Disclosure: We declare no conflict of interest in publishing this paper.
Distinct fine-scale fMRI activation patterns of contra- and ipsilateral somatosensory areas 3b and 1 in humans
Version of Record online: 1 APR 2014
Copyright © 2014 Wiley Periodicals, Inc.
Human Brain Mapping
Volume 35, Issue 9, pages 4841–4857, September 2014
How to Cite
Ann Stringer, E., Qiao, P.-G., Friedman, R. M., Holroyd, L., Newton, A. T., Gore, J. C. and Min Chen, L. (2014), Distinct fine-scale fMRI activation patterns of contra- and ipsilateral somatosensory areas 3b and 1 in humans. Hum. Brain Mapp., 35: 4841–4857. doi: 10.1002/hbm.22517
- Issue online: 18 JUL 2014
- Version of Record online: 1 APR 2014
- Manuscript Accepted: 17 MAR 2014
- Manuscript Revised: 12 FEB 2014
- Manuscript Received: 28 AUG 2013
- NCRR . Grant Number: IS10 RR17799
- NIBIB . Grant Number: EB002326
- NIBIB . Grant Number: EB000461
- primary somatosensory cortex;
Inter-areal and ipsilateral cortical responses to tactile stimulation have not been well described in human S1 cortex. By taking advantage of the high signal-to-noise ratio at 7 T, we quantified blood oxygenation level dependent (BOLD) response patterns and time courses to tactile stimuli on individual distal finger pads at a fine spatial scale, and examined whether there are inter-areal (area 3b versus area 1) and interhemispheric response differences to unilateral tactile stimulation in healthy human subjects. We found that 2-Hz tactile stimulation of individual fingertips evoked detectable BOLD signal changes in both contralateral and ipsilateral area 3b and area 1. Contralateral digit activations were organized in an orderly somatotopic manner, and BOLD responses in area 3b were more digit selective than those in area 1. However, the area of cortex that was responsive to stimulation of a single digit (stimulus–response field) was similar across areas. In the ipsilateral hemisphere, response magnitudes in both areas 3b and 1 were significantly weaker than those of the contralateral hemisphere. Digit activations exhibited no clear somatotopic organizational pattern in either area 3b or area 1, yet digit selectivity was retained in area 1 but not in area 3b. The observation of distinct digit-selective responses of contralateral area 3b versus area 1 supports a higher order function of contralateral area 1 in spatial integration. In contrast, ipsilateral cortices may play a less discriminative role in the perception of unilateral tactile sensation in humans. Hum Brain Mapp 35:4841–4857, 2014. © 2014 Wiley Periodicals, Inc.