Memory Flashcards
What is needed for long term memory?
Proteins
Involved in perceptual priming
Sensory systems
Protein kinases (PKM) prevents the removal or AMPA receptors. Lasts indefinitely
Maintenance (stage 4 of synaptic strengthening)
BDNF produces sustained calcium release. Protein synthesis contributes to stability. Lasts about 2-4 hours
Consolidation required (stage3 of synaptic strengthening)
What is the most beneficial way to prevent cognitive decline?
Social interaction and physical exercise as opposed to video games or isolated/stationary tasks
High amounts of this cause impairments in consolidation and retrieval
ACh
What happens in storage/consolidation?
Neural trace formed via synaptic plasticity across neurons and brain regions to form a physical representation of a memory
Learning new info
Encoding
What does increased activation of the hippocampus and parahippocampal gyrus predict?
Improved later remembering
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Process of accessing stored memories (remembering)
Retrieval
Essential to memory functions and has differential effects in different stages of memory
Acetylcholine (ACh)
Parts of non declarative (implicit) memory
Procedural memory (how to), associative learning (conditioning), and non associative learning (habituation and sensitization)
Involved in conditioned responses between two stimuli
Cerebellum
What is less likely to be modified due to reconsolidation?
Strong, older memories
Patient HM cause of surgery
Severe temporal lobe epilepsy
Involved in habituation and sensitization
Reflex pathways
Has unlimited capacity and lasts indefinitely
Long term memory
Presynaptic differences in long term potentiation
More vesicles
Part of the brain involved with naming animals but not tools
Brocas area and left medial occipital lobe
Long term potentiation as a memory mechanism
Strongest link we have to memory formation. Associativity, cooperativity, and persistence
Parts of declarative (explicit) memory
Semantic (facts) and episodic (what happened)
What is contained in working memory?
A central executive, phonological loops, episodic buffers, and visuospatial sketchpads
What happens to most info that hits sensory memory?
It is forgotten
What two parts of the brain support the central executive in working memory?
Dorsolateral prefrontal cortex and anterior cingulate cortex
What are long lasting memories?
Stories we all have and like to tell that strengthen over time but aren’t as accurate. Strongest memories as time goes on
What do a little and a lot of stress cause?
Little = boosted performance Lot = reduced performance
What are the possible underlying changes that cause healthy aging of memory?
White matter deterioration, poor sleep quality, and difficulty clearing adenosine
What does memory retrieval stimulate?
Same consolidation processes responsible for original learning
Patient HM retrograde effect
Gradual episodic amnesia to about 10 years. More impaired closer to surgery
Production of proteins by RNA
Translation
Extraordinary episodic recall associated with larger amygdala volume and greater amygdala to hippocampus connectivity
Hyperthymesia
Levels or cortisol and helpfulness/harmfulness
A little is helpful and a lot negatively impacts cognitive function
Involved in encoding and consolidation of memories and long term potentiation
Glutamate
What leads to hypersensitivity to stressors?
Dendritic changes in the amygdala
How can info stay in short term memory longer?
Rehearsal
What is the contemporary (new/improved) thinking of models of memory?
Formation of memory trace involves hippocampus and cerebral cortex simultaneously and ability to recall memory shifts from hippocampus to cortex
Patient HM anterograde effect
Complete amnesia for episodic memories
What are the two important areas often studied in the hippocampus?
Area CA and area CA3
What do amnesia patients show compared to normal adults on items on list recall
Less primacy effect and less overall. Similar in recency effect
What is a phonological loop?
Remembering words. Working memory
Electrical activity differences in long term potentiation
Higher electrical activity
Patient HM implicit memory effect
No impairment, procedural in tact and could learn new skills
What may fail as dementia develops?
Compensation
What is the hippocampus important in for memory and not as important in for memory?
More important for short term memory and less critical for later recall
Anterior cingulate cortex and working memory capacity
Small activation accompanies maintenance rehearsal and large activation accompanies semantic (elaborate) rehearsal
Inability to encode new memories from our experiences
Anterograde
Involved in specific personal experiences from a particular time and place
Hippocampus
What is a visuospatial sketchpad?
Remembering an image. Working memory
What does stress effecting the medial prefrontal cortex cause?
Reversible atrophy of dendrites and less responsiveness under stressful conditions
What parts of memory are separable in memory with stress?
Episodic and emotional components
What happens when the thalamus or mammillary bodies are lesioned?
Patients show amnesia
Calcium levels continue to increase. The spine is enlarged. Lasts about 15-20 minutes
Stabilization required (stage 2 or synaptic strengthening)
What is true of memories we have the most confidence in?
They aren’t always the most accurate
Copying of DNA to RNA
Transcription
What do AMPA receptors cause?
Mg2+ to leave NMDA receptors
What happens to info unrelated to the stressful situation?
It is suppressed. Stressful times get the focus
Loss of memories from our past
Retrograde
What does stress trigger the release of?
Epinephrine from the adrenal glands into the circulation
Atkinson-Shiffrin model of memory parts
Sensory memory, short term memory, and long term memory
What healthy changes occur in healthy aging of memory?
