Functional magnetic resonance imaging has decoded complex information about naturalistic stimuli using brain responses, but other non-invasive technologies have not achieved similar decoding capabilities. To evaluate feasibility of naturalistic visual decoding with diffuse optical tomography (DOT), a 6.5-mm-spaced optode grid was employed to decode which of four naturalistic, 90-second, audio-free movie clips was viewed by human subjects. Over 85% average decoding accuracy was achieved using a simple template-matching decoder, and this exceeded the accuracy from a sparser optode grid with 13-mm spacing. High-density DOT is therefore promising for more-complex neural decoding tasks in the future.
