Outline STM – WM Distinction Alan Baddeley Working Memory System

Outline

• Components of WM • WM tasks Psychology 263: Introduction to • Criticism of WM Cognitive Processes • WM & the episodic buffer • Attention & Memory Working memory • Supervisory Attentional System (SAS)

Working Memory (Baddeley, 1986; Baddeley & Hitch, 1974) STM – WM distinction

• Rationale • Short-term memory tasks • account for findings that were problematic - hold information “on-line” for the three-store model • Working memory tasks • highlight role of short-term storage in other - hold information on line and DO something cognitive tasks by introducing with that information ATTENTIONAL CONTROL e.g. mental arithmetic, random generation, reading comprehension

Alan Baddeley Working Memory System • Baddeley & Hitch (1974) • shifted the emphasis from passive storage (short-term memory) to active processing (working memory) • multiple components • Latest development: The episodic buffer

1 Working Memory Operation Working Memory Baddeley, 1986; Baddeley & Hitch, 1974 • Central Executive: directs and controls all WM functions • Visuospatial Scratchpad: a slave system (Attentional for holding visual information Control) Central Executive • Phonological Loop: a slave system for holding and recycling auditory/acoustic information – Articulatory Loop: a process for recycling, using subvocalization Phonological Loop Visuo-spatial Sketch Pad – Phonological Store: a structure for holding (verbal short-term memory) (visual short-term memory) acoustic information

Central Executive Central Executive

• Major Functions • Problem – Homunculus 1. Supply attentional resources to slave • Central Executive was initially a little man systems inside, controlling things…was actually a 2. Complex cognitive processes and placeholder in the theory and more of a decision making metaphor •Dual Task • Unfortunately, no one has ever resolved –By using tasks that require more or less exactly what the CE is (neuro evidence?) resources, experimenters can activate the Central Executive to varying degrees

Phonological Loop Articulatory Suppression

• A) Phonological Store cat • Common secondary task for investigating – temporary, passive storage dog characteristics of the slave systems – holds phoneme-based information • procedure involves repeating a word or series of – phonemic information has two words obligatory access to store – e.g. ‘the, the, the,…” or “one, two, three, • B) Articulatory Loop – active rehearsal process one,…”

– analogous to inner-speech “cat, dog, two…..” • keeps the articulatory loop busy, prevents: – “translates” written language – a) the rehearsal of new auditory verbal information – target of articulatory suppression – b) translation of visual material into phonological code

2 Evidence for the phonological loop The word length effect

• The word length effect

Run Fortuitous Tag Economy Eye Isolation Bat Dictionary Sod Educated Pill Centimeter

• Because long words take longer to rehearse they are more likely to be “forgotten”

The phonological similarity effect Patient P.V. Baddeley, 1966 • Which is easier to remember? • had a STM deficit, normal IQ, LTM, speech • immediate memory influence by BVDCGT phonological similarity with auditory RLYMXO presentation (but not visual) • does not show word length effect or • Because the phonological store is sound- disruption in articulatory suppression tasks based, items that sound the same are • a disruption of the phonological storage more likely to cause confusion component of the articulatory loop?

Visuospatial sketch pad

• Involved in manipulating visuospatial images. • Mental rotation tasks • Scanning with the minds eye • Is imagery the same as seeing? • Imagine “navigating” to Morrill Hall

3 Visuospatial sketchpad: Evidence for separate visual and Recent developments spatial components • Logie (1995) • Logie & Marchetti (1991) A) Visual Cache – temporary, passive storage – stores visual pattern information Studied Items Arm Mvmts Visual info – imagery mnemonics Spatial Patterns B) Inner Scribe Poor Good – active system Visual Patterns Good Poor – deals with spatial/movement sequences

Example of testing memory for Example of testing memory for objects, not locations objects, not locations

Memorize these objects, independent of their location Were these the three objects you just saw?

