lost
- capacity to encode new events and facts lost
- procedural memory preserved
- recollection of having learned motor skill (not acquired before lesion) lost
conclusion from patient hm’s memory performances
different brain systems underlie different aspects of memory
medial temporal structures involved in … of … memories
encoding and consolidating declarative memories
role of medial temporal structures in procedural and ltm memories
procedural and ltm independent from medial temporal structures
what does activation of hippocampus and adjacent cortex predict
memory performance
what does the quality of encoding depend on
structural and functional changes of neural connections as a result of experience
what brain area is relevant for remembering
posterior hippocampus
what cells make up the brain’s gps
place cells and grid cells
location of place cells and grid cells
place cells -> hippocampus
grid cells -> entorhinal cortex
what are place cells and grid cells
place cells -> neurons that fire when animals traverse specific locations
grid cells -> neurons that fire when rat was in different parts of the arena that formed a hexagon (fires for 6 different places)
how can brain navigate
combination of place and grid cells maps location in relation to other things
what system does procedural learning depend on
motor system
procedural learning is affected in (2)
- parkinson’s
- huntington’s
where is ltm stored
cerebral cortex
which areas of cortex is semantic memory stored in (not hippocampus)
areas in cortex that were activated when encoding object (when saw the thing)
forms of ltm (2)
- implicit (nondeclarative)
- explicit (declarative)
brain region involved in (a) priming, (b) procedural learning (not motor system), (c) emotional response of conditioning, (d) skeletal musculature response of conditioning, (e) habituation & sensitization
(a) neocortex
(b) striatum
(c) amygdala
(d) cerebellum
(e) reflex pathways
