Lecture 5: Memory Systems

Question 1

Sensory Memory

Answer 1

=the ability to retain impressions of sensory information after the original stimuli have ended

Question 2

Sperling 1960

Answer 2

• Using a chart participants were asked to look at the chart for less than a second and were asked to recall how many of the letters they could remember.
• Then participants had to recall single rows of letters when particular tones were heard.
• High tone for top row, medium tone for middle row and low tone for the bottom row.

Results

• participants could remember approximately 4/5 letters although they were aware of more.
• on average 3 times were recalled from the indicated row.

Conclusion
- In theory the participants should remember more than 4 items which is the average. It’s believed that the image of each item fades and so does the time taken to remember the recalled items.

• Need to attend to information to be able to recall it
• Sensory memory very brief, attention required, then can hold info and transfers to STM
• Only things attend to transferred to STM

Question 3

STM

Answer 3

• 3-4 pieces of information
• limited duration/capacity

-‘chunking’ important in determining ‘capacity’: the more you can link things together the more can remember

Question 4

Peterson and Peterson (1959)

Answer 4

Procedure:
A lab experiment was conducted in which 24 participants (psychology students) had to recall trigrams (meaningless three-consonant syllables, e.g. TGH, CLS).

The trigrams were presented one at a time and had to be recalled after intervals of 3, 6, 9, 12, 15 or 18 seconds.

To prevent rehearsal participants were asked to count backwards in threes or fours from a specified random number until they saw a red light appear. This is known as the brown peterson technique.

Findings:
There was a rapid increase in forgetting as the time delay increased.

After 3 seconds 80% of the trigrams were recalled correctly.
After 6 seconds this fell to 50%.
After 18 seconds less than 10% of the trigrams were recalled correctly.
Conclusion:
Short-term memory has a limited duration when rehearsal is prevented. It is thought that this information is lost from short-term memory from trace decay.

The results of the study also show the short-term memory is different from long-term memory in terms of duration. Thus supporting the multi-store model of memory.

Question 5

Multi-store model of memory

Atkinson and Shiffrin (1968)

Answer 5

But…..
¥ Learning depends on how material is processed, rather than time in short-term storage (Craik & Lockhart, 1972)
¥ No. of patients have severe STM deficits without clear LTM deficits
¥ Simple storage does not tell the whole story…

More you think about learning more you are likely to remember something
Understanding meaning and links between ideas allows memories to be transferred into LTM

Question 6

Working memory

Answer 6

=STM plus processing
Important for huge range of abilities eg education attainment (Gathercole et al 2008)

Question 7

Primacy and Recency

Postman and Phillips (1965)

Answer 7

Remember 1st few and last few, lose the ones in the middle
Delay doesn’t eliminate recency effect

• Baddeley and Hitch 1977, Baddeley 1991
• Temporal discrimination (Crowder, 1976)

Question 8

Neuropsychological double-dissociations

Answer 8

• can infer partial independence of cognitive functions underlying 2 cognitive tasks
• helps to rule out task difficulty as explanation

Question 9

H.M

Answer 9

e.g. Scoville & Milner, 1957; Milner, 1966)
¥ Bilateral damage to hippocampus & MTL
¥ Severe anterograde amnesia
¥ Limited, temporally graded retrograde amnesia
¥ Spared Digit span, Peterson performance, Recency in free recall

Question 10

H.M

Answer 10

e.g. Scoville & Milner, 1957; Milner, 1966)
¥ Bilateral damage to hippocampus & MTL
¥ Severe anterograde amnesia
¥ Limited, temporally graded retrograde amnesia
¥ Spared Digit span, Peterson performance, Recency in free recall

Question 11

Patient KF

Answer 11

showed opposite pattern of memory problems, completing double dissociation between STM & LTM:
¥	 Impairments in:
¥	 Peterson task (STM)
¥	 Other STM tasks
¥	 Recency in free recall
¥	 Spared ability for:
¥	 LTM tasks

Question 12

Episodic memory

Answer 12

¥ Remembering that the word ‘elephant’ was presented in a studied list of words
¥ Remembering getting your A level results

*recall of personal facts

Question 13

Semantic memory

Answer 13

¥ Knowing that elephants live in Africa
¥ Knowing your A-level results

*recall of general facts

Question 14

Flash bulb memory

Brown and Kulik, 1977

Answer 14

¥ Finkenauer et al. (1998) studied death of King of Belgium
¥ Proposed emotional-integrative model: surprise, emotionality, and personal importance of event determine efficient encoding & later rehearsal.
¥ Produces detailed & durable representations

¥ Prone to information loss & error like any other memory (Schmolk et al., 2000; Wright et al., 1998)
¥ Hirst et al. (2015)
¥ Surveys at 1 wk, then 11, 25, & 119 months later
¥ Rapid forgetting only in 1st year
¥ Inconsistent memories often repeated in later surveys, unless corrected by media

*whats important is peoples confidence in their memory not accuracy which seems to decay in the same way as normal memories