Frequency and Laminar Profile of Feature Specific Visual Activity Revealed by Interleaved EEG-fMRI

The role of cortical oscillations in brain function has been extensively debated, resulting in a variety of theoretical frameworks. Using interleaved simultaneous EEG-fMRI, we examined the layer-specific relationship between oscillatory activity and visual processing. We could demonstrate that γ-band activity positively correlates with feature specific signals in superficial layers, but we were able to report a deep layer contribution as well. In addition, we could demonstrate that α-band power not only correlates negatively with the feature unspecific BOLD signal, but related to feature specific BOLD as well. Lower frequency α was predominantly related to feature unspecific superficial layer BOLD, while upper frequency α was found to be related to feature specific BOLD in superficial and deep layers. We conclude that the role of α-band oscillations extends beyond widespread inhibition and might be involved in active stimulus processing to the level of visual features.