Learning and Memory 1

Question 1

What is memory ?

Answer 1

is the process by which information is acquired,

encoded, stored and retrieved.

Question 2

what can memory be defined as ?

Answer 2

an be defined as a lasting representation that is

reflected in thought, experience, or behaviour.

Question 3

What is learning ?

Answer 3

is the acquisition of such representations - involving

a wide range of brain areas and activities.

Question 4

what did Ebbinghaus (1880’s) say about memory ?

Answer 4

memories have life-spans - repetition makes memories last longer

Question 5

What did James 1890 say about memory ?

Answer 5

distinguished habit from memory

primary vs secondary memory

Question 6

what did Korsakoff 1890 describe ?

Answer 6

amnesia

Question 7

describe the behaviourist , cognitive and biological revolutions

Answer 7

Behaviourist revolution (focus on the observable)
(stimuli and responses)

Cognitive revolution (theoretical / indirect measurement) (neuropsychological)

Biological revolution (discovery of genes, development of cellular / molecular techniques, imaging techniques)

Question 8

Most things we know about memory were learned from studying what ?

Answer 8

amnesic patients

Question 9

in relation to short and longterm memory what did Hebb do ?

Answer 9

distinguished between
temporary changes (electrical activity) and
permanent changes (neuronal growth)

neuronal growth = synapse remodelling, pruning etc

Question 10

Broadbent (1958) – proposed what terms

Answer 10

short term and long term memory

Question 11

describe STM ?

Answer 11

is transient

• does not require anatomical changes
• does not require new protein synthesis

Question 12

what is the fundamental difference between STM and LTM ?

Answer 12

protein synthesis

Question 13

name the categories of STM, what are they ?

Answer 13

immediate memory
- 7 items, < 30 secs (digit-span test)

working memory
- Baddeley & Hitch (1974) : ‘Three-component model of
Working Memory’
Central executive supervises flow of information from and to ‘slave’ systems (visuospatial sketchpad (facial recognition) and phonological loop ( language, sounds)

Question 14

Baddeley’s modified model of Working Memory (2000)

Answer 14

added episodic buffer - events

Question 15

what neurons are firing during the ‘Delayed matching-to-sample ‘test’ for Working Memory

Answer 15

Neurons in area TE of temporal
lobe exhibit sustained activation
(incl. during delay period)

Frontal cortex is also active

Activity in TE but not in frontal
cortex is disrupted by additional
visual stimuli during the delay period

Frontal cortex provides top-down feedback after sustaining neuronal activity across the delay period

Question 16

what is the ‘Delayed matching-to-sample ‘test’ for Working Memory

Answer 16

monkeys shown a colour , theres a deylay period of a few seconds and then they are shown 2 colours and must distinguish between the 2.

Question 17

Penfield (1940s)- stimulated medial temporal lobe what did this cause ?

Answer 17

patients to recall memories vividly

Question 18

Milner & Scoville (1950s) showed that bilateral removal of what lead to amnesia ?

Answer 18

temporal lobe
loss of capacity to form new memories
but retention of old memories, STM, learning of motor skills, performance on ‘priming tasks’

localisation of certain forms of memory
(NB. but not all) to temporal lobe

Question 19

motor learning and priming task tests what type of memory ? describe tests

Answer 19

implicit LTM

must learn how to draw a star through reflection in a mirror ( learn by repetition)

list of words given then taken away. The start of each word is given as priming inorder for patients to recall

Question 20

what do studies on HM show ?

Answer 20

Studies on HM showed that
- STM does not require the hippocampus
- LTM does require the hippocampus, but
only temporarily
- Implicit memory does not require the
hippocampus

Question 21

describe Implicit / procedural / non-declarative memory

Answer 21

how, bottom-up

• acquire motor /perceptual skills
• unconscious, automatic, reflexive, data-driven
• accumulates slowly through many trials
• does not require conscious recall
• expressed primarily in improved performance
• tied to activity of motor / sensory systems

Question 22

describe Explicit / declarative memory

Answer 22

what, top-down

• acquire factual / autobiographical knowledge
• conscious, cognitive, reflective, concept-driven
• may be established in a single trial
• requires conscious recall
• can be expressed in declarative statement
• two types: episodic (recollection) or semantic (knowledge

Question 23

two froms of LTM

Answer 23

explicit - (facts and events) medial temporal lobe

implicit - (priming) neocortex

(procedural skills and habits) striatum

(associative learning/ classical or operant conditioning) - emotional response - amygdala
skeletal musculature - cerebellum

(nonassoviative learning - habituation / sensitisation) reflex pathways

Question 24

implicit memory can be divided into ?

