Learning and Memory Flashcards
- Korsakoff syndrome
- alcohol abuse
- nystagmus and dysmetria
- gait was mildly ataxic
Oscar
‘______ ______ is absolutely dynamic’
Human memory
are not statically ‘archived’ in neocortex but are subject to constant chance by various influences
Memories
different memories have different _____ ______
time courses
- outlasts STM but not permanent
- what you ate yesterday
Intermediate-term
is the process of storing new information
Learning
ability to store information
memory (a process)
specific information stored in a brain
memory (a content)
Remembering your first day in school (about you)
Episodic
Knowing the capital of France (about something random)
Semantic
Knowing how to ride a bicycle (showing how to do it)
Skill learning
- surgery removed amygdala, hippocampus, and temporal cortex on both sides
- profound anterograde amnesia
- short term memory normal
Henry Molaison (Patient H.M.)
H.M.’s memory deficit was severe, but only on _____ _____
verbal tasks
- radar tech
- was stabbed through his right nostril, then leftward into his brain
- damage to mediodorsal thalamus, mammillary bodies
- normal short term memory but cannot form long term declarative memory
Patient N.A.
Patient N.A. had damage to the ________ _________ and _______ _________
mediodorsal thalamus, mammillary bodies
- amnesia caused by a lack of thiamine
- especially in chronic alcoholics (Oscar)
Korsakoff syndrome
- rode his motorcycle off an exit ramp
- was comatose with dilated fixed pupils
- had a bilateral hippocampal injury
Patient K.C.
Patient K.C.’s diagnosis
bilateral hippocampal injury
- can acquire new semantic memories
- ex: layout of his house
K.C.’s semantic knowledge is spared
- no personal details can be recalled
- ex: severe injury at families cottage that caused surgery and crutches for over 6 months
K.C.’s episodic memory is obliterated
- not importance of information
- helps memory
emotional arousal
- person experiences their first kiss
- body is strongly aroused
- context is obvious
Initial experience
Seperate nodes for emotions, sounds, smells, colors, tactile and other sensations
Memory is stored un network
- unwanted recall of fearful stimuli creates a fee-forward loop
- each recall causes emotional reaction that reinforces that memory
Post traumatic stress disorder (PTSD)
- increases serotonin and oxytocin
- inhibits the amygdala
- now approved for PTSD treatment
Ecstasy
words and pictures are linked in our ______
brain (in the corpus colosseum)
________ is not location of long-term memory
Hippocampus
- of memory involves hippocampus
- takes time to occur
- vulnerable
- changed upon recall/restorage
Consolidation
after learning enhances memory processing in hippocampus
sleep
sleep induces _______ _______ between hippocampus and medial prefrontal cortex (mPFC)
information transfer
This transfer _____ ______, so new memories become stable
consolidates memories
_______ is changed upon recall/restorage
Memory (eye-witness testimony)
- ‘it hit’ vs ‘it smashed’
- higher speed when ‘smashed’ vs ‘hit’
- broken glass seen when ‘smashed’
Elizabeth Loftus (car accident)
- encoding episodic memories
- retrieving episodic memories
Hippocampal memory system
- sensorimotor skills
- perceptual skills
- cognitive skills
skill learning
mirror tracing
sensorimotor skills
learning to read mirror-reversed text
perceptual skills
planning and problem solving
cognitive skills
- new declarative memories
- temporal/spatial memory
hippocampus
- memories that involve emotions
- PTSD, fear
amygdala
- source memory
- ‘memory for context in which something was learned’
- remembering how you learned something
prefrontal cortex
Older people show impaired internally generated memory, but respond well to ______ _____
external cues
_______ and _______ memories remain stable
autobiographical, semantic
- spreads through the brain
- cerebral cortex shrinks as neurons die
Alzheimer dementia (disease)
- loss of recent memory
- faulty judgment
- personality changes
mild alzheimer progression
- verbal and physical aggression
- agitation
- wandering
- sleep disturbances
- delusions
moderate alzheimer progression
- loss of all reasoning
- bedridden
- incontinence
severe alzheimer progression
extracellular accumulation of beta-A4 amyloid
plaques
intracellular accumulation of tau
neurofibrillary tangles
protein ___ stabilizes microtubules
tau
In AD, tau changes so microtubules ______
