Graded Neuronal Modulations Related to Visual Spatial Attention.
Abstract
UNLABELLED:Studies of visual attention in monkeys typically measure neuronal activity
when the stimulus event to be detected occurs at a cued location versus when it occurs
at an uncued location. But this approach does not address how neuronal activity changes
relative to conditions where attention is unconstrained by cueing. Human psychophysical
studies have used neutral cueing conditions and found that neutrally cued behavioral
performance is generally intermediate to that of cued and uncued conditions (Posner
et al., 1978; Mangun and Hillyard, 1990; Montagna et al., 2009). To determine whether
the neuronal correlates of visual attention during neutral cueing are similarly intermediate,
we trained macaque monkeys to detect changes in stimulus orientation that were more
likely to occur at one location (cued) than another (uncued), or were equally likely
to occur at either stimulus location (neutral). Consistent with human studies, performance
was best when the location was cued, intermediate when both locations were neutrally
cued, and worst when the location was uncued. Neuronal modulations in visual area
V4 were also graded as a function of cue validity and behavioral performance. By recording
from both hemispheres simultaneously, we investigated the possibility of switching
attention between stimulus locations during neutral cueing. The results failed to
support a unitary "spotlight" of attention. Overall, our findings indicate that attention-related
changes in V4 are graded to accommodate task demands. SIGNIFICANCE STATEMENT:Studies
of the neuronal correlates of attention in monkeys typically use visual cues to manipulate
where attention is focused ("cued" vs "uncued"). Human psychophysical studies often
also include neutrally cued trials to study how attention naturally varies between
points of interest. But the neuronal correlates of this neutral condition are unclear.
We measured behavioral performance and neuronal activity in cued, uncued, and neutrally
cued blocks of trials. Behavioral performance and neuronal responses during neutral
cueing were intermediate to those of the cued and uncued conditions. We found no signatures
of a single mechanism of attention that switches between stimulus locations. Thus,
attention-related changes in neuronal activity are largely hemisphere-specific and
graded according to task demands.
Type
Journal articleSubject
Visual CortexNeurons
Animals
Macaca mulatta
Cues
Space Perception
Visual Perception
Attention
Male
Spatial Processing
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https://hdl.handle.net/10161/18315Published Version (Please cite this version)
10.1523/JNEUROSCI.0192-16.2016Publication Info
Mayo, J Patrick; & Maunsell, John HR (2016). Graded Neuronal Modulations Related to Visual Spatial Attention. The Journal of neuroscience : the official journal of the Society for Neuroscience, 36(19). pp. 5353-5361. 10.1523/JNEUROSCI.0192-16.2016. Retrieved from https://hdl.handle.net/10161/18315.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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J. Patrick Mayo
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