Example of testing memory for Example of testing memory for locations, not objects locations, not objects

Memorize these locations, independent of the object that Were these the locations you were asked to memorize? Occupies each location

4 Complexity effect Visual similarity effect

• Complexity of spatial patterns may be a • Walker, Hitch, & Duroe, (1993) limitation on the inner scribe – visually presented letters and digits – e.g. Cornoldi, Cortesi, & Preti (1991) – concurrent articulatory suppression = must – asked subjects to imagine paths through a rely on visual codes because no translation 5x5 matrix or a 3x3x3 matrix into phonological code • Despite the fact that they have • Tested recognition for letters and digits approximately the same number of squares, subjects find the 2 dimensional • Results: false alarms and misses to matrix easier visually similar items e.g. G 6 I 1

Bringing the components together Importance of Working Memory

• Working memory span may be a solid (Attentional predictor of people’s ability to read and Control) comprehend material Central Executive • Daneman & Carpenter (1980)

Phonological Loop Visuo-spatial Phonological store Sketch Pad Articulatory loop Inner scribe Visual cache

Working memory span WM Span

• Daneman & Carpenter (1980): presented • Daneman & Carpenter subject with a number of sentences to – Found a correlation of .72 (very high) between read out loud, and asked participants to WM and reading comprehension remember final word of each sentence – Does this mean working memory span • After all sentences, participants are asked predicts performance across a series of to recall the words in order tasks? • Is WM span correlated with reading comprehension? Test comprehension of sentences that was being read

5 The cocktail party phenomenon Conway, Cowan, Bunting 2001

• We can focus our attention on a single talker • Tested individuals working memory among a mixture of conversations and span/capacity and then subjected them to a background noises, ignoring all else “cocktail party” situation • Nonetheless, highly pertinent information can • Selective listening: Shadow a message in one capture your attention even with attempts to ear while ignoring a message in the other ignore said information • Results: only 20% of subjects with a high • In particular, one’s own name working memory capacity notice their name in • Important: Contrary to popular belief, not the unattended channel whereas 65% of everyone displays this effect (like me at subjects with low working memory capacity gatherings of my inlaws!) notice their name

Working memory… Hasher et al.

• …is critical to our ability to block out or • Garden path sentences inhibit distracting information • Before you go to bed, turn off the ______• Participant generates an item to complete the • Other evidence? sentence (e.g., lights) which the experimenter • Garden path sentences then confirms, or disconfirms and provides another possibility (e.g. stove) • Before you go to bed, turn off the ______• Memorize the last line of each sentence for later test • Are participants able to suppress the items they generated?

How do people perform on the Reasons why people like to think in later memory task? terms of WM rather than STM • People with a high working memory span • A few findings arose that were problematic do a good job of remembering the word for Atkinson & Shiffrin’s three store which correctly completes each sentence (modal) model of memory…Sensory, • People with a low working memory span STM, LTM misremember a number of the items they • The components of working memory can incorrectly generated (older individuals also) account for many of these findings • Working memory important aspect of inhibiting material and updating cognition

6 Problem #1 Problem #2

• Neuropsychological evidence • Transfer failure - Patient with small span and normal long-term – According to most models of STM, any piece memory (Warrington & Shallice, 1969) of information that remains in STM long - impairment should create a severe bottleneck enough should transfer to LTM in information transfer to long-term storage

• Solution: span depends on phonological coding • But does it….let’s try a little demonstration, while long-term memory likely depends more on draw, from memory, the following two meaning. Therefore, phonological store damage items should not affect long-term learning

Problem #3

• Working memory solution: maintenance • Some situations exist in which individuals rehearsal is accomplished via the articulatory loop. This does not necessarily result in transfer can accurately perform two tasks at the to long-term storage, it only maintains the same time (note these are not common, information in the phonological store, which does not help you in this situation but do exist) • What does lead to transfer to the long term store • If the capacity of STM is 7+ 2 items, then – Attention (really, how many of you have ever scrutinized a penny) performing two tasks simultaneously – Effort should overload the 7+ 2 rule, meaning – Levels of processing (more on this in a few performance should suffer weeks)…deeper processing leads to better recall

WM solution Evidence for this

• Dual task performance should be good if: • Visual search: thought to rely on spatial – A) the items held on-line are stored in working memory different modalities (e.g. something in the • If you provide people with a verbal or visual store, something in the phonological nonspatial visual memory load during store) visual search, search is not disrupted – B) the attentional demands don’t exceed the ability of the central executive (can’t predict • If you provide people with a spatial when this happens, we only know that working memory load, however, visual adequate performance means CE can handle search performance slows and becomes demands of tasks while poor performance more error prone means CE can’t

7 Problem for working A new component of WM memory model • Doesn’t do a good job of accounting for • The episodic buffer: A limited capacity nonverbal/nonspatial/nonvisual processing temporary storage system that is capable (taste, smell) of integrating information from a variety of • Doesn’t really provide any account of sources episodic memory • How does information from various slave systems become integrated? • Solution?

