The Journal of Neuroscience, May 9, 2007, 27(19):5053-5062; doi:10.1523/JNEUROSCI.4212-06.2007
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Behavioral/Systems/Cognitive
Competitive Integration of Visual and Preparatory Signals in the Superior Colliculus during Saccadic Programming
Michael C. Dorris,1
Etienne Olivier,2 and
Doug P. Munoz1
1Department of Physiology, Canadian Institutes of Health Research Group in Sensory-Motor Systems, Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada K7L3N6, and 2Laboratoire de Neurophysiologie, Université catholique de Louvain, B-1348 Brussels, Belgium
Correspondence should be addressed to Michael C. Dorris, Department of Physiology, Room 440, Botterell Hall, Queen's University, Kingston, Ontario, Canada K7L3N6. Email: dorrism{at}biomed.queensu.ca
Efficient behavior requires that internally specified motor plans be integrated with incoming sensory information. Motor preparation and visual signals converge in the intermediate and deep layers of the superior colliculus (SC) to influence saccade planning and execution; however, the mechanism by which these sometimes conflicting signals are combined remains unclear. We studied this issue by presenting visual distractors as monkeys prepared saccades toward an upcoming target whose timing and location were fully predictable. Monkeys made more distractor-directed errors when the spatial location of visual distractors more closely coincided with the saccadic goal. Concomitant pretarget activity of SC visuomotor neurons, whose response fields were centered on the saccadic goal, was similarly increased by the presentation of nearby distractors and inhibited by the presentation of distant distractors. Finally, subthreshold microstimulation of the SC shifted the pattern of distractor-directed errors away from the saccadic goal toward that specified by the site of stimulation. Together, our results suggest that the likelihood of saccade generation is influenced by the spatial register of internal motor preparation signals and external sensory signals across the topographically organized SC map.
Key words: saccade; superior colliculus; motor preparation; motor control; sensorimotor integration; target selection
Received Sept. 26, 2006;
revised April 2, 2007;
accepted April 4, 2007.
Correspondence should be addressed to Michael C. Dorris, Department of Physiology, Room 440, Botterell Hall, Queen's University, Kingston, Ontario, Canada K7L3N6. Email: dorrism{at}biomed.queensu.ca
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R. M. McPeek
Reversal of a Distractor Effect on Saccade Target Selection After Superior Colliculus Inactivation
J Neurophysiol,
May 1, 2008;
99(5):
2694 - 2702.
[Abstract]
[Full Text]
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