TEMPORARY MEMORY: SHORT-TERM AND WORKINGMEMORYLearning & MemoryArlo Clark-Foos, Ph.D.
INFORMATION PROCESSING MODELAtkinson & Shiffrin (1968)
SHORT-TERM MEMORY
Ability to store information in current consciousness without active rehearsal
Tasksn-backSerial Addition
PASAT
Working Memory?
DISTINCTIONS
Capacity
Forgetting
Components and Functions
Animal WM?
Neural representations of WM
HOW SHORT IS SHORT-TERM MEMORY?Sensory Memory
Iconic Partial Report Procedure (Sperling, 1960)< 1 sec
Echoic (Darwin et al., 1972)< 2-3 sec
SHORT-TERM MEMORY CAPACITY
Miller’s Magic Number 7 ± 2 (1956)Persecuted by a numberDigit Span
Other Span Tests (Reading, Sentence, O-Span, etc.)
Free RecallSerial Position Effects
PrimacyRecencyRole of long-term vs. short-term memory?
SERIAL POSITION EFFECTS
IMPROVING STM CAPACITY
Chunking
Ericcson, Chase, & Faloon (1980)
DURATION OF SHORT-TERM MEMORY
Brown-Peterson TaskBrown (1958) & Peterson and Peterson (1959)Forgetting CurveDecay?
FORGETTING CURVES
Different ModalitiesSimilar patterns
DURATION OF SHORT-TERM MEMORY
Proactive InterferenceKeppel & Underwood (1968)
ATKINSON & SHIFFRIN (1968): STS
SHORT-TERM VS. LONG-TERM
DistinctionsCapacityAnatomical (more later)Representational Coding
SimilarityInteractions (e.g., proactive interference)
REPRESENTATIONAL CODING
Kintsch & Buschke (1969)Serial Position & ErrorsSynonyms vs. HomophonesSemantic vs. Perceptual Similarity
ANATOMICAL DISTINCTIONS
Amnesics (Baddeley & Warrington, 1970)HippocampusH.M.Korsakoff’setc.
Temporoparietal Damage (Shallice & Warrington, 1970)No STM (recency of one), intact LTM
SHORT-TERM STORE VS. WORKING MEMORY
Baddeley (2000)
Baddeley & Hitch (1974)
Atkinson & Shiffrin (1968)
WORKING MEMORY
Baddeley & Hitch (1974)Central ExecutiveVisuospatial SketchpadPhonological Loop
Subvocal Rehearsal
Rehearsal RatesLanduer (1962)Ellis & Hennelly (1980)
Ode on WM (Keenan)
Quinn & McConnell (1996)
WORKING MEMORY
Properties of the Phonological LoopSalame & Baddeley (1987; 1989)
WORKING MEMORY
Properties of the Visuospatial SketchpadBaddeley et al. (1975)
DO ANIMALS HAVE WORKING MEMORY?Serial Probe Recognition Task (Wright et al. 1985)
NEUROLOGICAL BASIS OF WMPrefrontal Cortex (PFC)
SHORT-TERM MEMORY AND THE PFCJacobsen et al. (1937): Bilateral PFC Lesions
Delayed Response Task
FRONTAL PATIENTS
Perseverate (WCST; Roberts et al., 1996)
Proactive Interference (Shimamura et al., 1995)
Meta-Memory (underconfident JOL)
Source Memory (Dobbins et al. 2002)
Shimamura et al. (1995)
R.J. (Baddeley, 1986)ConfabulationDisexecutive Syndrome
Inability to contemplate current and recalled events or to interpret the validity and implications of those experiences to draw reasonable conclusions
PFC CONNECTIONS
InputDLPFC
SomatosensoryVisualspatial“Where”
LPFCAuditory, Olfactory, Taste, and Visual Pattern Information“What”
IT’S A BIG PFC AFTER ALL
Not just one big lump of grey matter…
Lateralized (Smith et al., 1996)n-back task (Spatial vs. Verbal)
SMITH ET AL.’S (1996) N-BACK TASKS
Baddeley & Hitch (1974)
Smith, Jonides, & Koeppe (1996)
Right Hemisphere
Left Hemisphere(Broca’s area?)
SHORT-TERM MEMORY AND THE PFCJacobsen et al. (1937): Bilateral PFC Lesions
Delayed Response Task
Lesion to ____ affected ______:
DLPFC Spatial WMLPFC Object MemoryOPFC Sensory Discriminations
~ in other species too (Kolb & Robbins, 2003)
TASK SWITCHING AND PRODUCTION RULES
Intra vs. Extradimensional Shifts (Dias et al. 1996)
Reward Contingencies
New Production Rule
DELAY CELLS
Fuster (1995)Goldman-Rakic (1995)
Occular motor delayed response taskDLPFC lesion
mnemonic scotoma
CATEGORICAL PERCEPTION (FREEDMAN ET AL., 2001)
Firing rate of cells in PFC
WORKING MEMORY LOAD
Cohen et al. (1997): n-back (0,1,2,3)
WORKING MEMORY LOAD
Cohen et al. (1997): n-back (0,1,2,3)
PFC: Active throughout delayVisual Area: Active late in delayBroca’s Area: Greatest activation for high load at high delay
PFC-HIPPOCAMPUS INTERACTIONS
PFC-HIPPOCAMPUS INTERACTIONS