consolidation and forgetting

Question 1

define forgetting

Answer 1

“inability to recall something that could be remembered previously”

NOT failure to encode ( must have been formed to forget it)

Question 2

what is inaccessibility

Answer 2

when a cue is needed to retrieve memory but is not provided

can’t be disproved

Question 3

Ebbinghaus and rate of forgetting

Answer 3

info rapidly forgotten initially then rate slows

Question 4

Ebbinghaus 1885 Nonsense syllable experiment

Answer 4

results of which creates the forgetting curve

Question 5

4 explanations of forgetting

Answer 5

trace decay (mems fade over time)
interference (mems get confused, esp if similar)
cue dependent forgetting (issue of accessibility  & not availability)
consolidation (new mems= fragile)

Question 6

problems with trace decay

Answer 6

average % correct decreased after 18 secs

BUT little forgetting in Peterson and peterson’s 1st trial

Question 7

Trace decay

Brown - Peterson 1958 trigrams

Answer 7

presented w/ 3 consonant trigrams
counts backwards in 3's 
0s delay = 90% correct recall 
18s delay = 7% recall 
retention duration = 20s

Question 8

trace decay

Baddeley et al 1975 ( word length effect)

Answer 8

more time elapses for longer words before rehearsal = longer words forgotten to greater extent

Question 9

trace decay

phonological loop Baddeley & Hitch ‘74

Answer 9

w/out rehearsal phonological info fades from store

Question 10

what is interference

Answer 10

ability to remember current info = disrupted by previous/future learning
more sim mems = greater confusion

Question 11

2 types of interference

Answer 11

Proactive = old info interferes w/ learning new info 
retroactive = new info interferes w/ retention of old

Question 12

Retroactive Interference evidence
Waugh & Norman probe digit task
implications for decay account

Answer 12

hear 16 digits and last digit tells u which to report (go back to last occurrence and list no. after)
manipulates how much intervening info before making report
Performance same w/ 1 no. per sec & 4 no.’s per sec.
Decay account should have resulted in poorer performance for the slower 1 per sec condition.

Question 13

Proactive interference evidence

Wickens et al 1976 (3 words then count backwards 15s before recall)

Answer 13

4 trials w/ diff words
words from new cat = release from PI
(e.g fruit & professions)
profession words more distinct = release from PI

Question 14

Problems w/ interference

Answer 14

doesn’t explain ebbinghaus curve (slows over time) even as more interference shld = accelerated forgetting
Overlap w/ other accounts (time based decay & cue dependency)

Question 15

what is cue dependent forgetting

Answer 15

failure to retrieve memory as appropriate cue not presented

non- falsifiable as potential infinite no. of cues

Question 16

Search engine analogy (CDF)

Answer 16

searching for item online

exists but can only find w/ right search term

Question 17

Meeter et al (2005)
forgetting curve for newsworthy events
MCQ’s vs free recall

Answer 17

found perfromance better for MCQ’s (52%) than free recall (31%)
MCQ answer options = cue

Question 18

Tulving and Pearlstone (1966)

recall w/ cues vs free recall

Answer 18

found w/ cues recall double the words

supports as shows mem exists just needs right cue

Question 19

meaning of the Ebbinghaus curve

Answer 19

shape indicates forgetting slows over time (mems become more stable/ less fragile)

Question 20

what are the 2 types of consolidation

Answer 20

synaptic = changes in connectivity b/w neurons (occurs rapidly) 
systemic = mems become independent from hippocampus & move to surrounding cortices  (more long term process

Question 21

Hebb ‘48

what is info storage at synapse

Answer 21

learning & mem repped in brain by physiological changes @ synapse
neural record of experience ( cells fire together wire together)

Question 22

Info storage @ synapse

Long term potentiation (LTP)

Answer 22

repeated stimulation = enhanced neuron firing

structural changes & enhanced responding ( neurons in hippocampus, amygdala & cortex show LTP after learning ep.

Question 23

what happens in mind-mem consolidation

Answer 23

mem for recent events = fragile
if disrupted recent mems won’t consolidate
new info & protein inhibitors can interfere w/ mem consolidation
sleep can aid process

Question 24

behaviour approach
Muller & Pilzecker 1900
effect of delay on mem consolidation

Answer 24

p's learn 2 lists of words 
IV - group 1 learn 2nd list immediately,
group 2 learn after 6 min delay 
DV - mem recall for 1st list, 
immediate = 28%
delay = 48%

Question 25

behaviour approach
Gais et al 2007
effect of sleep on mem consolidation (fMRI study)

Answer 25

IV - group 1 = learn list shortly before sleep
group 2 = learn hours before sleep
DV - % words forgotten 2 days later 
sleep = 0.5%
awake = 16%
different brain activity b/w groups

Question 26

what interferes w/ synaptic consolidation

Answer 26

sleep (but not if REM)
Post trial alcohol (reduces RI rather than facilitating consolidation)
suggests new mems interfere w/ synaptic consolidation process

Question 27

Anterograde amnesics & consolidation

Answer 27

some capable of long-term retention when interference minimised

Question 28

Cowan et al 2004 recall after different intervals

Anterograde & consolidation

Answer 28

Cowan et al. (2004)
6 densely amnesic given a list of 15 words to remember
Recall test was (i) immediately, (ii) following an unfilled interval, or (iii) following a filled interval
4/6 patients had better mem following the unfilled 10 min interval

Question 29

Dewar et al 2009 early and later interference

Anterograde & consolidation

Answer 29

if p’s rehearsing in STM shld be no diff b/w early & late interference ( 1st & last 3 mins)
Performance best when no interference but also better when interference in the last 3 minutes
inconsistent w/ absence of LTM

Question 30

Dewar et al 2009 retroactive interference effects

implications

Answer 30

patients more susceptible to RI effects
Explains why mem better when interference occurred later: provided opp to consolidate learning
More forgetting when interference is immediately after learning = synaptic consolidation is disrupted

Question 31

New cog model of forgetting

Answer 31

explains anterograde amnesia by depletion in consolidation resources

Question 32

Anterograde Traumatic Brain Injury Consolidation Failure

Yarnell and Lynch, 1970 (american football players)

Answer 32

Remembered the incident when leaving the field but could not recall it later = Failure to consolidate

Question 33

Yarnell and Lynch, 1970 implications of anterograde amnesia

Answer 33

In anterograde amnesia, mems can be preserved if interference reduced ( allowing more efficient synaptic consolidation)

Question 34

Retrograde Amnesia

Patient PZ

Answer 34

Patient PZ had just completed his memoirs prior to amnesia= good source for checking mem loss (Zola-Morgan et al., 1983)
Older memories more resilient than recent memories
Found for both semantic and episodic mems (Mann et al., 2003; Bayley et al., 2006)

Question 35

Retrograde Amnesia: Systemic Consolidation

Answer 35

Temporally graded amnesia (greater loss for more recent memories) is consistent with systemic consolidation
Assumes that hippocampus and associated areas operate as an intermediate storage structure
Older memories get moved into the neocortex (outer layer of brain)
Therefore, damage to the hippocampus (and/or associated areas or connections) affects new memories
Older memories survive as not hippocampal-dependent