Randomised single-event visual-visual experiment

A flashing checkerboard was presented for 1.25 seconds with ISIs between single-events drawn at random from a Poisson distribution with mean 8 seconds. ISI's were discarded if less than 4 seconds or greater than 16 seconds. Half of the trials were randomly assigned to a black and white checkerboard condition and the others to a blue and yellow checkerboard condition. The black and white checkerboard response was modelled as one regressor and the colour checkerboard response was modelled as another.