Models of attention and memory (to be done in Semester 2):
Frederic Bartlett's (1932) idea that schemata help organise memory (see sec. influenced David Broadbent as well as George Miller. His work was explicitly anti-Ebbinghaus:
Cherry and Broadbent (1950s): Capacity to attend to and obtain information from noisy data. Asked subjects to concentrate on information going into one ear. Found that information into the other ear was then not attended, but its gross characteristics - music or speech were detected. Proposed three types of memory stores.
Broadbent's information processing diagram (Gardner MNS, p.92)
Neville Moray (1969) If an unattended message is prefaced by one's name one does obtain information from it.
Anne Treisman (1960, 1964) If identical messages are presented to both ears without warning, the subject detects this, showing that informative aspects of the message are detected bi-aurally. Subject can also shift attention from one ear to another. Thus the filter is not an all-or-none switch but a means of attenuating some signals.
Ulric Neisser developed this idea into sensory register, short-term store and long-term store. (To do in Semester 2)
G. Sperling's (1960) evidence for sensory store: 3X3 array of letters presented for 50 msec. Recall is normally 4-5 letters (1-2 per row). But if one row is cued by a tone exactly when the array is turned off, the subjects can still ``see'' it briefly and report all 3 letters. If the cue is delayed for a split second, the image in the sensory store is partly decayed and recall is less. At a delay of 1 second, decay is complete.
Peterson and Peterson's (1959) evidence for short term store: Presented 3 consonants to subjects (well within memory span). Before recall the subjects were asked to count backwards by 3's for periods from 3 to 18 secs. Ability to recall the consonents dropped sharply after between 3-9 seconds of delay.
Another technique to prevent rehearsal was used by Waugh and Norman (1965). Subjects heard 15 digits and then, probed with one digit, tried to recall the digit following. The further back the probe was in the sequence, the poorer was the performance. W&N attributed this to later digits replacing the earlier ones in ST store.
(A&S had earlier suggested a decay of STM. W&N's expt suggested replacement - details on net - to do in Semester 2)
Long term store: (acc. W&N) When subjects have time to rehearse an item it has a chance of being retained in STM and also being added to LTM. In general the ST store has an auditory character while the LTS is meaning-based. Baddeley (1976) also included a visual STS.
William James had much earlier talked of primary and secondary memories. W&N added to it an experimental technique, a theory about rehearsal, and a mathematical model in which the probabilities of retreival from the two stores were (statistically?) independent.
Atkinson and Shiffrin's (1968) model. Made a distinction between fixed and flexible structures. Sensory registers, STS and LTS are fixed. Control processes like attention, rehearsal and retrieval act on the fixed structures. Attention determines transfer or not from SR to STS, rehearsal determines STS to LTS. Loss from STS is due to decay or replacement. LTS suffers no loss - forgetting is due to failure of retreival. (see mathematical/ predictive aspects of the model)