Recent advances in understanding the effects of flickering light stimulation for entraining gamma waves in the human brain have been extensively studied with various light intensities, colors, and flickering frequencies. In this study, we have conducted an fMRI experiment with 24 young healthy subjects with randomized sequences of rest, 20, and 40 Hz flickering frequency stimulation blocks and performed functional brain connectivity analysis of selected brain networks and atlases. Along with strengthened functional intra-network connectivity over the increasing frequency of stimulation, we also report some key networks and regions that exhibited significant inter-network connectivity at 40 Hz stimulation.