Fig. 1

Bistable plaid stimulus: two superimposed gratings moving in opposite directions can be perceived as either one plaid moving downward (coherent motion) or as two gratings moving past each other (incoherent motion).

Bistable plaid stimulus: two superimposed gratings moving in opposite directions can be perceived as either one plaid moving downward (coherent motion) or as two gratings moving past each other (incoherent motion).