Sequences of cortical activation for tactile pattern discrimination using magnetoencephalography.
To observe sequential stages in tactile pattern discrimination and their modification with and without attention, we used whole-head anatomically constrained magnetoencephalography to spatiotemporally map brain responses. Eight, normal, right-handed participants discriminated between two patterns presented on the palm. Latencies of neural activity were determined from stimulus contact with the palm. Early cortical activation moved from sensorimotor cortex (SM1) to secondary somatosensory cortex (SII), Broca's area (BA), and superior parietal cortex by 65 ms. It continued bilaterally to temporal and frontal poles by 290 ms. Subtraction of nonattended from attended conditions removed primarily the early contralateral sensory components. There was some indication of a preferred order of sensory processing that may express and optimize hemispheric computational specializations. Results indicate similar functional organizations for tactile and visual pattern recognition.
Reed
Catherine L
CL
Department of Psychology, University of Denver, Denver, Colorado, USA. cathy.reed@cmc.edu
Hagler
Donald J
DJ
Marinkovic
Ksenija
K
Dale
Anders
A
Halgren
Eric
E
D000293:Adolescent; D000328:Adult; D000344:Afferent Pathways / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D010812:Physical Stimulation; D011930:Reaction Time / Q000502:physiology; D012867:Skin / Q000294:innervation; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D055815:Young Adult