Spatial and temporal limits of motion perception across variations in speed, eccentricity, and low vision

Abstract

We evaluated spatial displacement and temporal duration thresholds for discriminating the motion direction of gratings for a broad range of speeds (0.06 degrees/s to 30 degrees/s) in fovea and at +/-30 degrees eccentricity. In general, increased speed yielded lower duration thresholds but higher displacement thresholds. In most conditions, these effects of speed were comparable in fovea and periphery, yielding relatively similar thresholds not correlated with decreased peripheral acuity. The noteworthy exceptions were interactive effects at slow speeds: (1) Displacement thresholds for peripheral motion were affected by acuity limits for speeds below 0.5 degrees/s. (2) Low-vision observers with congenital nystagmus had elevated thresholds for peripheral motion and slow foveal motion but resembled typically sighted observers for foveal motions at speeds above 1 degree/s. (3) Suppressive center-surround interactions were absent below 0.5 degrees/s and their strength increased with speed. Overall, these results indicate qualitatively different sensitivities to slow and fast motions. Thresholds for very slow motion are limited by spatial resolution, while thresholds for fast motion are probably limited by temporal resolution.

Fechner, information, and shape perception

“…These factors influence most aspects of spatial vision-for instance, acuity, peripheral vision, low vision, amblyopia, "tarachopia" (Hess, 1982), and the apparent visual field (Koenderink, van Doorn, & Todd, 2009). Image motions add information about spatial order that partially compensates for neural limitations (Lappin, Tadin, Nyquist, & Corn, 2009). …”

The effect of simultaneous flickering light stimulation on global form and motion perception thresholds

“…It is well known that the minimum temporal threshold for motion perception is influenced by stimulus speed. Lappin and colleagues [28] examined this phenomenon meticulously, and from their results it is clear that at 3 • /s (the stimulus speed used in the present study) the minimum is ∼40-50 ms. Therefore, we consider it unlikely that the continuous application of flashing stimulation could interfere with our results.…”

“…Assuming that the refractoriness caused by a single flash lasts approximately 140 ms [20] and that the period of 12 Hz stimulation is ∼83 ms, the time window not covered by refractoriness is always ∼26 ms, which, in the case of either of the applied stimuli, appears to be too narrow for efficient processing. The minimum temporal threshold for form perception is definitely longer [26], and even if motion is processed more rapidly, thorough and well-documented studies found that the minimum is somewhere near 35 ms [27,28]. It is well known that the minimum temporal threshold for motion perception is influenced by stimulus speed.…”

Perception of Biological Motion in Central and Peripheral Visual Fields

“…McKee and Nakayama (1984) demonstrated similar results and concluded that even in the case of stimulus magnification the threshold value for differential motion detection did not reach the same level in the peripheral visual field as it did in the central visual field. However, there are cases when the opposite can also be observed, e.g., the peripheral visual field is more efficient in detecting movement of stimuli with higher velocities (Finlay, 1982;Lappin et al, 2009). Hence, it seems that there are differences between motion perception in central and peripheral visual fields.…”