Chapter 3 STM Flashcards
Digit span
Used in Wechsler
Reflects STM and WM
Memory span requires
Remembering what the items are
Remembering the order in which they were presented
Miller: number of chunks limit memory capacity.
Chunking takes cues from prosody, natural speech rhythms
Conrad: error likely to be similar in sound to item they replaced P/G/V
Phonological loop
Short-term store and articulatory rehearsal process
No explanation of how serial order stored
No clear specification of crucial processes involved in retrieval from phono store
Assume separate mechanisms
Order carried by context
Phonological similarity effect
Conrad
Letter span is reduced for similar sounding items
Suggests consistency with Conrad’s acoustic code
Big, high, tall easier - similar meaning
Phono similarity disappears if lists are increased in length and participants are allowed several learning trials
Phono coding not limited to STM. Without LTM we could never learn to pronounce new words
PSE Occurs at retrieval
Rehearsal blocked via articulatory suppression - say ‘the’ means you can’t refresh memory trace by subvocally pronouncing the membered material - prevents from being registered in phono store
Even while suppressing, people remember 4-5 visually presented digits - suggests although phono loop typically plays imp role in digit span, it’s not the only basis
With auditory presentation, words gain direct access to phono store despite articulatory suppression - similarity effect still occurs
Word length effect
Ppl remember sequences of 5 dissimilar one-syllable words relatively easily but not five-syllable words
Ppl remember as many words as they can say in 2 seconds
Longer words allow more decay to occur
Happens during subvocal rehearsal but recall phase too because they’re longer
If rehearsal prevented, word length effect should be lost
Articulatory suppression ‘the’ while performing memory task abolishes word length effect
Long words are more vulnerable to fragmentation and forgetting
Irrelevant sound effects
STM for visual digits impaired when required to ignore speech even in foreign language but not white noise
Irrelevant speech could gain access to phono store adding noise
Doesn’t matter how similar irrelevant speech is to remembered items
Vocal music disrupts not instrumental
Attributed to serial order mechanism, not phono store
Similarity between remembered and irrelevant items has no effect because they influence different parts of the system - no interaction
Changing state hypothesis
Jones and Macken
Retention of serial order can be disrupted by irrelevant stimuli, providing these fluctuate
Theories of verbal STM
Jones
Object oriented episodic record
To account for influence on STM of irrelevant sound
Sequences of items are represented as points of multimodal surface
Assumes both auditory and visual serial recall involve same system operating on common representation
Recall involves retrieving trajectory of points representing sequence
Irrelevant sounds create competing trajectories, disrupting recall
Not supported by subsequent experiments
STM theories
Nairne’s feature model
Single memory system
Each item assumed to be represented by set of features: modality dependent and independent
Hat has visually dependent features (mode, case) and independent (meaning)
Forgetting depends on interference - new items disrupt earlier features
Simulates wide range of results
Hard to explain how irrelevant sound disrupts recall after presentation of memory items, even when rehearsal is prevented by suppression
Word length effect disappears in mixed lists of long and short words
STM theories
SIMPLE
Brown Scale invariant memory Perception Learning Works for STM and LTM More distinctive items are more retrievable Not good for explaining serial recall
STM theories
Serial order in a box model
Order is maintained using an event-based context signal, with forgetting based on interference between events
Free recall
Serial position effect: last few items good - ‘recency effect’ ‘primacy effect’ less so
Glanzer: earlier items held in LTM, later STM
Recency challenged by demonstration that recency effects can occur under conditions in which the short-term trace ought to have been disrupted - counting backwards - Bjork
Baddeley rugby players
Primacy
Tendency to rehearse first few items as theyh come in
Crowder
Telephone posts along railway to recall list - closest most distinguishable from next
Visuo-spatial STM
Binding features
