Memory Flashcards
Memory requires ___ and a meaningful utilization of information
Attention
What predicts strength of memory?
Retrieval
Neuroplasticity
Brain’s ability to use other parts of the brain to compensate for when an area is impaired
Capacity of nervous system to modify its organization
Changes in structure and function as a result of experience
Neuroplasticity requires changes within ___
Synapses
What is the dominant theory of memory currently?
Long-term potentionation
Long-term potentiation
Persistent increase in synaptic strength following high-frequency stimulation
Neurogenesis
New evidence that new neurons are formed in some regions of the brain
Changes in neuronal excitability lead to
Changes in the firing threshold
Limbic system’s association with memory
Controls emotions and instinctive behavior (includes hippocampus and parts of the cortex)
Emotional, memory, and motivational processes
Central role in long-term memory
Thalamus’s association with memory
Receives sensory and limbic information and sends it to the cerebral cortex
Maintains states of wakefulness and alertness
Hypothalamus’s association with memory
Monitors certain activities, maintains homeostasis, and controls body’s internal clock
Hippocampus’s association with memory
Where short-term memories are converted to long-term memories
Regulates learning, memory consolidation, and spatial navigation
NOT associated with the retrieval of remote memory
New episodic memory and memory consolidation
Perceptual aspects of memories, novel events, places, and stimuli
Parts of the limbic system
Cingulate gyrus, thalamus, hippocampus, hypothalamus, and amygdala
What role do motivation processes have to do with memory?
Choose what to pay attention
Areas of the thalamus whose damage leads to amnesia
Anterior nucleus
Dorsal medial nucleus
Midline
Anterior structures
Intralaminar structures
Which parts of the thalamus are associated with declarative memory?
Anterior and medial division
Which parts of the thalamus are associated with long-term memory?
Anterior and medial dorsal thalamic
Part of brain activated during novel object encounters
Hypothalamic melanin-concentrating hormone neurons
Neurotransmitters unique to the hypothalamus modify _____ in in-vitro preparations, suggesting that the hypothalamus can control memory without changing _____.
Synaptic strength, attention/motivation
Anterograde amnesia is associated with damage to
The hippocampus
Ways the hippocampus can be damages
head trauma, ischemia (inadequate blood supply), hemorrhagic stroke, acute seizures, status epilepticus (seizure longer than 5 minutes), encephalitis, tumors, drug withdrawal, exposure to chronic unpredictable stress, Alzheimer’s disease, and anoxic (loss of oxygen) brain injury
Remote memory
Memories of the distant pass
Memory consolidation
The process by which a temporary, labile memory is transformed into a more stable, long-lasting form, stores memories in like-categories
Part of the brain important for declarative memory
Hippocampus, medial temporal lobe
Recollection vs knowing
Recollection = free recall
Knowing = familiarity
Hippocampus is selectively involved in ___, not with ___.
