THE PHENOMENOLOGY OF SHORT-TERM MEMORY

1. “There seems to be a presence-chamber in my mind where full consciousness holds court, and where two or three ideas are at the same time in audience, and and antechamber full of more of less allied ideas, which is situated just beyond the full ken of consciousness. Out of this antechamber, the ideas most readily allied to those in the presence-chamber appear to be summoned in a mechanically logical way, and have their turn of audience.” -- Francis Galton (1883) “The objects we feel in this directly intuited past differ from properly recollected objects. An object which is recollected, in the proper sense of the term, is one which has been absent from consciousness altogether, and now revived anew… But an object of primary memory in not thus brought back; it was never lost -- its date was never cut off in consciousness from that of the immediately present moment. In fact, it comes to us as belonging to the rerward portion of the present space of time, and not to the genuine past.” -- William James (1890) THE PHENOMENOLOGYOF SHORT-TERM MEMORY

2. MEASURING THE DURATION OF SHORT-TERM MEMORY(Peterson & Peterson, 1959) Task: rcall a 3-consonant trigram after a brief interval of distraction (so, the ‘distractor” task) . . . . . . . . . . ? XVK 294 “291, 288, uh, 285, 282..” “x,v,..g?” retention interval 3 to 18 seconds

3. MEMORY STRUCTURES AND PROCESSES INTHE “MODAL MODEL”(Atkinson & Shiffrin, 1968) SENSORY REGISTERS sensory inputs visual tactile auditory SHORT-TERM STORE (STS) temporary, working memory control processes: - rehearsal - coding - decisions - retrieval strategies LONG-TERM STORE (LTS) permanent memory store

4. CLINICAL DISSOCIATIONS of SHORT and LONG-TERM MEMORY • Damage to medial temporal lobes • Hippocampus in particular • The “classic amnestic syndrome” • HM: surgical removal • Clive Wearing: Encephalitis • Other causes of the amnestic syndrome

5. STM LTM CHARACTERISTICS OFSHORT- AND LONG-TERM MEMORY(according to the “modal model” of Atkinson & Shiffrin, 1968) • DURATION< 30 sec lifetime • CAPACITY ~7 chunks unlimited • RETRIEVAL serial parallel • FORGETTING decay, dis- interference placement • MAIN CODE acoustic- semantic articulatory

6. STM CAPACITY AND LTM CODES task: immediate serial recall (“memory span”) Miller (1956): capacity of STM as “about seven chunks” 1 4 9 2 1 7 7 6 1 9 4 5 1 9 6 3 . . . F B IJ F KF D RL B J

7. STM CAPACITY ANDREHEARSAL TIMEBaddeley et al., 1975 Number of syllables Reading Rate 1 mumps 2.2 words/sec 2 measles2.0 “ 3 leprosy 1.7 “ 4 diphtheria 1.5 “ 5 tuberculosis1.3 “ task: immediate serial recall of 6-item lists the word length effect

8. STM CAPACITY AND THE RECENCY EFFECT Task: free recall of word lists Primacy effect: better recall of first few words Recency effect: better recall of last few words Glanzer & Cunitz (1966): distraction between study and test eliminates recency effect:

9. RETRIEVAL FROM STM(Sternberg, 1966) varied set of digits held in STM 2, 5, 8, 1 test digit: is it in the set? 2 yes 7 no

10. STUDY PHASE TEST PHASE STM in the distractor task: PROACTIVE INTERFERENCEIN STM(Keppel & Underwood, 1962) things learned prior to study can proactively interfere with memory things learned between study and test can retroactively interfere with memory

11. DOMINANT CODES IN STM AND LTMBaddeley, 1966 Acoustically similar lists mad, plan, nap, bag…. Semantically similar lists big, large, huge, great… Control lists pen, day, wish, bill…. % words in correct TYPE OF SERIAL position RECALL TASK: A S C STM: 5 words, one trial, no delay __% __% 76% LTM: 10 words, four trials, delay __% __% 72%

12. DISSOCIATING VERBAL AND VISUAL SKILLSHunt, 1985 task: reading comprehension scores correlate performance with tests of... vocabulary +.67 grammar +.63 mechanical reasoning+.33 spatial thinking+.14

13. WAYS TO DISTINGUISH VERBALAND VISUAL CODES IN MEMORY • PSYCHOMETRIC • Patterns of correlations among visual and verbal tasks (e.g., Hunt, 1985) • NEUROLOGICAL • Functional asymmetries of the cerebral hemispheres: • Left H: speech and language • Right H: visual, spatial coding • Brain activity during imaging versus rehearsing • EXPERIMENTAL • Selective interference among tasks (e.g., Brooks 1968)

14. VISUAL AND VERBAL CODES IN STM (Logie, Zucco & Baddeley, 1990) • STM tasks: • Checkerboard array span • Letter list span • Concurrent tasks: • Maintain visual image • Mental arithmetic

15. “MENTAL ROTATION” OF BLOCK FORMS(Shepard & Metzler, 1971) task: decide if two figures are the same the linear function suggests a mental process that’s analogous to physical rotation

16. MENTAL ROTATION AND DEAFNESS(Emmory, Kosslyn & Bellugi, ‘93)

17. COMPONENTS OF WORKING MEMORY(Baddeley, 1990) (Random letter generation) Central executive (attentional control) Phonological loop Visual-spatial sketchpad (Repetitive articulation) (Repetitive keying)

18. WORKING MEMORY AND CHESS (Robbins, 1996) Primary task:recall of chess piece positions Secondary tasks: N None P articulate “the, the..” V execute 4x4 key pattern CE generate random letters Mean correct recall (max = 20) NP V CE

19. INDIVIDUAL DIFFERENCESIN WORKING MEMORY • Establish the “working memory span” • E.g., sentence span Up to five of:We were fifty miles out at sea before we lost sight of land.TRAIL Serial recall of final words • Correlate with target cognitive task(s) • Verbal SAT (+.59) Daneman & Carpenter ’80 • Distractibility in shadowing (Conway et al) • Interference in STM Distractor task (Engle)