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BioMed Research International
Volume 2013 (2013), Article ID 734326, 11 pages
http://dx.doi.org/10.1155/2013/734326
Research Article

The Role of Insula-Associated Brain Network in Touch

1Integrative Rehabilitation Medicine Department, National Rehabilitation Hospital, National Research Center for Rehabilitation Technical Aids, Beijing, China
2Beijing Economic and Technological Development Zone, No. 1 Ronghuazhong Road, Beijing 100176, China
3China Rehabilitation Research Center, Beijing Boai Hospital, School of Rehabilitation Medicine, Capital Medical University, Beijing 100068, China

Received 16 April 2013; Revised 9 June 2013; Accepted 24 June 2013

Academic Editor: Tonio Ball

Copyright © 2013 Pengxu Wei and Ruixue Bao. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The insula is believed to be associated with touch-evoked effects. In this work, functional MRI was applied to investigate the network model of insula function when 20 normal subjects received tactile stimulation over segregated areas. Data analysis was performed with SPM8 and Conn toolbox. Activations in the contralateral posterior insula were consistently revealed for all stimulation areas, with the overlap located in area Ig2. The area Ig2 was then used as the seed to estimate the insula-associated network. The right insula, left superior parietal lobule, left superior temporal gyrus, and left inferior parietal cortex showed significant functional connectivity with the seed region for all stimulation conditions. Connectivity maps of most stimulation conditions were mainly distributed in the bilateral insula, inferior parietal cortex, and secondary somatosensory cortex. Post hoc ROI-to-ROI analysis and graph theoretical analysis showed that there were higher correlations between the left insula and the right insula, left inferior parietal cortex and right OP1 for all networks and that the global efficiency was more sensitive than the local efficiency to detect differences between notes in a network. These results suggest that the posterior insula serves as a hub to functionally connect other regions in the detected network and may integrate information from these regions.