Recollection, knowing
Process dissociation procedure revealed
Hippocampus involvement with recollection but not with knowing
Cognitive Rehabilitation Therapy (CRT) can help patients with ___ reduce hippocampal activation in the short-term
Mild cognitive impairment
Memory consolidation
Interactions among neural systems as well as cellular changes within specific systems
The amygdala is critical for modulating consolidation in other brain regions
Networks involved in recalling pictures
Right prefrontal cortex and para-hippocampal cortex
Networks involved in recalling words
Left prefrontal cortex and left para-hippocampal cortex
LTM storage occurs
In the cortex, near where the memory was first processed and held in short-term memory
Transience
Decreasing ability to reach memory over time
Hippocampus and nearby structures
Absent-mindedness
Lapses of attention causing forgetfulness
Frontal lobe
Misattribution
Remembering the information but not where it came from
Frontal lobe
Suggestibility
Filling in gaps in memory with information from others
Frontal lobe
Blocking
When trying to retrieve/encode information, but another memory interferes with the retrieval/encoding
Front of temporal lobe
Persistence
Unwanted recollections unable to be forgotten
Amygdala
Long-term memory
Consists of encoding, storage, and retrieval
Explicit memory
Recognition through verbal/nonverbal means, conscious awareness is implied as is intention to remember
Implicit memory
Conscious awareness is not always necessary, priming, skill learning, and conditioning
Declarative memory
Explicit and accessible in conscious awareness
Processing information to tag memory and consolidate for storage
Non-declarative memory
Implicit and demonstrated via performance (procedural)
Papez circuit is
The major declarative memory system
Declarative Consolidation brain structures
Medial temporal lobe, diencephalon, basal forebrain (think HM)
Hemispheric-Encoding-Retrieval-Asymmetry (HERA)
Prefrontal (dorsolateral) region of the left hemisphere linked to episodic encoding, prefrontal area of the right hemisphere linked to episodic retrieval
Non-declarative memory
memory operating outside the limbic circuitry of explicit/declarative memory
Implicit priming
occurs when a person is exposed to one stimulus, then later reacts to a similar stimulus without consciously recalling why (e.g., priming with three letter word stem from a prior list relies on visual features)
Problems with implicit priming is a common deficit of
Korsakoff’s amnesia
Artificial grammar
Grammar rules with a corresponding task, testing subjects’ ability to learn a made-up grammar in a laboratory setting
Posterior neocortex
Difficulty with artificial grammar tasks is indicative of
Basal ganglia disease/Parkinson’s
Classic/Associative learning
learned associations (e.g., pull hand away from hot surface)
Short-term memory
Limited capacity and short time frame, can only accommodate more than a few thoughts, ideas, or pieces of info
As new info arrives, kicks out old info (like a small island with only a small area of habitation)
Type of coding used by short term memory
phonological coding (e.g., things you hear, don’t tie to meaning)
Type of coding used by LTM
Semantic (meaning) coding
Connect to limbic system
STM deficits
Super rare
Damage to left posterior temporal region
Working memory (def and brain regions)
Distinct system encompassing some of the capacity limitations of STM, dynamic, influencing aspects of attention and executive fx
Retention of a small amount of information in a readily accessible form
Prefrontal, cingulate, and parietal cortices
Four components of working memory
Central Executive
Articulatory Phonological Loop
Visuospatial sketchpad
Episodic buffer
Central executive
Attention control system, coordinates subservient system (which is a proposed deficit in AD)
Focus, shifting, and dividing attention with interactions to LTM
Articulatory Phonological Loop
Stores speech-based information, important for acquisition of vocabulary
Visuospatial sketchpad
Manipulates visual and spatial images
Episodic buffer
Temporary and limited capacity storage system, hold and integrate information of different modalities (visual and auditory)
Semantic memory (definition and brain regions)
General world knowledge
Confluence of visual, spatial somatosensory, and auditory processing systems
Inferior parietal cortex
Procedural memory (def and brain regions)
Retrieving information to perform learned skills (e.g., riding a bike)
Basal ganglia, cerebellum, motor cortex
Explicit Memory (def and brain regions)
Long-term memory related to the recollection of factual info (e.g., phone numbers)
Hippocampus, neocortex, and amygdala
Implicit memory (def and brain regions)
Information not stored purposely and unintentionally memorized (e.g., a familiar song)
Basal ganglia, cerebellum
Iconic Memory (def and brain regions)
Visual sensory memories when something is seen very briefly, fast decaying store of visual information
Visual short-term memory networks and temporal lobe
Echoic memory (def and brain regions)
Auditory sensory memories (spoken language)
Primary auditory cortex, both hemispheres
Episodic Memory (def and brain regions)
Memory of everyday events, experiences occurring at a particular time and place (e.g., where a person’s car is parked)
Hippocampus, temporal lobes
Spatial Memory (def and brain regions)
Recovery and recording of locations and spatial relationships between objects, needed for planning (e.g., where you left your keys)
Hippocampus, medial entorhinal cortex
Eidetic Memory (def and brain regions)
“photographic” memory, recall an image with precision after seeing it once (e.g., recall specific details of a painting)
Posterior parietal cortex
Autobiographical Memory (def and brain regions)
Episodes recollected from an individual’s life, combination of episodic and semantic memory (childhood memories)
Frontal, temporal, occipital lobes
Memory recognition
The ability to identify information previously encountered
2 components of memory recognitions *
Recollection and familiarity
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4251874/
Recollection (def and brain region)
Retrieval of qualitative information about a specific study episode, such as when or where an event took place
Hippocampal dependent
Familiarity (def and brain regions)
Reflects a more global measure of memory strength or stimulus recency (e.g., have you seen this before?)
