Tuomo Starck1,2, Juuso Nissil3,
Antti Aunio3, Ahmed Abou Elseoud1,2, Jukka Remes1,
Juha Nikkinen1, Markku Timonen4,5, Timo Takala6,
Osmo Tervonen1,2, Vesa Kiviniemi1,2
1Diagnostic Radiology, Oulu
University Hospital, Oulu, Finland; 2Diagnostic Radiology, Oulu
University, Oulu, Finland; 3Valkee Ltd, Finland; 4Department
of Psychiatry, Oulu University, Finland; 5Institute of Health
Sciences, Oulu University, Finland; 6ODL Health ltd, Oulu, Finland
Based on literature about opsin proteins and anecdotal evidence of inherent light-sensitivity of the human brain tissue we tested the hypothesis that brain activity would alter during bright light stimulation via ear canal. ICA dual regression analysis was performed for full band resting state BOLD fMRI data between constant light stimulus (n=24) and sham controls (n=26). Lateral visual IC was significantly different between the groups, light stimulus subjects demonstrated slowly increasing activity around the visual cortex and related regions. Results suggest brain tissue to be inherently light sensitive.