Friday June 20 at 15:00 there will be a Formal Donders Colloquium given by:

Gregor Thut
(University of Glasgow)

"Inferring visual 'receptive' states from EEG and TMS"

Abstract:
There is renewed interest in the relationship between the (internal) state
of the brain before stimulus arrival and subsequent stimulus processing.
Using EEG or TMS (either alone or in combination), my aim is to study the
mechanisms that bias the visual network into one state or another,
conditioning where (spatial biases), when (speed) and whether (awareness) an
upcoming visual stimulus will be consciously perceived. My talk will focus
on changes in oscillatory EEG activity (especially in the alpha frequency
band) as a potential correlate of spontaneous and task-dependent modulations
of visual cortex activity and excitability sustaining discrete perceptual
states at baseline. I will present data on modulation of visual cortex
activity/excitability in the absence of retinal stimulation through
voluntary control (attention research), through spontaneous fluctuations
(default operation mode) and crossmodal sensory input (multisensory
research).
Overall, the data further illustrate the state-dependency of visual
perception and mechanisms for signal enhancement and inhibition.

Selected references:
Rihs TA, Michel CM, Thut G (2007) Mechanisms of selective inhibition in
visual spatial attention are indexed by alpha-band EEG synchronization. Eur
J Neurosci. 25:603-10.
Thut G, Nietzel A, Brandt SA, Pascual-Leone A (2006) Alpha-band
electroencephalographic activity over occipital cortex indexes visuospatial
attention bias and predicts visual target detection. J Neurosci.
26:9494-502.
Romei V, Brodbeck V, Michel C, Amedi A, Pascual-Leone A, Thut G (2007)
Spontaneous Fluctuations in Posterior alpha-Band EEG Activity Reflect
Variability in Excitability of Human Visual Areas. Cereb Cortex Dec 18.
[Epub ahead of print]
Romei V, Murray MM, Merabet LB, Thut G (2007) Occipital transcranial
magnetic stimulation has opposing effects on visual and auditory stimulus
detection: implications for multisensory interactions. J Neurosci
27:11465-72.

Location: Colloquium Room F.C. Donders Centre

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F.C. Donders Centre for Cognitive Neuroimaging

Visiting address:
Kapittelweg 29
6525 EN Nijmegen

Tel. 00 31 (0)24 - 3610651
Fax 00 31 (0)24 - 3610652
www.fcdonders.ru.nl