Adjacent perirhinal cortex
Why has testing moved towards familiarity measures over recognition measures?
To reduce the risk of yes/no bias and address possible malingering - use arbitrary scales of recognition to determine strength of confidence instead
Amnesia
Loss of memory ability, usually as a result of a lesion or surgical removal of various parts of the brain
Marked by relatively spared performance in other parts of the brain
Pure, isolated amnesia is rare
3 classifications of amnesia
- Source of the disease (illness/injury)
- Location of the area of damage
- Functional deficit (what type of memory is impaired)
4 Theoretical implications of amnesia
- STM and LTM are separate processes
- Implicit memory and explicit memory are different systems
- Semantic and episodic memory can be split apart
- Provide insight into the nature of consciousness
Amnesia causes
- Korsakoff’s
- TBI
- Alzheimer’s
- Specific brain lesions (surgical)
- Psychological (dissociative/fugue states)
- Migraines
- Hypoglycemia
- Epilepsy
- ECT
- Drugs
- Infections
- Nutritional deficiency
Transient Global Amnesia (definition, causes)
Sudden temporary interruption of short-term memory, leads to inability to make new memories
Person would likely be oriented and able to provide personal information (preserved episodic)
Mostly tied to working memory deficits
Caused by strenuous activity, high stress, coitus
More common in middle-age to older adults
Retrograde amnesia
Marked by difficulty recalling events prior to the onset of amnesia/injury
Duration varies, can be several years
Rare, short-lived, typically due to brain trauma (connect to TBI severity)
Retroactive interference
Marked by difficulty recalling previously learned information because new information is interfering
Retrograde amnesia prognosis
Indicative of being more harmful and a more significant impairment following injury than anterograde
Duration of amnesia typically reduces as time passes (e.g., week 1: pt lost 11 years, week 2: 2 years, week 3: last two years gradually returned)
Retrograde amnesia is a problem of
Retrieval (evidence from extent of memory loss shrinking over time)
Ribot’s Law
Think retrograde amnesia pattern of gradually returning memory
Recent memories are more likely to be lost than the more remote memories (first in, last out)
might reflect a failure of consolidation
Anterograde amnesia (aka post traumatic amnesia)
Marked by difficulty recalling previously learned information
Refers to period of time (typically following TBI) in which new memories cannot be consistently formed
Causes of anterograde amnesia
Lesions
Twisting and tearing of microstructure of the brain
Symptomology of anterograde amnesia
Typically lose consciousness after a TBI
After regaining consciousness, often a gradual recovery during which patients have difficulty keeping track of and remembering ongoing events
May be moments of lucidity and memory
Memory systems impacted by anterograde amnesia
- Problems of learning new facts
- Specific to episodic memory
- Procedural memories are intact
- Implicit memory performance is normal
Case of HM
Case of HM (bilateral mesial temporal lobe resection extending 8 cm back from temporal tips, destroying anterior two-thirds of hippocampus and hippocampal gyrus
Attributable to hippocampal damage, amygdala, and the adjacent parahippocampal gyrus
Anatomy of anterograde amnesia
Damage to hippocampus or to regions that supply its inputs and receive its outputs
Damage to limbic cortex of the medial temporal lobe (impacts semantic memories)
Fornix and mammillary bodies (esp. Korsakoff’s syndrome)
Neural circuit includes hippocampus, fornix, mammillary bodies, and anterior thalamus
How does the hippocampus form new declarative memories?
