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This Article Full Text Full Text (PDF) All Versions of this Article: 102/3/1623    most recent 91295.2008v1 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 Google Scholar Articles by Albanese, M.-C. Articles by Duncan, G. H. PubMed PubMed Citation Articles by Albanese, M.-C. Articles by Duncan, G. H.

Differential Effects of Cognitive Demand on Human Cortical Activation Associated With Vibrotactile Stimulation

¹Department of Psychology and ²Department of Neurology and Neurosurgery, McGill University; and ³Groupe de recherche sur le système nerveux central, ⁴Département de physiologie, and ⁵Département de stomatologie, Université de Montréal, Montreal, Quebec, Canada

Submitted 12 May 2008; accepted in final form 21 June 2009

Abstract

This event-related functional MRI study examines the neural correlates of vibrotactile sensation within the context of different psychophysical demands. Nine subjects received vibrotactile stimuli on the right volar forearm during detection, localization, and passive tasks. In the detection task, subjects indicated the offset (end) of each stimulus by pressing a response key with their left hand. In the localization task, subjects identified the location of the stimulus ("distal?" or "proximal?") by pressing the appropriate response key 4 s after the end of the stimulus. In the passive task, subjects received the same vibrotactile stimuli, but no response was required. Analysis of stimulus-evoked activity compared with the resting baseline period revealed significant bilateral secondary somatosensory cortex activation for all three tasks. However, only in the offset-detection and localization tasks was stimulus-evoked activation observed in other expected areas of tactile processing, such as contralateral primary somatosensory cortex neighboring the posterior parietal cortex (SI/PPC) and in bilateral anterior insular cortex (aIC). During the localization task, we identified vibrotactile-evoked activation in the right aIC, which was maintained after the termination of the stimulus. Results suggest that vibrotactile-related activation within SI/PPC and aIC is enhanced by the increased levels of attention and cognitive demands required by the detection and localization tasks. Activation of aIC not only during vibrotactile stimulation, but also during the poststimulus delay in the localization trials, is consistent with the growing literature linking this area with the perception and short-term memory of tactile information.