HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 93/6/3659    most recent 01214.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (20) Citing Articles via Google Scholar Google Scholar Articles by Bell, A. H. Articles by Munoz, D. P. Search for Related Content PubMed PubMed Citation Articles by Bell, A. H. Articles by Munoz, D. P.

Crossmodal Integration in the Primate Superior Colliculus Underlying the Preparation and Initiation of Saccadic Eye Movements

¹Centre for Neuroscience Studies, Canadian Institutes of Health Research Group in Sensory-Motor Systems, Department of Physiology, Queen’s University, Kingston, Ontario, Canada; ²Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia; and ³Institute for Neuroscience, Department of Biophysics, Radboud University Nijmegen, Nijmegen, The Netherlands

Submitted 29 November 2004; accepted in final form 5 February 2005

Saccades to combined audiovisual stimuli often have reduced saccadic reaction times (SRTs) compared with those to unimodal stimuli. Neurons in the intermediate/deep layers of the superior colliculus (dSC) are capable of integrating converging sensory inputs to influence the time to saccade initiation. To identify how neural processing in the dSC contributes to reducing SRTs to audiovisual stimuli, we recorded activity from dSC neurons while monkeys generated saccades to visual or audiovisual stimuli. To evoke crossmodal interactions of varying strength, we used auditory and visual stimuli of different intensities, presented either in spatial alignment or to opposite hemifields. Spatially aligned audiovisual stimuli evoked the shortest SRTs. In the case of low-intensity stimuli, the response to the auditory component of the aligned audiovisual target increased the activity preceding the response to the visual component, accelerating the onset of the visual response and facilitating the generation of shorter-latency saccades. In the case of high-intensity stimuli, the auditory and visual responses occurred much closer together in time and so there was little opportunity for the auditory stimulus to influence previsual activity. Instead, the reduction in SRT for high-intensity, aligned audiovisual stimuli was correlated with increased premotor activity (activity after visual burst but preceding saccade-aligned burst). These data provide a link between changes in neural activity related to stimulus modality with changes in behavior. They further demonstrate how crossmodal interactions are not limited to the initial sensory activity but can also influence premotor activity in the SC.

This article has been cited by other articles:

				B. A. Rowland, S. Quessy, T. R. Stanford, and B. E. Stein Multisensory Integration Shortens Physiological Response Latencies J. Neurosci., May 30, 2007; 27(22): 5879 - 5884. [Abstract] [Full Text] [PDF]

				M. Avillac, S. Ben Hamed, and J.-R. Duhamel Multisensory Integration in the Ventral Intraparietal Area of the Macaque Monkey J. Neurosci., February 21, 2007; 27(8): 1922 - 1932. [Abstract] [Full Text] [PDF]

				S. Ramat, R. J. Leigh, D. S. Zee, and L. M. Optican What clinical disorders tell us about the neural control of saccadic eye movements Brain, January 1, 2007; 130(1): 10 - 35. [Abstract] [Full Text] [PDF]

				E. A. Whitchurch and T. T. Takahashi Combined Auditory and Visual Stimuli Facilitate Head Saccades in the Barn Owl (Tyto alba) J Neurophysiol, August 1, 2006; 96(2): 730 - 745. [Abstract] [Full Text] [PDF]