title: Tactile discrimination of grating orientation: fMRI activation patterns.
abstract: Grating orientation discrimination is employed widely to test tactile spatial acuity. We used functional magnetic resonance imaging (fMRI) to investigate the neural circuitry underlying performance of this task. Two studies were carried out. In the first study, an extensive set of parietal and frontal cortical areas was activated during covert task performance, relative to a rest baseline. The active regions included the postcentral sulcus bilaterally and foci in the left parietal operculum, left anterior intraparietal sulcus, and bilateral premotor and prefrontal cortex. The second study examined selective recruitment of cortical areas during discrimination of grating orientation (a task with a macrospatial component) compared to discrimination of grating spacing (a purely microspatial task). The foci activated on this contrast were in the left anterior intraparietal sulcus, right postcentral sulcus and gyrus, left parieto-occipital cortex, bilateral frontal eye fields, and bilateral ventral premotor cortex. These findings not only confirm and extend previous studies of the neural processing underlying grating orientation discrimination, but also demonstrate that a distributed network of putatively multisensory areas is involved.
authors.affiliation: Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Minming
authors.initials: M
authors.lastname: Zhang
authors.forename: Erica
authors.initials: E
authors.lastname: Mariola
authors.forename: Randall
authors.initials: R
authors.lastname: Stilla
authors.forename: Mark
authors.initials: M
authors.lastname: Stoesz
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Hu
authors.forename: K
authors.initials: K
authors.lastname: Sathian
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D010812:Physical Stimulation; D013028:Space Perception / Q000502:physiology*; D014110:Touch / Q000502:physiology*