Verbal Working Memory. The left temporoparietal junction in verbal working memory: Storage or attention. Baddelely s Multiple-Component Model

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1 Verbal Working Memory The left temporoparietal junction in verbal working memory: Storage or attention Susan Ravizza LTM vs WM Focusing on the storage component of WM Maintenance of words, pictures, goals for a short period of time Why is it important? Goals, grocery store list, problem solving If I tell you to open your book to page 105, what processes will you need to remember the page # until you flip to the correct page? Hearing Attention Sound to speech Number meaning Store speech Rehearse speech Match to book page Encoding Maintenance Retrieval Baddelely s Multiple-Component Model Baddelely s Multiple-Component Model Verbal vs spatial Incoming speech automatically gets into store If I lesion the phonological store, which processes should be intact and which impaired? For verbal STM, idea is that the store is not used for perception

2 STM Patients Patients with a verbal span of 2-3 items, intact visual working memory, no speech perception deficits Lesions are usually in superior temporal or ventral supramarginal gyrus (aka left TPJ) not in speech perception areas or primary auditory cortex fmri predictions If I compare activity in verbal vs spatial working memory, what should we observe in this left TPJ region? If I look at activity in this region, should it be active at: Encoding (when memory list is presented)? Maintenance delay (remember it for a bit)? Retrieval (asked to recall list)? What about load effects? Design Korean letters = object stimuli English letters = verbal stimuli High load = 5items Low load = 1 item Display Trial event fmri event Time 0 Design b f r c l r c x Fi Presentation Rehearsal Probe Fixation Encoding Maintenance Retrieval High load (5 items), Low load (3 items) Verbal (English letters), Objects (Korean letters) Left TPJ # #$ * -,'$ &'()* #$! $ & ' ( ($ ( (& (' $ $$ $ $& $' ) )$ ) )& )' *,-.! /01234 *,-.! :;.! / :;.! Does any region show Verbal > Object? Active during maintenance? Verbally selective Active over a delay!#$ Doesn t satisfy requirements of a short-term store Enc Mt Ret YES

3 !#$ Left Superior Temporal Gyrus Verbally selective Active over a delay # * #$ -,'$ &'()* #$! Figure 3 $ & ' ( ($ ( (& (' $ $$ $ $& $' ) )$ ) )& )' One problem: Used for speech perception Enc Mt Ret *,-.! /01234 *,-.! :;.! / :;.! Baddelely s Multiple-Component Model For verbal STM, idea is that the store is not used for perception Imaging data show this assumption of the model is wrong Conclusion Little evidence for a dedicated verbal shortterm memory buffer that is not involved in speech perception or production What about all those patients with classic short-term memory deficits? The left TPJ must be doing something important for working memory Why attention? Hearing Attention Sound to speech Number meaning Store speech Rehearse speech Match to book page Encoding Maintenance Retrieval Two types of attention: Voluntary/top down you decide what to attend Stimulus-driven attention captured

4 Attention vs. storage Stimulus-driven attention Left TPJ during encoding and retrieval because external stimuli present Right TPJ in my working memory experiment # #$ * -,'$ &'()* #$! $ & ' ( ($ ( (& (' $ $$ $ $& $' ) )$ ) )& )' *,-.! /01234 *,-.! :;.! / :;.! !#$ Enc Mt Ret Currently testing this hypothesis in my lab Study 1 Left TPJ in attention task? Use oddball task You will see a lot of signs. Raise your hand if you see something different. Did you feel like you needed short term memory to do this task?

5 Overlap of VWM and oddball Left TPJ activity is also observed in oddball tasks Currently testing this hypothesis in my lab Study 1 Left TPJ in attention task? Use oddball task So far we are seeing the left TPJ in both the oddball task and the verbal working memory task I showed you before. Red circles = VWM Blue triangles = oddball Remember this list of items: This is really the first time anyone has suggested that stimulus driven attention would HELP memory. Tomatoes Pork chops Toilet paper Oreos 60 W Light bulbs Swiss cheese Murder Vomit

6 Evil Death David These words should grab stimulus-driven attention. Studies have shown worse recall in these situations. Anyone named David? Charlie Brown Teacher effect Any speech that has been slurred from drunkenness, distorted by lousy loudspeakers, or just rendered incomprehensible by other means. Refers to the whaa-whaa-whaa trombone effect from old Peanuts TV specials, indicating when an adult was speaking Urban Dictionary Speech that does not capture your attention

7 Phonological Similarity Effect Lists of similar-sounding syllables/words are harder to recall than dissimilar-sounding syllables/words b, v, c, e vs. f, l, k, r Standard explanation is based on interference within memory sharing of phonological nodes Phonological similarity effect Stimulus-driven attention contributes to successful encoding? May help reduce PSE if we boost stimulusdriven attention to similar items? You will see two boxes on either side of the screen One box will brighten to indicate where a letter is likely to appear Tap your desk when you see a letter and also remember the letters in order D

8 B Recall the letters in the correct order - write them down Raise your hand if you put c as the third item Raise your hand if you put v as the fourth items

9 Posner cuing paradigm Valid cue = letter appears in bright box Invalid cue = letter appears opposite bright box Lists of similar and dissimilar letters Predictions Similarity effect should be abolished for invalid trials Similar items should benefit from invalid cuing Especially for later items in list when voluntary attention may wane (!'$!'!&$ Similar items are remembered betters when shown at unexpected locations (!'$!'!&!$!!#$,-.-/01 2-,,-.-/01!&$!&!$ /)0)-,1.)//)0)-,1!# ( ) * $ #!#$$&!!#$!# )*,-).,-). Stimulus-driven attention can help memory in some situations Understanding how memory works in the brain can: Help understand whether cognitive models of memory really describe how human memory works Can create new hypotheses to test such as whether stimulus-driven attention can help memory encoding