I am looking at an EEG acquisition board, specifically where the electrode leads enter the board just prior to RC filtering (channel RC components in the image) and input into an ADS1299 front-end (two 6-pin SMDs at right).
I see an SMD component (green), perhaps a switch or a buffer, which appears to be connecting the inverting input of one (of the eight) amplifiers with the non-inverting input of the next channel up.
What might this SMD component be? I've tried unsuccessfully looking in SMD databases.