Temporal structure of implicit motor imagery in visual hand-shape discrimination as revealed by MEG

• Published in: Neuroreport Vol. 9; no. 6; pp. 1127 - 1132
• Main Authors: Kawamichi, Hiroaki, Kikuchi, Yoshiaki, Endo, Hiroshi, Takeda, Tsunehiro, Yoshizawa, Shuji
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott-Raven Publishers 20-04-1998; Lippincott Williams and Wilkins
• Subjects: Adult; Anatomical correlates of behavior; Behavioral psychophysiology; Biological and medical sciences; Discrimination Learning - physiology; Fundamental and applied biological sciences. Psychology; Humans; Imagination; Magnetoencephalography; Male; Motor Cortex - physiology; Movement - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - physiology; Time Factors; Human; Mental imagery; Motor pathway; Magnetoencephalography; Central nervous system; Spatial orientation; Retinotopy; Cognition; Hand; Rotation; Information processing; Premotor cortex; Time analysis; Brain (vertebrata)
• ISSN: 0959-4965; 1473-558X
• DOI: 10.1097/00001756-199804200-00031

WE investigated the spatio-temporal brain activity on the time scale of several milliseconds related to the mental rotation task requiring judgements of hand orientation, using a whole-cortex MEG (magnetoencephalography) system. Neuronal activity in the visual cortex was observed ∼100–200 ms from stimulus onset, and that in inferior parietal lobe followed (after 200 ms). Both of these activities showed a contralateral dominance to visual stimulus hemifield. Premotor activity started later than the inferior parietal lobe activity, and these activities partially overlapped. Activity in primary motor and/or motosensory areas was observed in some subjects. The whole-cortex neuromagnetic measurements provided the time course of activity in the human brain associated with the implicit motor imageryvisual cortex ← inferior parietal lobe ↔ premotor cortex. This process is considered to be the transformation process of retinotopic locations into a body-centered reference frame necessary for the mental rotation task.