Learning and Memory Flashcards
(41 cards)
what are some things that help you remember?
retrieval cues
context
why might we forget things?
long time ago
other memories have formed
how is the limbic system involved with memory?
has the Thalamus, Hippocampus, Mammillary bodies of hippocampus, Amygdala, Hypothalamus, and Olfactory bulb
what is memory?
the capacity to encode, store, and retrieve information
what are the three memory systems?
sensory memory –> short term memory –> long term memory
taxonomy of memory (different flavors of memory)?
short term
long term
- declarative (explicit)
- semantic (facts)
- episodic (events)
- non-declarative (implicit)
- procedural (motor skills and habits)
- priming
- classical conditioning (two stimulus = elicited response)
- reflexes
sensory memory
Information in through senses (visual, auditory, etc.) translates stimulus into things the brain can understand
Occipital lobe (visual, auditory, etc. cortex)
Unattended information is lost.
short term memory
unrehearsed information is lost
Holds the information in the mind
Maintenance rehearsal
long term memory
Some information may be lost over time
what kinds of memories does non-declarative memory (long-term) include
reflexive and motor memory
Reflexes
Procedural (skill learning and motor movement)
Stimulus-response learning
classical conditioning
Priming
associated with cortical learning, cerebellum, basal ganglia
declarative memory (long-term)
semantic memory - facts
Episodic memory - events
what is semantic memory and what part of the brain is it associated with
Factual: “I know”
Not necessarily tagged with a context
associated with lateral temporal lobe, anterior cortical area
- semantic dementia
what does episodic memory include? what parts of the brain is it associated with?
Events
Tagged with spatial and temporal context; Specific in time and place
Autobiographical: “I remember”
associated with hippocampus and medial temporal lobe circuit
- amnesia
- Alzheimer’s disease
Particularly vulnerable to age (and other hippocampal diseases); first to go
Ex: HM hippocampi were removed resulting in severe memory loss (amnesia)
Medial temporal lobe amnesia
what would an amnesic brain look like
medial temporal lobe (middle part of hippocampus) is black in the brain scan so it means there is cortical thinning (less tissue) - degenerating or missing)
what would a semantic dementia brain look like
tiny TEMPORAL LOBE, cortical thinning
not specific to medial temporal lobe (hippocampus is usually intact)
semantic dementia (picture naming, immediate/delayed drawing)
Progressive neurodegenerative disorder (gets worse over time)
Loss of semantic memory
very difficult for patients to name specific items
- Can talk but cant get to the right word ( that… thingy)
Video example: she could name most of the things on the table but switched around names of scissors and pen. Procedural, motor memory was still there
picture naming: Can name the overarching category like “animal” and can name things that are more solidified in the memory bc of more repetition (ex: dog), but cant get other less common things like bear as “animal” or frog as “little thing”
- Stronger representations of a higher level category but less so in lower level categories
immediate and delayed drawing: shown a drawing of an animal then have to draw from memory. will generalize what it looks like (ex: animals have 4 legs, so they draw a duck with 4 legs as well) and less likely to remember more unique features (ex: a camel’s hump or a rhino’s horn)
Representation of knowledge in semantic memory
- Association network hub
- Semantic information widely distributed in neocortical association networks
- Connected to semantic “hub” in anterior temporal cortex (represents concepts)
- Not linked to a specific time and place
- Gradually acquired and updated
- If you activate one node, it could activate other things and features
Medial temporal lobe amnesia (anterograde vs graded retrograde)
Anterograde amnesia (in the future):
Inability to form memories after brain damage
Have difficulty remembering what happened right before the trauma
Anterograde cant encode memories after trauma
Graded retrograde amnesia:
Loss of memories formed before brain damage
Retrograde dip could be because the recent memories were not rehearsed
Neurocircuitry of episodic memory
Neocortical association areas send projections to medial temporal lobe
Widespread cortical projections and are funneled down into medial temporal lobe then to parahippocampal region then to hippocampus (talks to different areas in the brain). Great for episodic memory bc you have to link aspects together (ex: name and location)
how does the hippocampus help with memory
Hippocampus is the apex of processing hierarchy
- forms associations between pieces of information stored in neocortex where it is sent to perirhinal cortex to get to ventral cortex
Partial cue will trigger hippocampus (serves as an indexing function of things that are associated with each other)
dorsal stream helps determine “where”
ventral helps determine “what”
dorsal stream vs ventral streams do what
dorsal - where
sent to parahippocampal cortex in medial temporal lobe. enters rhinal cortex then hippocampus
ventral “what”
- item information from temporal cortex visual stream
Perihinal cortex gets info from entorhinal
Gets input from ventral visual stream (the ‘what’)
Represent individual perceptual stimuli
Neurons do not show strong spatial coding bc it doesnt care where
Cells respond to specific stimuli when re-appearing in recognition test
Delayed-Match-to-Sample Task (when it comes to ventral stream in episodic memory)
- Increased neural activity during retention interval for faces later correctly remembered
- Hold object information in mind over 30s delay
- Even when object not visually present in the environment
What is perirhinal and what happens if it is lesioned
perirhinal helps differentiate things
uses ventral (the what) visual stream
when lesioned = can’t recognize complex objects/faces
Visual perception discrimination is impaired
Damage to perirhinal cortex results in object recognition memory deficits
* Lesions in primate perirhinal cortex impairs DMS performance (Gaffan & Murray, 1992)
* Impaired visual discrimination of complex objects and faces (Barense et al., 2007)
parahippocampal cortex
uses dorsal stream to determine the where
helps with orientation and deciding environmental context
Process spatial context
responds to “scenes” or “3D spatial layouts”
Orientation / Reorientation in space (changes depending on orientation within a room for example)
If lesioned
Impair learning spatial configuration of objects
Identity of memory for objects is not impaired
Preferentially respond to scenes rather than objects
Parahippocampal “place” area (PPA)
* Lesions to postrhinal cortex (PPA homologue) result in context recognition impairments
* No preference for exploring incongruent contexts (can’t discriminate between congruent & incongruent contexts)
