Transcranial magnetic stimulation: delays in visual suppression due to luminance changes.
Transcranial magnetic stimulation (TMS) was used to investigate the delays in visual processing time produced by changes in luminance. By administering a magnetic pulse over the occipital pole 80-140 ms after the onset of visual stimuli, we could suppress perception of a four-digit number within a 30 ms time window. Commensurate with previous studies of visual processing latencies, a drop in luminance from 3.52 logTd to 2.61 logTd delayed the peak of the suppression window by 8.9 ms, while a further drop from 2.61 logTD to 1.75 logTd delayed the peak by an additional 15.4 ms. This study validates the use of TMS as a psychophysical tool.
Center for Neuroscience, UC Davis, CA 95616, USA.
M B
MB
Miller
R
R
Fendrich
J C
JC
Eliassen
S
S
Demirel
M S
MS
Gazzaniga
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*