You can. In our experience, we were unable to get reliable performance with SSVEP or m-sequences with targets in the periphery, though - the subject had to be

You can. In our experience, we were unable to get reliable performance with SSVEP or m-sequences with targets in the periphery, though - the subject had to be foveating on the target to get a good response. Given that constraint, an eye tracker would be just as applicable to the patient population, so SSVEP was a bag of disadvantages with no obvious upside.