Selective attention contributes to global processing in vision.
Information processing is more effective within attended regions of the visual field and the size of the attended region is variable. This observation conflicts with the assumption, used in measuring the spatial extent of global integration of coherent local orientations, that optimal sensitivity to texture information is immediately available within an appropriately sized neuronal receptive field. Using extended patterns that require global processing to detect the presence of coherent orientation structure, we found that the size and topology of the region of integration of local visual cues is not fixed. Integration can occur out to a radius of at least 10 degrees, an area (314 square degrees) much larger than previously supposed, and can be constrained to annular in addition to circular apertures. The use of such spatial apertures was found to be mediated by observer expectation. The processing of texture information available in selected areas is optimized through the exclusion of noise outside the regions of interest.
Dickinson
J Edwin
JE
School of Psychology, University of Western Australia, Perth, WA, Australia. edwind@cyllene.uwa.edu.au
Broderick
Cherese
C
Badcock
David R
DR
D001288:Attention / Q000502:physiology*; D003463:Cues; D006801:Humans; D009949:Orientation; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D012684:Sensory Thresholds; D014794:Visual Fields; D014796:Visual Perception / Q000502:physiology*