The attentional 'spotlight's' penumbra: center-surround modulation in striate cortex.
By enhancing neural activity in respective retinotopic cortical representations attention increases the efficiency with which visual information at a selected location is processed. Behavioral data also suggest that information from the vicinity of the attended region is actively suppressed. In search for a physiological correlate of this 'spotlight's penumbra' we assessed neural responses in retinotopic representations of an attended location and of locations at different distances to it. Relative to passive viewing we found suppressed striate activity for the nearby but not for the far locations. This attention-driven center-surround distribution of neural activity may enhance the contrast between attended and non-attended objects. We relate the different behavior of extrastriate areas to their lower spatial resolution, i.e. larger receptive fields.
Müller
Notger G
NG
Cognitive Neurology Unit, Dept. of Neurology, Johann Wolfgang Goethe-University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany. n.mueller@em.uni-frankfurt.de
Kleinschmidt
Andreas
A
D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*