- Receives info from sensory/motor association cortices and subcortical regions
- Processes info and modifies the memories being consolidated through connections back to these regions
Hippocampal formation enables use to learn the relationship between stimuli that were present at the time of an event (context) and the event itself
Destruction of the hippocampus alone disrupts __, while destruction of the limbic cortex of the medial temporal lobe will also impair ___.
Episodic memory
Semantic memory (memory of facts and general info), and thus all declarative memory
Korsakoff’s Amnesia
Results from chronic alcoholism and consequent thiamine deficiency
Most associated with memory dysfunction specific to initial encoding of new info (no learning or encoding = cannot consolidate = thalamus and hippocampus)
Generally preserved IQ, including normal digit span
Personality changes (apathy, passivity, indifference), inability to formulate and follow through on plans
Lack insight into condition
What brain regions are impacted in Korsakoff’s?
Lesions to the medial thalamus
1. Dorsomedial nucleus of thalamus
2. Mammillary bodies of hypothalamus
Types of amnesia/memory impacts of Korakoff’s
Retrograde/anterograde amnesia with temporal gradient
Confabulation (rare after 5 years)
Worst impairments are on episodic memory tasks (e.g., word lists, figures, faces)
Intact memory systems with Korsakoff’s
Relatively preserved semantic memory, including normal verbal fluency, vocab, syntax, and basic arithmetic
Intact sensorimotor memory (mirror tracing, mirror reading, pursuit rotor)
Intact performance on perceptual tasks (perceptual identification, generating category examples)
Confabulation
Tendency to “fill in gaps” of one’s memories with plausible made-up stories
Psychogenic Amnesia
Marked by a gap in memory, typically tied to a traumatic event while memory for recent events remains intact
Triggered by emotional or physical stress
Retrograde loss of autobiographical memory resulting in impairment of personal identity and may be accompanied by a period of wandering
Diencephalic amnesia (def and brain regions)
Marked by temporal ordering impairment
Damage to the medial thalamus and mammillary nuclei
Associated with Korsakoff’s psychosis
Bilateral temporal lobe amnesia
Opposite of HM
significant but more subtle “semantic” memory loss rather than total amnesia
Marked by bilateral damage to the medial temporal lobe (auditory!)
May be accompanied by personality changes, irritability, depression, dementia, seizures, short-term memory loss (bilateral lobe atrophy)
3 types of memory assessments
Immediate vs delayed
Verbal vs visual
Structured vs unstructured
Correlations between subjective memory complaints and objective memory performance are generally ___ and mediated by ___
low; mood/anxiety symptoms
Verbal memory
ability to remember words, phrases, or verbally presented info
Isolated verbal memory best measured with words presented audibly and recalled verbally
Visual memory
Ability to remember objects or symbols presented visually
Typically assess ability to recall short term and long term
Isolated visual memory best measured with visual stimuli presented visually and reproduced mechanically
Learning is optimal when
Both verbal and visual attention is being utilized to store info
Immediate memory
Where we put information briefly until we make a decision about whether to dispose of it
Operates subconsciously or consciously, data held for up to 30 seconds
Delayed memory
Ability to recall specific info after a period of rest or distraction from the info
Structured Memory
Info presented in a manner that allows for use of schema, memory experience, or learned info to positively influence ability to retrieve stored stimuli
WRAML story scene, WMS logical memory
Unstructured memory
Info presented as ambiguous and novel with a direct intent to minimize the impact of prior learning of experience on the ability to store and retrieve stimuli
REY, verbal word lists
