TY - JOUR
T1 - Audio-visual synchrony and spatial attention enhance processing of dynamic visual stimulation independently and in parallel
T2 - A frequency-tagging study
AU - Covic, Amra
AU - Keitel, Christian
AU - Porcu, Emanuele
AU - Schröger, Erich
AU - Müller, Matthias M.
N1 - Funding Information:
Work was supported by the Deutsche Forschungsgemeinschaft (grant no. MU972/21-1). Data presented here were recorded at the Institut für Psychologie, Universität Leipzig. The authors appreciate the assistance of Renate Zahn in data collection. Experimental stimulation was realized using Cogent Graphics developed by John Romaya at the Laboratory of Neurobiology at the Wellcome Department of Imaging Neuroscience, University College London.
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - The neural processing of a visual stimulus can be facilitated by attending to its position or by a co-occurring auditory tone. Using frequency-tagging, we investigated whether facilitation by spatial attention and audio-visual synchrony rely on similar neural processes. Participants attended to one of two flickering Gabor patches (14.17 and 17 Hz) located in opposite lower visual fields. Gabor patches further “pulsed” (i.e. showed smooth spatial frequency variations) at distinct rates (3.14 and 3.63 Hz). Frequency-modulating an auditory stimulus at the pulse-rate of one of the visual stimuli established audio-visual synchrony. Flicker and pulsed stimulation elicited stimulus-locked rhythmic electrophysiological brain responses that allowed tracking the neural processing of simultaneously presented Gabor patches. These steady-state responses (SSRs) were quantified in the spectral domain to examine visual stimulus processing under conditions of synchronous vs. asynchronous tone presentation and when respective stimulus positions were attended vs. unattended. Strikingly, unique patterns of effects on pulse- and flicker driven SSRs indicated that spatial attention and audiovisual synchrony facilitated early visual processing in parallel and via different cortical processes. We found attention effects to resemble the classical top-down gain effect facilitating both, flicker and pulse-driven SSRs. Audio-visual synchrony, in turn, only amplified synchrony-producing stimulus aspects (i.e. pulse-driven SSRs) possibly highlighting the role of temporally co-occurring sights and sounds in bottom-up multisensory integration.
AB - The neural processing of a visual stimulus can be facilitated by attending to its position or by a co-occurring auditory tone. Using frequency-tagging, we investigated whether facilitation by spatial attention and audio-visual synchrony rely on similar neural processes. Participants attended to one of two flickering Gabor patches (14.17 and 17 Hz) located in opposite lower visual fields. Gabor patches further “pulsed” (i.e. showed smooth spatial frequency variations) at distinct rates (3.14 and 3.63 Hz). Frequency-modulating an auditory stimulus at the pulse-rate of one of the visual stimuli established audio-visual synchrony. Flicker and pulsed stimulation elicited stimulus-locked rhythmic electrophysiological brain responses that allowed tracking the neural processing of simultaneously presented Gabor patches. These steady-state responses (SSRs) were quantified in the spectral domain to examine visual stimulus processing under conditions of synchronous vs. asynchronous tone presentation and when respective stimulus positions were attended vs. unattended. Strikingly, unique patterns of effects on pulse- and flicker driven SSRs indicated that spatial attention and audiovisual synchrony facilitated early visual processing in parallel and via different cortical processes. We found attention effects to resemble the classical top-down gain effect facilitating both, flicker and pulse-driven SSRs. Audio-visual synchrony, in turn, only amplified synchrony-producing stimulus aspects (i.e. pulse-driven SSRs) possibly highlighting the role of temporally co-occurring sights and sounds in bottom-up multisensory integration.
KW - Audio-visual synchrony
KW - Brain oscillation
KW - Brain-computer interface (BCI)
KW - EEG
KW - Multisensory integration
KW - Neural rhythm
KW - Selective attention
KW - Spatial attention
KW - Steady-state response (SSR)
UR - http://www.scopus.com/inward/record.url?scp=85027520959&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2017.08.022
DO - 10.1016/j.neuroimage.2017.08.022
M3 - Article
C2 - 28802870
AN - SCOPUS:85027520959
SN - 1053-8119
VL - 161
SP - 32
EP - 42
JO - NeuroImage
JF - NeuroImage
ER -