Attention (in the visual system) RESEARCH IN COGNITIVE SCIENCE Sept. 14, 2009 S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Signe A. Vangkilde, Cand.psych., Ph.d.-stip. University of Copenhagen Center for Visual Cognition University of Copenhagen Center for Visual Cognition

Attention “Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrain state …” (James 1890, p. 247) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

A description The amount of information that impinges on our sense organs is much larger that what can be handled processed and responded to. Attention is a way of appropriately allocating our limited resources to the relevant stimuli. Attention facilitates the processing of relevant stimuli/thoughts/actions whereas irrelevant ones are ignored. S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Different kinds of attention S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN ► Attention studies use a vast number of different paradigms that mainly focus on:  Orientation of attention  Focused attention  Divided attention  Sustained attention ► However, the distinctions could be drawn differently and the experimental and theoretical tradition that scientists adhere to also counts…

Central dichotomies ► ► Automatic vs. controlled processing ► ► Early vs. late selection ► ► Parallel vs. serial processing S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Automatic  Controlled

► ► Bottom-up ► ► Exogeneous ► ► Automatic selection based on salient features:   Colour   Motion   Etc. ► ► Task inspecific S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN ► Top-down ► Endogeneous ► Voluntary selection based on current goal/task ► Task specifik

Posner’s spatial cueing paradigm (1980  ) Automatic (exogeneous) attention S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Invalid trial FixationCue Target Valid trial TIME

Posner’s spatial cueing paradigm (1980  ) Voluntary (endogeneous) attention S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Invalid trial Fixation Target Valid trial TIME Cue

S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Selection Early  Late

Classical studies ► ► Auditive attention   Cherry (1953)   Broadbent (1958)   Moray (1959)   Deutch & Deutch (1963) ► ► Visual attention   Treisman (1964)   Bundesen (1990) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Cocktail Party Effect (Cherry, 1953) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Renoir, Le Moulin de la Galette 1876

Dichotic listening / shadowing paradigms S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN ► ► Cherry (1953)   Dichotic listening: Attend to and shadow (verbally) auditive stream in one ear – ignore stimulation in the other ear   Subjects can’t report any input from the unattended ear

Early selection - Filter theory ► ► Broadbent (1958)   All information enters a sensory buffer   The physical characteristics of a stimulus decides whether it passes through the filter and is processed further   The input that is filtered out quickly decays and doesn’t put any demands on the processing resources S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Early selection, or? ► ► Moray (1959)   … but at a cocktail party we often react to our name or other subjectively relevant stimuli even though we are not attending to the source of these inputs   ”Intrusion of the unattended”   This suggests that unattended stimuli are indeed processed semantically and not just filtered on the basis of physical features S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Late selection ► ► Deutch & Deutch (1963)   Attended and ignored inputs are processed equivalently by the perceptual system, reaching a stage of semantic encoding and analysis   Only when the inputs requires a respons selection occurs  limitation concerns the amount of input that can trigger a respons   Consequence: Attention does not influence processing S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

The Attenuation Theory ► ► Treisman (1964)   Modification of Broadbent’s early selection   Deselected stimuli are not completely gated from higher analysis but merely attenuated   Attenuation = reduction in the signal strength S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Attended input Un- attended input Attenuation filter

TVA A Theory of Visual Attention Bundesen, 1990 Bundesen, Habekost & Kyllingsbæk, 2005 S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Task You will be shown a matrix of letters briefly Try to remember as many letters as possible! S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Whole Report HBCKMWLYZEXIHBCKMWLYZEXI S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Whole Report ???????????????????????? S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Sperling (1960) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Textbook model of memory S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Sensory store Short-term memory Long-term memory Decay

A Theory of Visual Attention S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Visual long term memory Visual inputs Visual short term memory RACE (between categorizations)

Processing speed in the Race Rate equation Weight equation S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Basic Assumptions of TVA ► Exponential processing ► Parallel independent processing ► Limited Visual Short-Term Memory S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Basic Assumptions of TVA ► Exponential processing ► Parallel independent processing ► Limited Visual Short-Term Memory S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Single letter identification # Identification of a single masked letter A ms S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Exponential Processing Bundesen & Harms (Psychological Research 1999) v = 77 letters/s t 0 = 19 ms P(report) = 1 – exp (- v * (t - t 0 )) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Basic Assumptions of TVA ► Exponential processing ► Parallel independent processing ► Limited Visual Short-Term Memory S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Parallel Independent Processing Kyllingsbæk & Bundesen (JEP: HPP 2007) & Bundesen, Kyllingsbæk, & Larsen (Psychonomic Bulletin 2003) ++ FP ++ TIME 29 ms500 ms KeypressReport

Basic Assumptions of TVA ► Exponential processing ► Parallel independent processing ► Limited Visual Short-Term Memory S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

The VSTM Limitation Sperling (Psychological Monographs 1960) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

KVSTM capacity (elements) CSpeed of processing (elements/s) t 0 Threshold of conscious perception (s) wAttentional weights of different locations  Relative attentional weight of distractors S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Model parameters

TVA based assessment ► Whole report: measures attentional capacity S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Whole report: General attentional capacity S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

(shown for 10 – 200 ms) S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Whole report: General attentional capacity

? S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Whole report: General attentional capacity

Example: Patient ”L4” t 0 = 24 ms C= 16 elements / s K= 3.4 elements S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN The whole report function

TVA based assessment ► Whole report: measures attentional capacity ► Partial report: measures attentional weighting S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN

Partial report: Filtering of distractors (”α”)

S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Partial report: Filtering of distractors (”α”)

S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN Bilateral displays Spatial bias of attentional weighting (”w index ”)

S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN TVA parameters KVSTM capacity (elements) CSpeed of processing (elements/s) t 0 Threshold of conscious perception (s) wSpatial bias  Distractibility

S. VANGKILDE CENTER FOR VISUAL COGNITION UNIVERSITY OF COPENHAGEN TVA-based assessment ► Duncan et al. (JEP: General, 1999) Visual neglect ► Duncan et al. (Cognitive Neuropsychology 2003) Simultanagnosia ► Habekost & Bundesen (Neuropsychologia 2003) Subclinical deficits after stroke ► Habekost & Rostrup (Neuropsychologia 2006) Right hemisphere stroke ► Peers et al. (Cerebral Cortex 2005) Parietal vs. frontal strokes ► Habekost & Rostrup (Neuropsychologia 2007) Right hemisphere stroke ► Bublak et al. (JINS 2005) Clinical testing use ► Finke et al. (JINS 2005) TVA parameters in normals ► Finke et al. (Brain 2006; Neuropsychologia 2007 ) Huntington’s disease ► Bublak et al. (Rest. Neurology & Neurosci 2006) Neurodegenerative disease ► Bublak et al. (Neurobiology of Aging, in press) Alzheimer’s and MCI ► Hung et al. (Journal of Neuroscience 2005) TMS and visual filtering ► Habekost & Starrfelt (Neuropsychologia 2006) Hemianopic alexia ► Starrfelt, Habekost, & Leff (Cerebral Cortex, 2009) Pure alexia ► Starrfelt, Habekost, & Gerlach (Cortex, 2009) Pure alexia ► Matthias et al. (JEP: HPP 2009) Cued alerting ► Matthias et al. (Neuropsychologia 2009) Vigilance