Presentation Abstract

Program#/Poster#: 800.09/KK36
Presentation Title: Perceptual awareness and selective attention differentially modulate neuronal responses in primary visual cortex
Location: Hall A-C
Presentation time: Wednesday, Nov 16, 2011, 8:00 AM - 9:00 AM
Authors: *A. V. MAIER1, M. A. COX1, E. A. REAVIS2, G. K. ADAMS3, D. A. LEOPOLD1;
1LN/ UCNI, NIH, BETHESDA, MD; 2Department: Psychological and Brain Sci., Dartmouth Col., Hanover, NH; 3Neurobio., Duke Univ., Durham, NC
Abstract: It is a common notion that perceptual awareness of sensory stimuli is tightly coupled with the focus of attention. However, under some circumstances it is possible to completely dissociate conscious perception from attentional selection (Lamme, 2003; Koch & Tsuchiya 2007). In order to investigate the neural basis of this dissociation, we have recently developed a paradigm to independently manipulate covert attention and visual awareness in non-human primates. We trained macaque monkeys to detect a slight decrement in local stimulus contrast occurring at random time intervals. In 80% of trials a preceding cue at the fixation spot indicated the correct position of the contrast change. The predictive power of the cue prompts animals to focus their attention on the cued location in visual space (Posner, 1980; Cook and Maunsell, 2002). This attentional cueing was combined with binocular rivalry flash suppression (Wolfe 1984) in order to render stimuli perceptually invisible on half of the trials. The resulting paradigm allows for independent assessment of the effects of visual awareness and attention on both the behavioral as well as the neural level. Here we present neurophysiological recordings from the primary visual cortex (V1) of two animals performing the cued flash suppression task using a linear multielectrode array. In line with previous reports, we found that the firing rate of V1 neurons was only minimally affected by binocular rivalry flash suppression (Leopold and Logothetis, 1996; Wilke et al. 2006). At the same time, local spiking activity was strongly modulated by the spatial allocation of selective attention. Whenever the animals attended toward the stimulus inside the neuron’s receptive field, there was a marked increase in activity that persisted until completion of the trial. These findings suggest that selective attention and perceptual awareness are supported by separable neuronal mechanisms that diverge at the earliest stages of cortical visual processing.
Disclosures:  A.V. Maier: None. M.A. Cox: None. E.A. Reavis: None. G.K. Adams: None. D.A. Leopold: None.
Support: Intramural Program of NIH
[Authors]. [Abstract Title]. Program No. XXX.XX. 2011 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2011. Online.

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