title: Visual phosphene perception modulated by subthreshold crossmodal sensory stimulation.
abstract: Crossmodal sensory interactions serve to integrate behaviorally relevant sensory stimuli. In this study, we investigated the effect of modulating crossmodal interactions between visual and somatosensory stimuli that in isolation do not reach perceptual awareness. When a subthreshold somatosensory stimulus was delivered within close spatiotemporal congruency to the expected site of perception of a phosphene, a subthreshold transcranial magnetic stimulation pulse delivered to the occipital cortex evoked a visual percept. The results suggest that under subthreshold conditions of visual and somatosensory stimulation, crossmodal interactions presented in a spatially and temporally specific manner can sum up to become behaviorally significant. These interactions may reflect an underlying anatomical connectivity and become further enhanced by attention modulation mechanisms.
authors.affiliation: Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Ciro
authors.initials: C
authors.lastname: Ramos-Estebanez
authors.forename: Lotfi B
authors.initials: LB
authors.lastname: Merabet
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Machii
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
authors.forename: Gregor
authors.initials: G
authors.lastname: Thut
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Wagner
authors.forename: Vicenzo
authors.initials: V
authors.lastname: Romei
authors.forename: Amir
authors.initials: A
authors.lastname: Amedi
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
mesh_terms: D000328:Adult; D003624:Darkness; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D010719:Phosphenes / Q000502:physiology*; D012683:Sensory Deprivation / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*