Spatiotemporal integration in the detection of coherent motion

Abstract

Abstract-We present data on the signal to noise threshold (SNR) for the impression of coherent. smooth motion in stroboscopicall? moving dot patterns (frame repetitionrate 100 Hz) degraded with additive noise (uncorrelated pattern each new frame). (Both patterns were 250 x 255 square arrays in which a pixel tv~ randomly assigned a light or dark value with probability SO%.) it is found that the threshold varies roughly as the inverse square root of the number of available basic dot correlation pairs. subject to certain constraints that can be interpreted as due to the geometry of basic correlator units subserving the detection of motion. This geometry is estimated from the data and compared with values that have been obtained with independent methods. Phenomenologically the results are simple: when the target field is enlarged in the direction perpendicular to the motion the SNR threshold follows the theoretical expectations. Otherwise the variation is stronger. which points to a recruitment of new units. For an impression of movement to occur the smaliest targets are short thin strips elongated in the direction of motion (e.g. 2.

Properties of individual movement detectors as derived from behavioural experiments on the visual system of the fly

“…Miles et al 1986), and for man in various psychophysical studies (e.g. Burr 1981;van Doom and Koenderink 1984). Particularly interesting in the present context is the study of van Doom and Koenderink (1984) which revealed that the detectability of coherent motion is gouvemed by a trade-off between the pattern size and the presentation time.…”

“…Burr 1981;van Doom and Koenderink 1984). Particularly interesting in the present context is the study of van Doom and Koenderink (1984) which revealed that the detectability of coherent motion is gouvemed by a trade-off between the pattern size and the presentation time. It should be emphasized that the terms "spatial" and "temporal integration" are used here only in a colloquial and not in a mathematical sense.…”

Detection of temporal order of noise-like luminance functions

“…In this case, the temporal integration in Figure 4 could be exchanged for a spatial integration over detectors. Indeed van Doom and Koenderink (1983) found evidence of the interchangeability of spatial and temporal integration in motion vision. McKee and Welch (1985) have reported velocity discrimination thresholds for localized stimuli that reach asymptotic levels already at presentation times under 100 msec.…”

Time, change, and motion: The effects of stimulus movement on temporal perception

“…A growing body ofliterature exists on the relation between time and motion, and includes such topics as velocity estimation (e.g., Algom & Cohen-Raz, 1984;Lappin, Bell, Harm, & Kottas, 1975;Tynan & Sekuler, 1982), time-of-arrival estimation (e.g., Cavallo & Laurent, 1988;Peterken, Brown, & Bowman, 1991;Schiff& Oldak, 1990), and motion detection (e.g., van Doorn & Koenderink, 1984;Verri, Girosi, & Torre, 1990). A number ofstudies have been concerned specifically with the perceived duration of moving stimuli.…”