Microsecond sensitivity of the human visual system to irregular flicker

Science  09 Nov 1979:
Vol. 206, Issue 4419, pp. 708-710
DOI: 10.1126/science.493977


A flickering light presented to the eye produces a small alternating voltage at the scalp of a subject. This alternating voltage indicates the following response of the brain to the flicker. If every other flash in the flicker is displaced temporally by as little as 30 microseconds, an asymmetry appears in the brain's alternating voltage. The results suggest an underlying mechanism that may enhance visual detection of high-frequency flicker.