title: Spatio-temporal updating in the left posterior parietal cortex.
abstract: Adopting an unusual posture can sometimes give rise to paradoxical experiences. For example, the subjective ordering of successive unseen tactile stimuli delivered to the two arms can be affected when people cross them. A growing body of evidence now highlights the role played by the parietal cortex in spatio-temporal information processing when sensory stimuli are delivered to the body or when actions are executed; however, little is known about the neural basis of such paradoxical feelings resulting from such unusual limb positions. Here, we demonstrate increased fMRI activation in the left posterior parietal cortex when human participants adopted a crossed hands posture with their eyes closed. Furthermore, by assessing tactile temporal order judgments (TOJs) in the same individuals, we observed a positive association between activity in this area and the degree of reversal in TOJs resulting from crossing arms. The strongest positive association was observed in the left intraparietal sulcus. This result implies that the left posterior parietal cortex may be critically involved in monitoring limb position and in spatio-temporal binding when serial events are delivered to the limbs.
authors: Systems Neuroscience Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.
authors: Makoto
authors: M
authors: Wada
authors: Kouji
authors: K
authors: Takano
authors: Shiro
authors: S
authors: Ikegami
authors: Hiroki
authors: H
authors: Ora
authors: Charles
authors: C
authors: Spence
authors: Kenji
authors: K
authors: Kansaku
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005123:Eye; D006801:Humans; D007600:Judgment; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000502:physiology*; D011601:Psychophysics; D012044:Regression Analysis; D013647:Task Performance and Analysis; D013997:Time Factors; D013998:Time Perception / Q000502:physiology*; D055815:Young Adult