Episodic buffer - problem

• Created as an “all-purpose” response to criticisms of WM model • In this regard, it is similar to the central executive…difficult to confirm/disconfirm it’s presence, maybe more of a metaphor/homunculus • Not a lot of experimental proof for buffer and CE relative to phonological loop and visuo-spatial sketch pad

Attention and memory WM - attention Anderson & Craik, 1974 • Some researchers have claimed that working • Full attention memory and attention are the same thing – study list of 12 words • Other researchers talk about attention in more passive terms (e.g. shift your focus of attention • Divided attention to an area) with working memory being the processing/manipulating of information that is – study list PLUS reaction time task being attended – tones of different pitch, press appropriate key • In either case, any task requires – vary difficulty: 1, 2 or 3 alternatives attentional/working memory resources should impede memory performance on a secondary • Free recall task

8 Divided attention Divided Attention Anderson & Craik (1974) Anderson & Craik (1974)

9 • Normally in a divided attention task, attention is divided during encoding, 8 usually the participant is asked to split 7 attention equally between two tasks • Attention can also be divided during 6 retrieval, and we can ask subjects to

5 emphasis one task over the other

Divided attention Divided attention Anderson & Craik (1974)

Divided attention Attention

• Intentionally committing information to • Memory for new information requires attention memory requires effort and processing • Amount of attention available influences amount resources learned • Recalling information that has recently • Encoding is mostly a controlled process (though things can be transferred to LTM with little in the been placed in memory does not require a way of effort, this is not the norm) great deal of effort or resources • Effects of divided attention are minimal because (remember, recently memorized retrieval does not require a great deal of focused information is prioritized in memory) attention

9 A little bit more about WM Steps involved in routine behaviour

• Supervisory Attentional System (SAS), • 1. Sensory information enters the system Norman & Shallice, 1986 and activates several schemas (schemas – Posited to be a major component of the = stored behavioural programs associated central executive with specific stimuli) – A cognitive model for control of behaviour • 2. Contention scheduler (= automatic schema selector) selects best match – Necessary for effortful processing between stimuli and schemas • 3. Behavioural program is carried out • This is how automatic behaviour unfolds

Supervisory Attentional System Example

• SAS is required if process is NOT • Problem: Find a way to fix a candle to the wall automatic and light it without wax – A) more than one schema is appropriate (e.g. dripping to the floor water can be used to drink, wash, do dishes, • Given: Candle, matches, and a box of thumbtacks etc.) • Solution: Empty the box, – B) There is no schema associated with the tack it to the wall, place stimuli (novel situations/actions/behaviours) the candle on the box • e.g. problem solving • Have to think of the box as something other than a container

My favorite example Supervisory Attentional System

• Three men go to a motel and rent a room. The deskman charges them $30 for the room. The manager of the • SAS is required if process is NOT motel comes in and says that the deskman has charged automatic them too much, that it should only be $25. The manager then goes to the cash drawer and gets five $1.00 bills, – c) the strongest schema is inappropriate (e.g. and has the bellboy take the money back to the three men. On his way up to the room, the bellboy decides to box in previous example) give each of the men only one dollar apiece back and – d) the consequences of a wrong selection are keep the other two dollars for himself. Now that each one of the men has received one dollar back this means that dangerous (e.g. changing lanes in rush hour) they only paid $9.00 apiece for the room. So three times the $9.00 is 27.00 plus the $2.00 the bellboy kept comes to $29. Where is the other dollar? So the SAS determines controlled behaviour, • http://mathforum.org/library/drmath/view/57916.html but in many ways is another homunculus

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