Answer 24

associative and non associative learning

Question 25

associative learning ? what is it dependent on ?

Answer 25

Classical conditioning (learning relationship between two stimuli) Operant conditioning (learning relationship between stimulus and own behaviour) dependent on time

Question 26

non associative learning ?

Answer 26

Habituation -in response to a repeated stimulus Dishabituation - recovery of a habituated response due to presentation of another stimulus Sensitisation -­ in response to a wide variety of stimuli following an intense noxious stimulus

Question 27

how does extinction occur in Pavlovian conditioning ?

Answer 27

Extinction occurs on repeated presentation of CS without US bell but no food

Question 28

whats Operant conditioning?

Answer 28

discovered by Thorndike, studied by Skinner - trial-and-error learning - modifies frequency of spontaneous behaviours (‘operants’) - can be rewarding or aversive (positive or negative reinforcers

Question 29

good model of implicit memory ?

Answer 29

aplysia - seasnail doesnt have hippo c so no explicit memory simple NS 20,000 =, distinct ganglia for certain behaviours

Question 30

gill-withdrawal reflex | tail-withdrawal reflex

Answer 30

gill and siphon are withdrawn after tactile or electrical stimulation of siphon tail and siphon are withdrawn after tactile or electrical stimulation of tail

Question 31

what do the snail reflexes exhibit ?

Answer 31

non-assoc learning (habituation, dishabitn, sensitisn) assoc. learning (classical & operant conditioning) STM (hours) and LTM (days to weeks) forms of each

Question 32

(habituation of gill withdrawl reflex) Repeated tactile stimulation of siphon causes ? what does this mean fro STM and LTM ?

Answer 32

decr no. of docked presynaptic vesicles of NT® decr no. of postsynaptic potentials in motor neuron ® decr gill withdrawal reflex STM (1 training sessions; learning lasts for hours) = less NT released - transcient LTM (> 4 training sessions; learning lasts several weeks) - sensory neurons retract processes and make fewer synaptic contacts on motor neurons [NB. Protein synthesis is required for LTM]

Question 33

(sensitisation of gill withdrawl reflex) Mild tail shock just before tactile stimulation of siphon causes ? is this short or longterm ?

Answer 33

``` activation of facilitatory interneurons 5-HT release onto sensory neuron activation of downstream signalling = - ­ cAMP ® ­ PKA - ­ DAG ® ­ PKC ``` multiple processes resulting in ­ increase transmitter available for release on excitation of sensory neuron = increase gill withdrawal on tactile stimulation short term sensitisation

Question 34

describe Long-term sensitisation of gill withdrawl reflex

Answer 34

(Requires training for >1 h; lasts >24 h) Persistent increases in cAMP = (i) dissociation of regulatory subunit of PKA - nuclear translocation of its catalytic subunit - phosphorylation of ApCREB1 (ii) activation of MAPK - phosphorylation of ApCREB2 (derepression) (CREB2 represses CREB1) = CREB1-dependent transcription (≥ 10 proteins)

Question 35

examples of proteins that are transcribed during long-term sensitisation ?

Answer 35

(i) ApTBL (tolloid/ BMP-1) -> activates TGFb -> activates MAPK [Sensorin (short-term effector) also activates MAPK, dependent on retrograde signal] (ii) ApUCh (ubiquitin hydrolase) -> ­ PKA -> ­ CREB1 (iii) ApCAM = new synapse growth / synaptic remodelling / neurite outgrowth

Question 36

short term changes located where | long term changes located where ?

Answer 36

short - synapse | long - cell body

Question 37

Classical conditioning of gill-withdrawal reflex? | what presynaptic events are involved ?

Answer 37

``` Tail shock (US) is paired with siphon touch (CS) so that siphon touch begins to induce gill-withdrawal ``` the US must procede the CS by 0.5s - time dependent ``` Presynaptic events: Tail shock (US) -> 5-HT release -> cAMP Siphon touch (CS) ->Ca2+ -> ­ cAMP If these are simultaneous = potentiation of PKA activation and transmitter release onto motor neuron of gill ```

Question 38

what are the postsynaptic events involved in classical conditioning of the gill withdrawl reflex ?

Answer 38

Postsynaptic events: Normally, glutamate release from siphon sensory neuron activates AMPA recs on gill motor neuron. When CS and US are paired, US depolarises motor neuron (as well as sensory neuron) removal of Mg2+ block from NMDA channel Ca2+ influx on glutamate binding positive feedback (retrograde signal) onto presynaptic neuron