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) A corrigendum has been published All Versions of this Article: 97/1/264    most recent 00617.2006v1 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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Li Hegner, Y. Articles by Braun, C. Search for Related Content PubMed PubMed Citation Articles by Li Hegner, Y. Articles by Braun, C.

BOLD Adaptation in Vibrotactile Stimulation: Neuronal Networks Involved in Frequency Discrimination

¹Institute of Medical Psychology and Behavioral Neurobiology, ²MEG-Center, ³Graduate School of Neural and Behavioural Sciences, International Max Planck Research School, and ⁴Neuroradiology, University Clinics Tübingen, University of Tübingen, Tübingen, Germany; and ⁵Department of Psychiatry and Psychotherapy, University Hospital Aachen, Aachen, Germany

Submitted 13 June 2006; accepted in final form 19 October 2006

The present functional magnetic resonance imaging (fMRI) study investigated human brain regions subserving the discrimination of vibrotactile frequency. An event-related adaptation paradigm was used in which blood-oxygen-level-dependent (BOLD) responses are lower to same compared with different pairs of stimuli (BOLD adaptation). This adaptation effect serves as an indicator for feature-specific responding of neuronal subpopulations. Subjects had to discriminate two vibrotactile stimuli sequentially applied with a delay of 600 ms to their left middle fingertip. The stimulus frequency was in the flutter range of 18–26 Hz. In half of the trials, the two stimuli possessed identical frequency (same), whereas in the other half, a frequency difference of ±2 Hz was used (diff). As a result, BOLD adaptation was observed in the contralateral primary somatosensory cortex (S1), precentral gyrus, superior temporal gyrus (STG); ipsilateral insula as well as bilateral secondary somatosensory cortex and supplementary motor area. When statistically comparing the BOLD time courses between same and diff trials in these cortical areas, it was found that the vibrotactile BOLD adaptation is initiated in the contralateral S1 and STG simultaneously. These findings suggest that the cortical areas responsive to the frequency difference between two serially presented stimuli sequentially process the frequency of a vibrotactile stimulus and constitute a putative neuronal network underlying human vibrotactile frequency discrimination.