The rotating Pulfrich effect, and a new method of determining visual latency differences

A rotating Pulfrich effect is described and analysed in relation to the Fertsch-Pulfrich latency difference theory. Although some of the predictions conflicted with observations described by Pulfrich [Naturwissenschaften 10, 553-564 (1922)], they were confirmed by experiment, and led to a simple and sensitive method of determining visual latency differences.