Prominent activation of the intraparietal and somatosensory areas during angle discrimination by intra-active touch

• Published in: Human brain mapping Vol. 33; no. 12; pp. 2957 - 2970
• Main Authors: Yang, Jiajia, Han, Hongbin, Chui, Dehua, Shen, Yong, Wu, Jinglong
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.12.2012; Wiley-Liss; John Wiley & Sons, Inc
• Subjects: active touch; Adult; Biological and medical sciences; Brain Mapping; Cerebellum - physiology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Discrimination (Psychology) - physiology; functional magnetic resonance imaging; Humans; index finger; intraparietal sulcus; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging; Male; Medical sciences; Nervous system; Neurology; Occipital Lobe - physiology; Parietal Lobe - physiology; passive touch; Radiodiagnosis. Nmr imagery. Nmr spectrometry; somatosensory cortex; Somatosensory Cortex - physiology; Touch - physiology; Touch Perception - physiology; Nervous system diseases; Radiodiagnosis; passive touch; Central nervous system; Finger; Nuclear magnetic resonance imaging; active touch; Encephalon; Somatosensory cortex; Discrimination; Angle; Somesthetic pathway; index finger; intraparietal sulcus; functional magnetic resonance imaging; Functional imaging
• ISSN: 1065-9471; 1097-0193; 1097-0193
• DOI: 10.1002/hbm.21419

Intra‐active touch (IAT) is a process that involves a body part doing the touching (active touch [AT]) and another body part being touched (passive touch [PT]) simultaneously. The brain representation related to IAT is still unclear. A total of 23 subjects carried out angle discrimination under PT, AT and IAT conditions with functional magnetic resonance imaging. All of the tasks were strictly dependent on cutaneous feedback from the finger(s). As the subjects were able to perceive the angle stimuli from the right (touching) and left (touched) sides during the IAT condition, we expected there would be greater brain activation with the IAT condition than for the AT or PT condition. Therefore, we hypothesized that the region within and/or around the intraparietal sulcus (IPS) and the part of the primary somatosensory cortex (SI) that is associated with high‐level tactile spatial processing would be more active during the IAT task than during the AT and PT tasks. Compared with the areas activated by the motor somatosensory control task, the most prominent activation areas evoked by the three‐angle discrimination tasks were in the SI and secondary somatosensory cortex areas in the bilateral parietal operculum, IPS, lateral occipital complex, insula and cerebellum. Finally, we directly compared IAT with AT and PT, and the results suggest that the contralateral part of IPS and part of the SI are more active under IAT conditions than under either AT or PT conditions. These results suggest that both hemispheres contribute to angle discrimination during IAT. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.