The functional and temporal characteristics of top-down modulation in visual selection
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The functional and temporal characteristics of top-down modulation in visual selection. / Rose, Michael; Schmid, Carmen; Winzen, Almut; Sommer-Blöchl, Tobias; Büchel, Christian.
in: CEREB CORTEX, Jahrgang 15, Nr. 9, 09.2005, S. 1290-8.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
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TY - JOUR
T1 - The functional and temporal characteristics of top-down modulation in visual selection
AU - Rose, Michael
AU - Schmid, Carmen
AU - Winzen, Almut
AU - Sommer-Blöchl, Tobias
AU - Büchel, Christian
PY - 2005/9
Y1 - 2005/9
N2 - Perceptual load of an attended task influences the processing of irrelevant background stimuli. In a series of behavioral, functional magnetic resonance (fMRI) and electroencephalography (EEG) experiments we examined the influence of working memory (WM) load related to a relevant visual stimulus on the processing of irrelevant backgrounds. We further addressed two open questions about the mechanism of load-dependent modulation: (i) is this modulation dependent on regional activity (i.e. phasic)? (ii) At what processing stage does this modulation take place? Load was manipulated by a WM task and concurrently the processing of irrelevant visual objects was assessed with fMRI and EEG. To examine the dependency of this modulation on intrinsic activity, we varied the activity level of visual areas by presenting objects with different levels of degradation. Activity in the lateral occipital complex (LOC) increased with object visibility and was phasically modulated by WM load. Event related potentials revealed that this phasic modulation occurred approximately 170 ms after stimulus onset, indicative of an early selection under high load. The results indicate a phasic modulatory effect of WM load on visual object processing in the LOC that is comparable to the effects found for perceptual load manipulations.
AB - Perceptual load of an attended task influences the processing of irrelevant background stimuli. In a series of behavioral, functional magnetic resonance (fMRI) and electroencephalography (EEG) experiments we examined the influence of working memory (WM) load related to a relevant visual stimulus on the processing of irrelevant backgrounds. We further addressed two open questions about the mechanism of load-dependent modulation: (i) is this modulation dependent on regional activity (i.e. phasic)? (ii) At what processing stage does this modulation take place? Load was manipulated by a WM task and concurrently the processing of irrelevant visual objects was assessed with fMRI and EEG. To examine the dependency of this modulation on intrinsic activity, we varied the activity level of visual areas by presenting objects with different levels of degradation. Activity in the lateral occipital complex (LOC) increased with object visibility and was phasically modulated by WM load. Event related potentials revealed that this phasic modulation occurred approximately 170 ms after stimulus onset, indicative of an early selection under high load. The results indicate a phasic modulatory effect of WM load on visual object processing in the LOC that is comparable to the effects found for perceptual load manipulations.
KW - Adult
KW - Behavior
KW - Electroencephalography
KW - Evoked Potentials
KW - Female
KW - Frontal Lobe
KW - Functional Laterality
KW - Humans
KW - Magnetic Resonance Imaging
KW - Male
KW - Memory, Short-Term
KW - Parietal Lobe
KW - Photic Stimulation
KW - Recognition (Psychology)
KW - Visual Perception
U2 - 10.1093/cercor/bhi012
DO - 10.1093/cercor/bhi012
M3 - SCORING: Journal article
C2 - 15616129
VL - 15
SP - 1290
EP - 1298
JO - CEREB CORTEX
JF - CEREB CORTEX
SN - 1047-3211
IS - 9
ER -
