Memory and Learning 1

Question 0

define:memory

Answer 0

persistence of learning in a state that can be revealed at a later time

Question 1

define:learning

Answer 1

process of acquiring new info

Question 2

define:encoding

Answer 2

processing of incoming info to be stored

Question 3

define: storage

Answer 3

result of acquisition and consolidation

Question 4

define: retrieval

Answer 4

utilisation of stored info to create a conscious representation or to execute a learned behaviour

Question 5

how is memory classified ?

Answer 5

short term and long term
long term split into declarative and non declarative
declarative split into episodic and semantic
non declarative split into priming, skills and habits, non-assocative conditioning and associative conditioning

Question 6

what is sensory memory ?

Answer 6

lifetime of milliseconds to seconds- ultrashort- normally half a second
associated with a sense
unless you immediately think about it then its lost
visual, iconic, auditory or echoic memory

Question 7

what is short term memory ?

Answer 7

lifetime of seconds to hours

has a capacity limit to it - typically around 7 items

Question 8

what is long term declarative memory?

Answer 8

lifetime of days to years

recalling an event from your childhood- these are memories from your short term which have been consolidated

Question 9

what word is used to describe a memory which is rememebered in your long term memory?

Answer 9

consolidation

Question 10

describe declarative memory?

Answer 10

explicit memory 
recalled by conscious effort 
highly flexible- involves multiple sources of info 
episodic= events 
semantic=facts

Question 11

describe non-declarative memory

Answer 11

procedural memory/implicit memory
skills and associations acquired at an unconscious level
rigid memory store
commonly involved in training reflexive motor or perceptual skills

Question 12

what brain areas are involved in procedural memory ?

Answer 12

basal ganglia and cerebellum

Question 13

what brain areas are involved in declarative intermediate memory ?

Answer 13

hippocampus- particularly important in episodic memory- it is eventually transferred to long term memory in the cerebral cortex

Question 14

what brain areas are involved in long term memory?

Answer 14

cerebral cortex

specific types of memory are stored in specific cortical areas

Question 15

what is amnesia?

Answer 15

its the pathological forgetting of things

Question 16

what is retrograde amnesia?

Answer 16

difficulty in retrieving memories

Question 17

what is anterograde amnesia?

Answer 17

inability to establish new memories

Question 18

how have regions of the brain been associated with memory?

Answer 18

patients which have amnesia have helped determine the areas which are involved in memory

Question 19

what happened when patient H.M had a bilateral medial temporal lobectomy for severe epilepsy ?

Answer 19

helped to reduce the very severe seizures which he underwent
normal cognitive functioning
intact declarative memory for events preceding the surgery
severe anterograde amnesia for all declarative long term memory
intact short term memory
intact procedural memory

Question 20

what did the effects of patient H.M determine?

Answer 20

showed that regions around the temporal lobe are very important in memory

Question 21

what is the link between the hippocampus and AD?

Answer 21

hippocampus is one of the first regions affected in AD- massive cell loss linking to loss of memory

Question 22

what does the hippocampus play a key role in ?

Answer 22

declarative memory

Question 23

what brain systems are involved in the formation of declarative long term memory ?

Answer 23

hippocampus
mammillary bodies
dorsal thalamus
rhinal cortex

Question 24

what brain systems are involved in storage of declarative long term memory ?

Answer 24

neocortex | frontal cortices on dorsolateral and anterolateral aspects

Question 25

what are the subdivisions of thee hippocampus and how are they connected ?

Answer 25

``` subiculum CA1 CA3 dentate gyrus DG linked to CA3 CA3 linked to CA1 CA1 linked to subiculum subiculum and CA1 project back to entorhinal cortex ```

Question 26

what is the hippocampal circuity important for ?

Answer 26

synaptic plasticity

Question 27

what is the perferent pathway in the hippocampus circuitry?

Answer 27

starts at the entorhinal cortex into the dentate gyrus then mossy fibres from DG to CA3 then from schaffer collaterals from CA3 to CA1 CA1 to the subiculum and it also sends inputs back to the entorhinal cortex

Question 28

what are the pyramidal cells of the hippocampus innervated by ?

Answer 28

24 different inhibitory gabergic interneurons each has its own function in memory they are thought to be involved in consolidation while we sleep- neuronal firing replays to help consolidate they form gamma and theta rhythms

Question 29

what is reference memory ?

Answer 29

using learnt cues to remember rewards

Question 30

what is remote memory?

Answer 30

long term memories (months/years) that have to be recalled to solve a task

Question 31

what are the long term memory stores of spatial memory ?

Answer 31

reference and remote memory

Question 32

what is the morris maze test ?

Answer 32

used to test hippocampal function in rodents rodents are placed in a milky coloured solution containing a platform for them to find the rodents swim around randomly to find the platform and after training (10 trails) they learn where the platform is by using visual cues rodents with a hippocampal lesion cannot learn where the platform is so even after continuous trials they cannot remember where the platform is so they swim around aimlessly

Question 33

what is the radial arm maze?

Answer 33

used to test hippocampal function in rodents - test their working memory there are 8 arms each with food at the end of them so the rodent has to remember which arm it has gone down to prevent it wasting time- normal rodent only goes down each arm once by using visual cues to remember which ones it has already been down hippocampal lesion rodents cant remember which arms they have already been down so they will go down the arms more than once

Question 34

how did patients H.M have normal working memory?

Answer 34

because his prefrontal cortex was still intact

Question 35

what memory is used when the radial arms of the maze only have rewards down a subset of the arms?

Answer 35

reference memory a normal rodent will be able to remember which arms are baited whereas a hippocampal lesioned rodent wont be able to remember and learn the spatial strategy so it cant navigate it

Question 36

what happens when the AMPA receptor GluA1 subunit is knockout in the radial arm test ?

Answer 36

they can form reference memory but not working memory

Question 37

what does it show by the knockout of GluA1 only affecting working memory?

Answer 37

it shows that the underlying elements of memory formation are dissociable - not all memory formation is linear

Question 38

what are the 4 main types of neurons within the hippocampus for spatial cognition ?

Answer 38

place head direction grid boundary

Question 39

what does the neurons involved in spatial cognition do?

Answer 39

provide the "where" of episodic memories - place cells fire to tell you where you are in space

Question 40

how were firing deficits in the CA3 pyramidal neurons caused?

Answer 40

caused by knockout of NR1 | it caused behavioural deficits

Question 41

what is unusual about london taxi drivers?

Answer 41

they have a larger hippocampus compared to the average person

Question 42

what does synaptic plasticity underlie?

Answer 42

memory and learning

Question 43

what do the neuronal connection in the hippocampus allow ?

Answer 43

flow of electro-chemical transmission - it causes charges and potentials

Question 44

what do signals in the hippocampus cause?

Answer 44

depolarisations causing a change to the extracellular and intracellular current - this can be measured using electrodes

Question 45

what are extracellular recordings like?

Answer 45

the electrode is placed just next to the neuron | records the activity of 100s of neurons at one time

Question 46

what are intracellular recordings like?

Answer 46

these are specific because they break through the neuron and record activity in that cell

Question 47

define synaptic plasticity:

Answer 47

modification between the connections between neuronal pairs- changing the strength present in many brain regions but particularly in the hippocampus

Question 48

how was plasticity found?

Answer 48

by artificially stimulating the afferents in rabbits | resulting extracellular recordings were larger and lasted for weeks afterwards

Question 49

what is the difference between long term potentiation and long term depression ?

Answer 49

LTP- connections are strengthened | LTD- connections are weakened