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Sounds reset rhythms of visual cortex and corresponding human visual perception.

Romei V, Gross J, Thut G - Curr. Biol. (2012)

Bottom Line: In principle, this may result in stimulus-locked periodicity in behavioral performance.Here we considered this possible cross-modal impact of a sound for one of the best-characterized rhythms arising from the visual system, namely occipital alpha-oscillations (8-14 Hz).This shows that cross-modal phase locking of oscillatory visual cortex activity can arise in the human brain to affect perceptual and EEG measures of visual processing in a cyclical manner, consistent with occipital alpha oscillations underlying a rapid cycling of neural excitability in visual areas.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK. v.romei@ucl.ac.uk

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Paradigm and Results of Experiment 1Right panel shows schematic of the paradigm, illustrating TMS over occipital cortex in blindfolded participants (plus concurrent EEG recordings for experiment 2). TMS was applied at 85% of phosphene threshold, after different delays following a salient sound, or with no sound in baseline condition. Left panel shows percentage of trials with TMS-induced phosphene reported (±SEM), against delay since sound onset, for experiment 1. Leftmost point is no-sound baseline (BSL). The shaded areas (75–120 ms and 180–225 ms) represent windows of significantly increased visual cortex excitability by auditory input, i.e., phosphene rate > BSL, ∗∗p < 0.01 Bonferroni corrected. Note the periodicity of phosphene perception over time, which cycles at around 10Hz (∼100 ms peak-to-peak).
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fig1: Paradigm and Results of Experiment 1Right panel shows schematic of the paradigm, illustrating TMS over occipital cortex in blindfolded participants (plus concurrent EEG recordings for experiment 2). TMS was applied at 85% of phosphene threshold, after different delays following a salient sound, or with no sound in baseline condition. Left panel shows percentage of trials with TMS-induced phosphene reported (±SEM), against delay since sound onset, for experiment 1. Leftmost point is no-sound baseline (BSL). The shaded areas (75–120 ms and 180–225 ms) represent windows of significantly increased visual cortex excitability by auditory input, i.e., phosphene rate > BSL, ∗∗p < 0.01 Bonferroni corrected. Note the periodicity of phosphene perception over time, which cycles at around 10Hz (∼100 ms peak-to-peak).

Mentions: We hypothesized that a sound may phase-align oscillatory alpha activity over occipital areas (typically around 8–14 Hz) and thereby reveal cyclical influences of visual brain rhythms on subsequent visual processing. We tested this by assessing in two experiments reports of phosphene perception (using occipital transcranial magnetic stimulation [TMS] as in [10, 11]) at various time points after a critical sound (Figure 1, right panel) and by also measuring electroencephalography (EEG) in the second experiment.


Sounds reset rhythms of visual cortex and corresponding human visual perception.

Romei V, Gross J, Thut G - Curr. Biol. (2012)

Paradigm and Results of Experiment 1Right panel shows schematic of the paradigm, illustrating TMS over occipital cortex in blindfolded participants (plus concurrent EEG recordings for experiment 2). TMS was applied at 85% of phosphene threshold, after different delays following a salient sound, or with no sound in baseline condition. Left panel shows percentage of trials with TMS-induced phosphene reported (±SEM), against delay since sound onset, for experiment 1. Leftmost point is no-sound baseline (BSL). The shaded areas (75–120 ms and 180–225 ms) represent windows of significantly increased visual cortex excitability by auditory input, i.e., phosphene rate > BSL, ∗∗p < 0.01 Bonferroni corrected. Note the periodicity of phosphene perception over time, which cycles at around 10Hz (∼100 ms peak-to-peak).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368263&req=5

fig1: Paradigm and Results of Experiment 1Right panel shows schematic of the paradigm, illustrating TMS over occipital cortex in blindfolded participants (plus concurrent EEG recordings for experiment 2). TMS was applied at 85% of phosphene threshold, after different delays following a salient sound, or with no sound in baseline condition. Left panel shows percentage of trials with TMS-induced phosphene reported (±SEM), against delay since sound onset, for experiment 1. Leftmost point is no-sound baseline (BSL). The shaded areas (75–120 ms and 180–225 ms) represent windows of significantly increased visual cortex excitability by auditory input, i.e., phosphene rate > BSL, ∗∗p < 0.01 Bonferroni corrected. Note the periodicity of phosphene perception over time, which cycles at around 10Hz (∼100 ms peak-to-peak).
Mentions: We hypothesized that a sound may phase-align oscillatory alpha activity over occipital areas (typically around 8–14 Hz) and thereby reveal cyclical influences of visual brain rhythms on subsequent visual processing. We tested this by assessing in two experiments reports of phosphene perception (using occipital transcranial magnetic stimulation [TMS] as in [10, 11]) at various time points after a critical sound (Figure 1, right panel) and by also measuring electroencephalography (EEG) in the second experiment.

Bottom Line: In principle, this may result in stimulus-locked periodicity in behavioral performance.Here we considered this possible cross-modal impact of a sound for one of the best-characterized rhythms arising from the visual system, namely occipital alpha-oscillations (8-14 Hz).This shows that cross-modal phase locking of oscillatory visual cortex activity can arise in the human brain to affect perceptual and EEG measures of visual processing in a cyclical manner, consistent with occipital alpha oscillations underlying a rapid cycling of neural excitability in visual areas.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK. v.romei@ucl.ac.uk

Show MeSH
Related in: MedlinePlus