Direction of cross-modal information transfer affects human brain activation: a PET study.
The purpose of this study was to determine the functional organization of the human brain involved in cross-modal discrimination between tactile and visual information. Regional cerebral blood flow was measured by positron emission tomography in nine right-handed volunteers during four discrimination tasks; tactile-tactile (TT), tactile-visual (TV), visual-tactile (VT), and visual-visual (VV). The subjects were asked either to look at digital cylinders of different diameters or to grasp the digital cylinders with the thumb and index finger of the right hand using haptic interfaces. Compared with the motor control task in which the subjects looked at and grasped cylinders of the same diameter, the right lateral prefrontal cortex and the right inferior parietal lobule were activated in all the four discrimination tasks. In addition, the dorsal premotor cortex, the ventral premotor cortex, and the inferior temporal cortex of the right hemisphere were activated during VT but not during TV. Our results suggest that the human brain mechanisms underlying cross-modal discrimination have two different pathways depending on the temporal order in which stimuli are presented.
Kawashima
Ryuta
R
NICHe, Tohoku University, Aramaki, Aoba, Aobaku, Sendai 980-8579, Japan. ryuta@idac.tohoku.ac.jp
Watanabe
Jobu
J
Kato
Takashi
T
Nakamura
Akinori
A
Hatano
Kentaro
K
Schormann
Torsten
T
Sato
Kazunori
K
Fukuda
Hiroshi
H
Ito
Kengo
K
Zilles
Karl
K
D000328:Adult; D004192:Discrimination, Psychological; D006801:Humans; D009044:Motor Cortex / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D011597:Psychomotor Performance; D012016:Reference Values; D012858:Size Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology; D014055:Tomography, Emission-Computed; D014110:Touch / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*