Motion evoked brain potentials parallel the consistency of coherent motion perception in humans

The perception of global coherent motion perception in complex motion patterns containing different direction vectors was investigated. Random dot kinematograms (RDK), plaids and fragmented plaid pattern were presented in which direction vectors of the moving elements were varied. In order to elicit coherent motion perception, all elements were displaced in the same direction (delta0 degrees). In a second condition, fifty percent of the elements were moved diagonally downwards to the left, with the remaining elements moving orthogonally (delta 90 degrees). Simultaneously with psychophysical judgements on the perceived motion direction, visual evoked potentials (VEPs) were recorded at occipital electrode positions. Onset of a global coherent motion was associated with a VEP negativity occurring at about 200 ms. The amplitude of this component was clearly reduced when local ambiguous signals could not be integrated to produce the perception of global coherent motion.