title: The effect of TMS on visual motion sensitivity: an increase in neural noise or a decrease in signal strength?
abstract: The underlying mechanisms of action of transcranial magnetic stimulation (TMS) are still a matter of debate. TMS may impair a subject's performance by increasing neural noise, suppressing the neural signal, or both. Here, we delivered a single pulse of TMS (spTMS) to V5/MT during a motion direction discrimination task while concurrently manipulating the level of noise in the motion stimulus. Our results indicate that spTMS essentially acts by suppressing the strength of the relevant visual signal. We suggest that TMS may induce a pattern of neural activity that complements the ongoing activation elicited by the sensory signal in a manner that partially impoverishes that signal.
authors.affiliation: Department of Neurological, Neuropsychological, Morphological and Motor Sciences, University of Verona, Verona, Italy. manuela.ruzzoli@cognitiveneuroscience.it
authors.forename: Manuela
authors.initials: M
authors.lastname: Ruzzoli
authors.forename: Arman
authors.initials: A
authors.lastname: Abrahamyan
authors.forename: Colin W G
authors.initials: CW
authors.lastname: Clifford
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Marzi
authors.forename: Carlo
authors.initials: C
authors.lastname: Miniussi
authors.forename: Justin A
authors.initials: JA
authors.lastname: Harris
mesh_terms: D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology / Q000528:radiation effects; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology / Q000528:radiation effects*; D011597:Psychomotor Performance / Q000502:physiology / Q000528:radiation effects; D015398:Signal Transduction / Q000528:radiation effects; D050781:Transcranial Magnetic Stimulation; D014793:Visual Cortex / Q000502:physiology / Q000528:radiation effects*; D055815:Young Adult