motiononset

Motiononset is a term used in vision science and related disciplines to denote the moment at which a moving stimulus begins to move or when motion perception is initiated. It can refer to the physical onset of motion in a stimulus or to the perceptual onset detected by observers. The concept is central to studies of motion perception, timing, and neural processing.

In psychophysics and experimental neuroscience, motiononset is used to define stimulus onset in experiments involving moving patterns, such as drifting gratings or random dot kinematograms. Researchers measure motiononset latency, the time between the physical stimulus onset and a judged or observed perceptual or motor response. Tasks include detecting motion, discriminating direction, or reporting perceived speed, often combined with reaction time, accuracy measures, or timing tasks.

Neuroscientific investigations examine the neural correlates of motiononset. Visual areas, particularly those specialized for motion processing (such as MT/V5 and related dorsal stream regions), show onset-related activity when motion begins. Electrophysiological methods (EEG/MEG), functional imaging, and single-unit recordings are used to characterize the temporal dynamics and latency of motion-related neural responses following motiononset.

In graphics, animation, and computer vision, motiononset can describe the initial moment when an object transitions from a stationary to a moving state within a sequence. This is relevant for timing, motion blur synthesis, and ensuring perceptual continuity in rendered simulations.

See also: stimulus onset, onset latency, motion perception, MT/V5, direction selectivity.