memory systems

what is the distinction between learning and memory?

if you can recite it unprompted, you have learned it

what is declarative memory?

learned facts from books/sources

what is non-declarative memory?

learned skills/cannot be learned from books

what is the process of short-term to long-term memory consolidation?

sensory info → short term memory →\[consolidated\]→long term memory

or

sensory info →\[consolidated\] →long-term memory

what is working memory?

the space in which memories are stored for a shorter period of time before being consolidated in long-term memory or being lost

what is the digit span of the short-term memory?

7-digits, Miller’s Magic number

what effects retention rates?

if numbers are written/heard

what is amnesia?

loss of memories

what is retrograde amnesia?

the loss of autobiographical memories/memories of the past

what is anterograde amnesia?

the inability to form new memories

what is transient global amnesia?

the loss of memories, both retrograde and anterograde; occurs after an accident \[common\]

\
anterograde resolves itself overtime

what causes global transient amnesia?

trauma / ischemias

what is an engram?

also called memory trace

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a physical representation of how cells interconnect and help form connections between figures/words

how are Hebb cells assembled?

Hebb cells are reciprocally connected

what is the purpose of Hebbian complexes?

are able to process visual information

\
cells that fire together wire together

where are memories based on visual discrimination stored in the brain?

IT cortex (inferotemporal cortex)

What happens if lesions are present on the IT cortex of the brain?

brain cannot distinguish things visually, uses other senses to determine what objects are (food for example)

What is Kluver-Bucy syndrome?

lesions bilaterally on IT

can perceive objects but cannot differentiate what they are

How is face recognition measured in humans?

fMRI

How is facial recognition measured in monkeys?

electrodes measure activity in the IT cortex when monkeys are presented with different faces

What research did Wilder Penfield specialize in?

epilepsy research, did lobotomies

how did Penfield perform his work?

stimulated areas of the brain during lobotomies, asked patients what they experienced

what did Penfield discover?

that all the parts of the brain are connected and important for memory storage, and memories are not all stored in one area

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removed temporal lobe for epilepsy

what happened when Penfield removed the temporal lobe?

memories were not erased

What part of H.M.’s brain was removed?

medial temporal lobe

what symptoms did H.M. have?

primarily severe anterograde amnesia, some retrograde amnesia

\
still had working memory, could learn new skills (nondeclarative)

did not have capacity for learning new facts (declarative)

how does information flow through the medial temporal lobe?

cortical association areas → parahippocampal & rhinal cortical areas → hippocampus →thalamus, hypothalamus

what is the cortical association area?

receives specific sensory info from senses that contribute to memory

what is the parahippocampal & rhinal cortical area (P&RCA)

neurons sent from CAA sent here in a circuit

what type of memory flows through the medial temporal lobe?

declarative

describe the setup for the Delayed Non-Match Sample (DNMS) test.

monkey was shown food pellet under red shape, trained to pick that up

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introduced new stimulus that now had the food under it

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now responds to new stimulus

what was being observed in the DNMS test?

tested for working memory consolidation

what occurs in the DNMS test for monkeys with brain lesions on medial temporal lobes?

decreased response rate

What memory type was still intact for monkeys with medial temporal brain lesions?

working memory

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remembered which stimulus had food immediately after, but given time did not retain

where do mammillary bodies project to?

anterior nucleus of thalamus

Where do the amygdala and IT cortex project to?

dorsomedial nucleus of thalamus

where does the dorsomedial nucleus project to?

frontal cortex

what issue did N.A. have? (what part of his brain was effected?)

lesion to dorsomedial thalamus

which 2 structures are important for declarative memory consolidation?

medial temporal lobe

dorsomedial nucleus

describe the Radial Arm Maze test

there are multiple pathways with and without food for a mouse to go down

what did rats learn to do after several tests?

rats learned to go down paths that specifically had food

what did rats with bilateral hippocampal lesions do in the radial arm maze?

learned to go down arms, did so inefficiently

\
avoided arms with no food trial to trial

((((((((((working memory impaired)))))))))))

describe the Morris Water Maze

mice are placed into a hazy water tub with a raised bench; they must swim to the raised bench

what did rats with bilateral hippocampal lesions do?

were able to make it, did so inefficiently

could not remember/form environmental cues over

((((((((working memory impaired)))))))

what cells were destroyed in the Morris Water Maze?

place cells

What do hippocampal place cells do?

help form environmental cues based on stimuli

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ex. spatial awareness for finding the door in a new room

What is the neuron’s place field?

location that evokes maximal response from a given neuron

what happens when the stimulus is blocked? partially blocked?

blocked: no response from place cell (stimulus not seen)

partially blocked: response from place cell

What happens to place cells when the box is rotated?

place cells still light up the exact same

true/false: place cells are not dynamic and cannot navigate new environments

false

what is the purpose of place cells?

help in navigation of new environments

how are place cells measured in humans?

PET scan

what two maps are made within the hippocampus?

spatial: fire emblem map

relational map: objects orders to each other

what two parts of the brain make up the striatum?

caudate + putamen

what type of memory is involved in the striatum?

procedural memory

movement, doing things (affected w AZ disease)

where does info that filters into the striatum come from?

ftronal and parietal cortex

where is the motor output sent to? what are they involved in?

thalamic nuclei and cortical areas

movement

What type of memory does the radial arm maze with lights test for?

procedural

what do the rats associate with lights?

food, go down tunnels with light first

what do rats with hippocampal lesions do?

performed fine in light maze (procedural)

performed bad in standard maze (working)

what do rats with striatal lesions do?

performed bad in light maze (procedural)

performed well in standard maze (working)

What is a test for working memory in humans?

playing a card game; asking people to sort the cards really vaguely and telling them they’re doing it wrong

can individuals with frontal lobe damage complete this task?

no

what is the prefrontal cortex involved in?

self-awareness, complex understanding and problem solving

describe the pathway of input to the frontal cortex

medial temporal lobe →dorsomedial nucleus of the thalamus → frontal cortex

what is the fornix?

connects cerebral hemispheres, aids in memory storage and recall