Kim Uittenhove, Lina Chaabi, Valérie Camos, Pierre Barrouillet Comparing interference patterns in working memory: An insight into domain-specific vs. domain-general maintenance Kim Uittenhove, Lina Chaabi, Valérie Camos, Pierre Barrouillet

Maintenance in working memory Domain-specific stores that contain representations tied to a particular domain (e.g., visual, auditory) Phonological loop Visuospatial sketchpad Domain-independent mechanisms that allow working-memory storage regardless of content or modality Attention Maintenance in working memory

Testing domain-general storage Testing interference when simultaneously storing information from different domains Concurrent load effects More interference = more overlap in storage mechanisms

A simultaneous maintenance paradigm Fougnie, Zughni, Godwin, and Marois (2015) 8 experiments: Basic (Expt 1) Uncommon sounds (Expts 2-3) Articulatory supression (Expt 4) Long retention interval 9s (Expt 5) With mask (Expt 6) Blocked presentation of load + reversed task order (Expt. 7) Intra-domain simultaneous maintenance (Expt. 8) Probe recognition Spatial Verbal

Sample results…

Intrinsic domain-specific storage ? No interference between the simultanous maintenance of auditory and visual material Intrinsic domain-specific storage ? Or the consequence of the paradigm ? The way recognition probes working-memory

Present study 1) The role of the paradigm: Recognition versus active recall - Recognition could rely on familiarity effects, thus rendering it more robust and operational even with less intact WM traces - Recall performance may be a more appropriate measure of an active WM system

Recognition versus recall Concurrent load interaction effects ?

Recognition (N = 24) F < 1 F < 1 F = 47.23 F = 76.93 Visual set size 1 spatial location 3 spatial location 5 spatial location Auditory set size 2 letters 6 letters F < 1 F < 1 F = 47.23 F = 76.93 Absence of concurrent load effects confirm the data of Fougnie et al. (2015)

Recall (N = 24) Visual set size 1 spatial location 3 spatial location 5 spatial location Auditory set size 2 letters 4 letters 6 letters F = 5.34 F = 26.55 F = 26.88 F = 279.93 Significant interference effects, especially of concurrent letter load on spatial location recall accuracy

Role of the paradigm Under recognition testing, there were no significant concurrent load effects. Under recall testing, there were significant concurrent load effects. 1) Interference was detected by using an active recall paradigm, but was invisible in recognition data. Simultaneous maintenance of visual and auditory information causes interference, hinting at the implication of domain-general maintenance mechanisms. 2) Understand the relative size of interference effects, and the relative implication of domain- general mechanisms Comparing interference effects

Between- versus within-domain interference Letters – spatial locations Letters-digits Ball movements – Spatial locations Letters - Letters K K K Using the same stimuli in the strong semantic overlap condition permits us to evaluate the effects of having separate presentation and response modalities, on the concurrent load effects. Between Within Strong semantic overlap

Trial letters - letters 2 auditory letters 3 visual letters

L

J

*

H

D

S

D X B F C H #

L…J… Using the same stimuli in the strong semantic overlap condition permits us to evaluate the effects of having separate presentation and response modalities, on the concurrent load effects.

A comparison of interference effects (Recall acc w/ low concurrent load – Recall acc w/ high concurrent load)/ Recall acc w/ low concurrent load (N = 24) Concurrent load effects ranging from F = 5.34 to F = 26.56 (N = 24) Concurrent load effects ranging from F = 4.25 to F = 32.44 Between- and within domain interaction effects are of comparable magnitude… Relative importance of domain-general storage mechanisms ? Visual letters (N = 18) Concurrent load effects ranging from F = 14.95 to F = 53.35 Sequential spatial locations with AS Ball movements Digits With AS, auditory letter load effects on spatial locations (19%) are 70% of auditory letter load effects on visual letters (26%)  Relatively large contribution of domain-general mechanisms in between-domain maintenance when blocking the phonological loop Strong semantic overlap lap leads to 26% reduction in recall accuracy. Role of presentation and response modality ? How to put in perspective interference effects ? Spatial locations Auditory letters Auditory letters with AS Auditory letters Spatial locations Auditory letters Strong semantic overlap

Relative importance of interference effects Effect of concurrently maintained load on recall accuracy of the memoranda Comparison to set size effects: Effect of load of the modality that is being recalled (Low load recall acc – High load recall acc) / Low load recall acc If (Interference effects == Set size effects)  adding letters in the concurrent modality has the same effect as adding them in the modality that is being recalled Set size effects = upper limit The effect of maintained memoranda load on recall accuracy of the same memoranda For example, a smaller % of auditory letters is maintained when maintaining 6 compared to 2 auditory letters

Interference effects vs set size effects Similar interference and set size effects for memoranda with strong semantic overlap (visual and auditory letters)  adding letters in the concurrent modality has the same effect as adding them in the modality that is being recalled Strong overlap in storage mechanisms, in spite of distinct presentation and recall modality Role of stimulus-specific interference ? Between-domain interference effects reach 43% of set size effects But there is also representational interference, which will be larger with letters-letters, thus enlarging set size effects Strong semantic overlap

Understanding relative size of interference effects Between-domain interference effects are relatively important (43% of set size effects) Considerable overlap in storage mechanisms ? Larger interference effects (= almost identical to set size effects) for the strong semantic overlap condition Larger overlap in storage mechanisms ? More stimulus-specific interference ?

What about recognition ? Concurrent load effects Fs < 1 (N1 & N2 = 24) (N = 9) Small tendency for interference effects, mostly not significant Lack of sensitivity of the recognition paradigm Concurrent load effects Fs ranging from < 1 to 5.71 No statistical analyses yet Auditory letters * Auditory letters Auditory letters Ball movements Digits * Spatial locations Spatial locations Visual letters Strong semantic overlap

Set size and interference effects recognition Relatively small set size effects The recognition paradigm is less sensitive to set size effects, and by consequence interference effects, which most often are not significant

Discussion Recognition paradigm seems to lack sensitivity Smaller set site effects Non-significant interference effects Possibly because it can operate on less intact memory traces and rely on familiarity effects, rendering it more robust than active recall Active recall consistently yielded interference effects Implication of domain-general maintenance mechanisms Extent of their implication ????