(9) Exceptional Memory Flashcards
Who was Shereshevsky (S)?
- 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
What is (S) Synaesthesia?
- S. ‘saw’, ‘felt the weight of’, and ‘tasted’ sounds and words
- S. ‘saw’ pictures when hearing or reading (abstract) words
-S’s remarkable abilities were disabling… why?
- 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
Who was Professor Aitken (Hunter, 1977)?
- 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
What was Case AJ?
- 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
What was Case HK (Ally, Hussy, & Donahue, 2012)?
- 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
Why is forgetting good?
Often forgetting is seen as a bad thing – a ‘design’ flaw
-But… > Forgetting makes traumatic and unpleasant memories less salient
What is eidetic memory?
- 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
Do chess players have eidetic memory?
- 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)
How do chess players deal with random positions?
- How do chess masters do with random chess positions?
- Not much better than amateurs (Chase & Simon, 1973; Gobet & Simon, 1996)
What was Case SF: the power of chunking (Ericsson et al., 1980)?
- 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
How might Pi be memorised?
- 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.
Example of memory techniques
- Chunking (case SF)
- Story of mnemonics (Akira Haraguchi, Tansel Ali)
- Verbal mnemonics (medical students)
What is method of loci?
-Association of to-be-remembered items with locations on a familiar route
An example of learnt good memory
- 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)
