TY - JOUR
T1 - Global inhibition and stimulus competition in the owl optic tectum
AU - Mysore, Shreesh P.
AU - Asadollahi, Ali
AU - Knudsen, Eric I.
PY - 2010/2/3
Y1 - 2010/2/3
N2 - Stimulus selection for gaze and spatial attention involves competition among stimuli across sensory modalities and across all of space. We demonstrate that such cross-modal, global competition takes place in the intermediate and deep layers of the optic tectum, a structure known to be involved in gaze control and attention. A variety of either visual or auditory stimuli located anywhere outside of a neuron's receptive field (RF) were shown to suppress or completely eliminate responses to a visual stimulus located inside the RF in nitrous oxide sedated owls. The essential mechanism underlying this stimulus competition is global, divisive inhibition. Unlike the effect of the classical inhibitory surround, which decreases with distance from the RF center and shapes neuronal responses to individual stimuli, global inhibition acts across the entirety of space and modulates responses primarily in the context of multiple stimuli. Whereas the source of this global inhibition is as yet unknown, our data indicate that different networks mediate the classical surround and global inhibition. We hypothesize that this global, cross-modal inhibition, which acts automatically in a bottom-up manner even in sedated animals, is critical to the creation of a map of stimulus salience in the optic tectum.
AB - Stimulus selection for gaze and spatial attention involves competition among stimuli across sensory modalities and across all of space. We demonstrate that such cross-modal, global competition takes place in the intermediate and deep layers of the optic tectum, a structure known to be involved in gaze control and attention. A variety of either visual or auditory stimuli located anywhere outside of a neuron's receptive field (RF) were shown to suppress or completely eliminate responses to a visual stimulus located inside the RF in nitrous oxide sedated owls. The essential mechanism underlying this stimulus competition is global, divisive inhibition. Unlike the effect of the classical inhibitory surround, which decreases with distance from the RF center and shapes neuronal responses to individual stimuli, global inhibition acts across the entirety of space and modulates responses primarily in the context of multiple stimuli. Whereas the source of this global inhibition is as yet unknown, our data indicate that different networks mediate the classical surround and global inhibition. We hypothesize that this global, cross-modal inhibition, which acts automatically in a bottom-up manner even in sedated animals, is critical to the creation of a map of stimulus salience in the optic tectum.
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U2 - 10.1523/JNEUROSCI.3740-09.2010
DO - 10.1523/JNEUROSCI.3740-09.2010
M3 - Article
C2 - 20130182
AN - SCOPUS:76149096861
SN - 0270-6474
VL - 30
SP - 1727
EP - 1738
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 5
ER -