Neural mechanisms of feature attention revealed by frequency tagging in MEG

We used a frequency tagging paradigm to study brain networks mediating feature attention. The stimuli were sequences of compound images of faces and houses flickering at different tagging frequencies. Our fMRI-guided analysis of the MEG/EEG signals revealed a network of areas in frontal and temporal cortex that closely followed the attended stimulus’ frequency at differential phase lags. We further analyzed interactions between the involved brain areas by means of neuronal synchrony and coherence across the spectrum, and we cross-validated the observed functional connectivity with each participant’s individual tractography. Our results imply that the inferior frontal gyrus provides attentional top-down signals to stimulus-tuned temporal areas by engaging into coherent oscillations.