On the specificity of neuronal oscillations in human visual cortex

Abstract

Oscillatory neural activity plays an important role in cognition. In this combined EEG/fMRI study we explore the spatial and representational specificity of oscillatory activity in alpha (8-12 Hz) and gamma (30-90 Hz) frequency bands in human visual cortex by means of a localiser-based analysis of fMRI data. These frequency bands are thought to represent the functional inhibition of brain areas and the representation of a stimulus, respectively. In line with the functional specialisation of oscillatory frequency bands, it may be expected that alpha activity is more global than gamma activity, which in turn is expected to be representationally specific. In this thesis, an experimental and analysis pipeline is described which allows for testing this hypothesis. Pilot results are; shown which demonstrate that stationary gratings can be used for the elicitation of gamma components in fMRI/EEG analysis and demonstrate that the parameters determined by means of two EEG pilot experiments can be validly transferred to an EEG/fMRI context.