Peterson and Peterson’s (1959) experiment
Had to remember letters while counting backwards in threes for a retention interval (3-18 secs). When light went red, they had to recall the three letters. Very bad retention thus disproves unitary model of memory
Miller (1956) The magic number 7 + 2
Most people can only hold around 7 numbers in their mind at once. Disproves unitary model for memory.
Patient H.M. 1926-2008 - Henry Molaison
9yrs old - bike accident, hit head. 10yr old had seizures - kindling. Seizures got worse even on anti seizure meds. Removed medial temporal lobe bilaterally. Seizures were suppressed. Incapable of forming new episodic memory. 15-20 second max memory. Proof of seperate memory systems
Atkinson and Shiffrins (1968-71) multistore model of memory
Sensory memory (300-3000ms) - Unattenced info lost
Short term memory (20s)
- Unrehearsed info lost
Long term memory (decades) - Rehearsal/retrieval
Baddeley and Hitch (1974)
Primary task was the auditory presentation of the
word list. Secondary task was the visually presented digits - read aloud until new group. Even with high load on secondary task, results were similar. Suggests stage theory of memory does not account for rehearsal, chunking or supplementary tasks
Craik and Watkins (1973) - Maintenance rehearsal
Hold words starting with G in memory until next one
occurs. Then then hold that one etc. Poor retention to LTM - only STM. G words had poor retention.
Atkinson & Shiffrin (1971) model of memory
- Short-term and Long-term
- Transfer from STM to LTM via rehearsal.
- Retrieval from LTM back into STM.
Baddeley and Hitch, working memory model (1974)
Working memory replaces STM. This is a system with central executive, visuo-spatial sketchpad, phonological and episodic buffer.
Neuropsychological evidence from HM
Medial temporal lobe damage produces dense anterograde amnesia (LTM) with intact STM
First person to
investigate memory scientifically and systematically
Hermann Ebbinghaus (1850-1909)
Hermann Ebbinghaus forgetting curve
Given nonsense syllables to remember. After 9hrs retention level flattened out
George Sperling experiment (1960s)
12 letters flashed on screen for 50 ms. 4 letters in 3 rows. Screen goes blank. Within 250ms, tone sounded as a signal and letters from row are recalled. Usually 3/4 letters are recalled. Indicates that information is held briefly in a sensory memory
that lasts for 0.5 (vision) to 3 (auditory) seconds.
Baddeley (1966) and Conrad (1960)
Bias in encoding - phonetic (STM) vs semantic (LTM) poor memory
Stein and Bransford (1979)
What factors influence encoding in long term memory?
Asked to recall stories at a later time
- Base - 42% recall
- Base + congruent idea - 22% recall
- Base + elaboration/extra info - 74%
Participants completed the sentence in whichever way they wanted ie congruent or elaboration) - 58% recalled [91% if meaningful elaboration, 49% if not]
Craik and Tulving, 1975
Shallow processing sound of the word.
Deep processing - process the semantics of the word.
Better memory when answer is a yes - it creates deeper processing/better elaboration.
Performance increases greatly when thinking about deep processing / semantics.
Bransford and Johnson (1972)
Study looking at processing - similar to Craik and Tulving (1975)
Washing machine passage was the example given in class
- without context/uninformed - 2.8 comprehension, 13% memory.
- with context - 4.5, 32% memory of information
Conclusion - elaborative encoding improves comprehension and memory.
Elaborative processing allows prior knowledge to shape encoding.
James Macdonald
Elderly man punched so hard he passed out. Lost memory of immediately before the accident. 2008 (NZ Herald) Retrograde amnesia
Fernando Alonso (2015)
Lost 20 years of memory after the crash - believed he was a go kart racer not 2 time WC. Memory came back eventually. Retrograde amnesia.
Dresler et al (2017)
Effect of method of loci (attaching items to things in routines) training on 72 word list
- Two control groups and one contained groups
24 hrs - given list of words again and were asked to repeat after 10 minutes
Godden and Baddeley (1975)
Encoding-retrieval context. One group learnt on dry land, retrieved on dry land. One group learnt on dry land, retrieved underwater. One group learnt underwater, retrieved on dry land. One group learnt underwater, retrieved underwater. Context dependent memory
Kensinger et al (2001)
H.M was presented with a number of scenarios ie what to do if you get lost in a forest, why does land in the city cost more than in the country. He performed within 1 SD of the control mean. Ability to gain new semantic knowledge was impaired following the amnesia onset, but old semantic knowledge was intact
Mirror Drawing Task
(HM)
Visual and kinaesthetic systems are different due to the mirror. HM improved his performance and reduced mistakes as he completed the same task 24 hours apart. Even though HM couldn’t remember doing the task, he had intact skill learning.
Priming test
- Can be tested by the word fragment completion task.
- Brief presentation of a word like HARE for 35ms
- Later presentation of the word fragment eg. H_R_
- People exposed to the prime are more likely to answer HARE than non exposed controls
Misattribution - GW Bush
President GW Bush claimed to have seen both planes hit the World Trade Center, but the first plane’s impact was not broadcast. He was reading to a class of second graders when the second plane hit, so he wouldn’t have seen it on television.
