Attentional Modulation of Receptive Field Structure in Area 7a of the Behaving Monkey

• Published in: Cerebral cortex (New York, N.Y. 1991) Vol. 17; no. 8; pp. 1841 - 1857
• Main Authors: Quraishi, Salma, Heider, Barbara, Siegel, Ralph M.
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.08.2007; Oxford Publishing Limited (England)
• Subjects: Algorithms; Animals; attention; Attention - physiology; Behavior, Animal - physiology; chaos theory; cortex; Electrodes, Implanted; Electrophysiology; Extracellular Space - physiology; Macaca mulatta; Male; Microelectrodes; Models, Neurological; Neurons - physiology; Photic Stimulation; Psychomotor Performance - physiology; Regression Analysis; Retina - cytology; Retina - physiology; retinotopic map; Space Perception - physiology; spatial representation; Visual Cortex - cytology; Visual Cortex - physiology; Visual Fields - physiology; Visual Pathways - cytology; Visual Pathways - physiology; chaos theory; cortex; attention; spatial representation; retinotopic map
• ISSN: 1047-3211; 1460-2199
• DOI: 10.1093/cercor/bhl093

Spatial attention modulates the activity of inferior parietal neurons. A statistically rigorous approach to classical retinotopic mapping was used to quantify the receptive fields of area 7a neurons under 2 attentional conditions. Measurements were made with retinal stimulation held constant and the locus of attention manipulated covertly. Both tasks required central fixation but differed in the locus of covert attention (either on the center fixation point or on a peripheral square target in one of 25 locations). The neuron's identity over the recording session was confirmed using chaos theory to characterize unique temporal patterns. Sixty-six percent of the neurons changed prestimulus activity based on task state. Retinotopic mapping showed no evidence for foveal sparing. Attentional factors influenced visual responses for ∼30% of the neurons. Two types of modulation were equally observed. One group of cells had a multiplicative scaling of response, with equal instances of enhancement and suppression. A second group of cells had a complex interaction of visual and attentional signals, such that spatial tuning was subject to a nonlinear modulation across the visual field based on attentional constraints. These 2 cell groups may have different roles in the shift of attention preceding motor behaviors and may underlie shifts in parietal retinotopic maps observed with intrinsic optical imaging.