collapse
tau proteins _____ to form neurofibrillary tangles
clump
______ converts tau from a normal to a toxic state
AmyloidB
amyloid and tau _____ ___ in brains of Alzheimer patients
build up
AmyloidB is produced from amyloid precursor protein in membrane of neurons
Build up part 1
in synapses between neurons, amyloidB clumps (plaques)
Build up part 2
amyloidB clumps outside and in blood vessels active microglial cells to release inflammatory chemicals
Build up part 4
misfiled tau aggregates into neurofibrillary tangles inside neurons
Build up part 5
misfiled tau passes through synapses to other neurons, where it triggers further misfolding of tau
Build up part 6
process repeats and the disease spreads from neuron to neuron
Build up part 7
- forgetting where you left things
- having troubling remembering what you just read
- walking into a room and forgetting why you entered
- not being able to retrieve information
- blocking (calling someone by a different name)
Normal forgetfulness
mechanisms of memory stage
change in synapses
first proposed that memory is stored as an anatomical change in the strength of neural connections
Ramón y Cajal (1894)
a synapse is ______ if it can change the strength with which it affects its target
plastic
________ changes at synapses store memory
anatomical
- presynaptic, postsynaptic, or both
- increased neurotransmitter release, or effectiveness of receptors
anatomical changes at synapses store memory
inputs from other neurons _____ or _____ neurotransmitter release
increase, decrease
- if presynaptic axon & postsynaptic neuron are active at the same time-synapse is strengthened
- if presynaptic axon is active but postsynaptic neuron is inactive- synapse is weakened
Don Hebb’s hypothesis
Rats raised in enriched condition (Manhattan) had
- behavioral benefits
- cerebral changes
- promoted better learning and problem solving
- aided recovery from conditions such as malnutrition
- protected against age-related decline in memory
Behavioral benefits
What happens to neuron structure to produce a memory?
Dendritic spines changing
LTP
Long - term potentiation
Synapses in LTP are like
Hebb synapses
Tetanus drives repeated firing
Synapses in LTP #1
Postsynaptic targets fire repeatedly due to stimulation
Synapses in LTP #2
Synapses get stronger
Synapses in LTP #3
AMPA and NMDA receptors in LTP in _______
hippocampus
glutamate first activates AMPA receptors
Receptors in LTP in Hippocampus #1
NMDA receptors do not respond until enough AMPA receptors are simulated to partly depolarize neuron
Receptors in LTP in Hippocampus #2
NMDA receptors at rest have a magnesium ion block their calcium channels
Receptors in LTP in Hippocampus #3
after partial depolarization Mg++ is removed & NMDA receptors allows Ca++ to enter in response to glutamate
Receptors in LTP in Hippocampus #4
the large Ca++ influx activates protein kinases
- enzymes that phosphorylate (activate) many things
Receptors in LTP in Hippocampus #5
Now there are 2 AMPA receptors in membrane, which unblock more NMDA receptors
Receptors in LTP in Hippocampus #6
AMPA up regulation is _____-______
short-lived
CREB binds to DNA promoter regions
neurochemical cascade during induction of LTP #7
CREB changes the transcription rate of genes
neurochemical cascade during induction of LTP #8
these genes produce proteins to change ______ ______ and contribute to LTP
synapse structure
other proteins block CREB’s ability to affect gene transcription
long-term potentiation
they compete with CREB for binding sites and thereby _____ formation of long-term memories
disrupt
- increasing postsynaptic receptors
- increasing transmitter release
LTP increases effectiveness of synapses by
in normal aging, hippocampal atrophy reflects change in its volume, but not loss of _______, may be a loss of dendritic branches, decreased cell size, or loss of glial cells
neurons
loss of dendritic branches
arborization
neurons die in
Alzheimer dementia
- cause hippocampal atrophy
- to allow better response to transient stress
reduces cortisol
expression in hippocampus, which prevents hippocampal degeneration
prompts nerve growth factor
cushions loss of synapses in aging
enlarges neural networks
- reduces cortisol
- prompts nerve growth factor
- enlarges neural networks
enriched early experience
living in active environments and involvement in cognitive activities reduces cognitive decline
late enriched experience helps too