(9) Exceptional Memory

Question 1

Who was Shereshevsky (S)?

Answer 1

• Russian newspaper reporter
• Studied by Luria from 1920 to 1950
• Short-term memory span > 70 items (ten times the average person)
• Could recall lists correctly years after hearing them once
• Hadn’t taken notes, was able to repeat word for word what was said within the past hour

Question 2

What is (S) Synaesthesia?

Answer 2

• S. ‘saw’, ‘felt the weight of’, and ‘tasted’ sounds and words
• S. ‘saw’ pictures when hearing or reading (abstract) words

Question 3

-S’s remarkable abilities were disabling… why?

Answer 3

• Unable to read poetry or fiction easily
• Affected simple social interactions
• Interfered with ability to hold a regular job
• Made some money as a mnemonist
• Unable to forget – write everything he learnt on a blackboard then wiping it off
• S was eventually institutionalised

Question 4

Who was Professor Aitken (Hunter, 1977)?

Answer 4

• Mathematician
• Remarkable short-term memory span
• Retention of learned material
• Exceptional recall of material learned without intent
• Relied on conceptual mapping
• Most remarkable abilities on ‘interesting’ material, and what he had a lot of knowledge of
• Memory 2/3 times better than an average person

Question 5

What was Case AJ?

Answer 5

• Hyperthymesia
• Study of AJ implicates role for executive dysfunction
• Poor abstract reasoning
• Lack of self-generated organisation
• Poor inhibition of no-longer relevant information
• Takes away from what is going on in the moment

Question 6

What was Case HK (Ally, Hussy, & Donahue, 2012)?

Answer 6

• Normal intelligence and normal short- and long-term recall
• Increasingly accurate autobiographical memory
• Brain smaller than average
• But right amygdala 20% larger and increased connectivity to hippocampus

Question 7

Why is forgetting good?

Answer 7

Often forgetting is seen as a bad thing – a ‘design’ flaw

-But… > Forgetting makes traumatic and unpleasant memories less salient

Question 8

What is eidetic memory?

Answer 8

• Eidetic memory is not uncommon in young children
• It’s not found in adults. The only (extremely rare) exceptions may be some autistic savants, like Stephen Wiltshire (the human camera)
• Memory only limited to visual

Question 9

Do chess players have eidetic memory?

Answer 9

• Chess masters showed 91% correct recall for chess positions, compared to 41% for less expert players (De Groot, 1965)
• They rely on recognition of familiar patterns and chunking
• Typical chess master knows ≈ 50,000 chunks (Simon & Gilmartin, 1973)

Question 10

How do chess players deal with random positions?

Answer 10

• How do chess masters do with random chess positions?

- Not much better than amateurs (Chase & Simon, 1973; Gobet & Simon, 1996)

Question 11

What was Case SF: the power of chunking (Ericsson et al., 1980)?

Answer 11

• SF was a college student with an average memory (memory span of 7 digits)
• He was trained extensively to use chunking, over 230 hours
• For example, 3492 => “3 minutes and 49 point 2 seconds, near world record mile time”.
• This enabled him to increase his digit span to 79!
• His letter and word spans were no better than other people
• Specialised skill

Question 12

How might Pi be memorised?

Answer 12

• In 2006, 60-year-old Akira Haraguchi recited from memory the first 100,000 decimal places of pi
• Assigns kana symbols to digits: Example: 0 can be substituted by o, ra, ri, ru, re, ro, wo, on or oh; 1 can be substituted by a, i, u, e, hi, bi, pi, an, ah, hy, hyan, bya or byan; etc.

Question 13

Example of memory techniques

Answer 13

• Chunking (case SF)
• Story of mnemonics (Akira Haraguchi, Tansel Ali)
• Verbal mnemonics (medical students)

Question 14

What is method of loci?

Answer 14

-Association of to-be-remembered items with locations on a familiar route

Question 15

An example of learnt good memory

Answer 15

• Maguire, Valentine, Wilding, and Kapur (2003)
• In memorists, brain areas associated with location memory/navigation found to be active during memory for non-spatial stimuli
• E.g. taxi drivers. London taxi drivers show changes in hippocampal structure (Maguire et al., 2000)

Question 16

Who was Patient TT (Maguire et al., 2006) (TAXI)

Answer 16

• Just as good memory as non-brain damaged, however needs cues to take a route
• Hippocampus doesn’t acquire knowledge, uses spatial awareness

Question 17

Why does the method of loci work?

Answer 17

• Forces active thought about the material = elaborative rehearsal (relatively deep processing)
• Route provides an organisational structure
• Locations along the route function as associative cues
• Associative links are also formed between items.
• Capitalises on power of imagery (engages multiple memory codes – dual coding)
• Bizarre imagery makes the to-be-remembered information more distinctive
• When two or more items are depicted as interacting in a single image, they can be chunked as a single unit
• Re-imagining route during recall allows encoding specificity principle to be exploited