Slower eyeblink conditioning, slower rxn time, working memory decline, and formation of new episodic memories declines
Steps of long term potentiation
- ) Apply weak stimulus
- ) Apply strong stimulus
- ) Apply rapid shocks
- ) Apply weak stimulus again
Operates over a few seconds, temporary storage, manipulates info, and focuses attention
Working memory
Short term memory capacity
7+ or - 2 (5-9)
How is the striatum involved in procedural memories?
Match procedures to context and likelihood of reward. Thinking about what fingers do when playing a song.
What is the Hebb rule?
Neurons that fire together wire together
What happens to synapses when info is retrieved
They are weakened
What provides a basis for learning and memory through the application of a rapid series of electrical shocks to input pathways increasing the postsynaptic potentials in their target neurons?
Long term potentiation
What does repeated exposure to similar events cause in semantic and episodic memory?
Strengthens semantic memory and weakens episodic memory
Why is a hippocampal slice beneficial in looking at long term potentiation?
You can look at some circuits and not all of them together
What is the gateway to the hippocampus that allows the whole brain to access the hippocampus through?
Entorhinal cortex
4 steps of stress effecting memory
- ) Epinephrine binds to vagus nerve which reports to the locus coeruleus via the nucleus of the solitary tract
- ) The locus coeruleus released norepinephrine
- ) Norepinephrine in the amygdala and hippocampus enhances memory formation
- ) Epinephrine produces glucose release from liver, supporting signal cascades required for memory formation
Process of forming a physical representation of a memory
Storage/consolidation
What can excessive amounts of glutamate cause?
Neuronal damage
Do NE or glucocorticoids levels return to normal first?
NE
What do 2 synapses instead of one increase?
The likelihood of activation
What is working memory? Where is it?
Manipulating info in some sort of way. In short term memory
This enhances hippocampal activity in emotional memories
Amygdala
Involved in world knowledge, object knowledge, language knowledge, and conceptual priming
Cortex
Patient HM long term memory effect
No episodic impairment for childhood
What do NE levels returning to normal initiate?
Shift to a memory storage state
Effects of stress on memory
Reduced hippocampal volume and medial prefrontal cortex
What does reconsolidation do?
Updates memory to include ongoing info at time of retrieval
Impacted parts of patient HM brain
Bilateral medial temporal lobe, hippocampus, and amygdala
What is the hippocampal formation made up of?
Hippocampus, dentate gyrus, subiculum, parahippocampal gyrus, and entorhinal cortex
What are the dorsolateral prefrontal cortex and anterior cingulate cortex important in?
Object permanence
Involved in motor and cognitive skills
Basal ganglia
What do the stress induced actions of NE and glucocorticoids in the amygdala initiate?
A memory formation state in the prefrontal cortex, the hippocampus, and the caudate nucleus
When is linked to alcoholism and amnestic confabulatory (Korsakoffs) neurocognitive disorder?
Thalamus and mammillary bodies
Interferes with both long term potentiation and spatial memory acquisition
NMDA antagonist (APV)
What happens when glutamate is blocked?
Memory receptors are blocked
Hippocampus inputs and outputs
Hippocampus to entorhinal cortex to perihinal cortex and parahippocampal cortex to frontal, parietal, temporal, occipital, and cingulate cortices. Works bi-directionally, feedback to cortex
What remains the same in aging?
Cognitive measures (intelligence)
What happens with electrical activity in delay cells?
Increased electrical activity in delay cells and it goes away with a response
What is the traditional (old/outdated) thinking of models of memory?
Short term memories held in hippocampus, memories transferred to cortex and memories erased from hippocampus
Areas of the brain involved with naming tools but not animals
Left premotor area and left middle temporal gyrus
What is an episodic buffer?
Relating info to life that nobody else can do. Working memory
This occurs in waves over time
Consolidation
What does retrieving a memory do?
Makes it vulnerable
What are Loftus and reconstructive memories involved in?
Reconsolidation
High amounts of this are helpful in encoding
ACh
What do at risk adults for AD show?
Increased hippocampal activity during encoding. Having to work harder for same amount of result
Postsynaptic differences in long term potentiation
More Ca2+. More receptors
What is a similar phenomenon to long term potentiation that produces reduced responses
Long term depression
What do glucocorticoids initiate?
Changes in gene expression
How does info get from sensory memory to short term memory?
Attention
This is activated during effortful attempts at retrieval
Prefrontal cortex
What does reduced hippocampal volume cause?
Reversible atrophy of dendrites and reduced neurogenesis
What is role of transcription factors in memory consolidation?
Importance of CREB (cAMP response element binding protein)
What is anisomycin?
Protein synthesis inhibitor
How does memory get from short term memory to long term memory?
Encoding
What makes up the striatum (basal ganglia)?
Caudate nucleus, putamen, and nucleus accumbens
What type of info is more likely to be remembered over?
Highly arousing, negative info is more likely to be remembered than non-arousing, positive info
4 stages of synaptic strengthening
Generation, stabilization required, consolidation required, and maintenance
Calcium enters the postsynaptic area. Additional AMPA receptors are inserted. Lasts about 1 minute
Generation (stage 1 of synaptic strengthening)
