It has been commonly reported that the temporal integration of grating contrast proceeds more slowly as spatial frequency is increased. Such results have based on critical duration for sensitivity to pulses varying in duration, but analyses not assumed full at short durations and neglected effects probability summation over time. To take such into account, we discuss a class analytical models nonlinear integration. On assumption impulse response visual system determines time, develop both...

Perceptual studies make a clear distinction between sensitivity and decision criterion. The former is taken to characterize the processing efficiency of underlying sensory system it increases with stimulus strength. latter regarded as manifestation subjective operation whereby individuals decide on (as opposed react reflexively to) occurrence an event based factors such expectation payoff, in addition its To do so, need have some knowledge internal response distributions evoked by this or...

We describe a family of stimuli consisting colored bars different orientations, which, when presented in rapid succession, may elicit unambiguous motion perception. These permitted the isolation directional spatiotemporal information extracted from oriented luminance clues, nonoriented chromatic-plus-luminance or, were under equiluminant conditions, pure chromatic clues. As general rule, matching orientation induces weaker motion-detection performances than does color. When clues are...

Perceptions of time and space are subject to strong contextual effects. Like their physical counterparts, they appear be bound together. The perceived spatial extent a constant retinal increases with its distance from the observer. duration moving object covered angular trajectory. It follows that objects covering identical trajectories should also increase distance. Using three-dimensionally rendered balls rolling for 600 ms, 900 1,200 ms 5.5°, 11°, 22° in fronto-parallel planes...

The perceived duration of a moving stimulus correlates positively with its speed. It is not known whether such dilation depends on the physical or apparent Here we show latter to be true. shortly presented (500, 900, 1300 ms) Gabor patch whose carrier moved at 1°/s in direction opposite background random black dots rigidly 3°/s appeared last 20% longer and drift 240% faster than same as random-dot background. Assessment speed each two configurations relative absence allowed comparison...

We present a simple reaction time (RT) versus temporal order judgment (TOJ) experiment as test of the perception–action relationship. The improves on previous ones in that it assesses for first RT and TOJ trial-by-trial basis, hence allowing study two behaviors within same task context and, most importantly, association to "correct" "incorrect" TOJs. RTs pairs stimuli are significantly different depending associated TOJs, an indication perceptual motor decisions based internal response....

In 1885, Adolphe-Moïse Bloch asked the following simple question “Is there a law describing relationship between duration of light and its perceived intensity?” Based on series experiments using Foucault regulator candle, concluded that “when lighting varies from 0.00173 to 0.0518 seconds (…) [visible] is markedly in inverse proportion duration”—his famous law. As this pertains more general hotly debated accumulation sensory information over time, it timely offer public full translation...

Abstract In everyday life moving objects often follow irregular or repetitive trajectories for which distinctive events are potentially noticeable. It is known that the perceived duration of distorted, but whether distortion due to temporal frequency speed remains unclear. Disentangling contribution these factors distortions ecologically relevant: if were dependent on speed, it should contract with distance from observer objects. Here, we asked observers estimate an object rotating at...

Motion-induced blindness (MIB) is one of the most enigmatic perceptual disappearance phenomena. Here we suggest that MIB may be caused by combined effects two distinct adaptation processes: shared with other non-MIB configurations and entailing a response-gain reduction, second, MIB-specific transient-to-sustained incremental inhibition causing contrast-gain reduction. Response-gain reduction evidenced brightness-tracking experiment where 1-minute brightness time course an target compared to...

The processes underlying motion-induced blindness (MIB) are widely debated. Ultimately, however, they must reduce to a sensitivity drop and/or an upward shift of the decision criterion. first possibility was tested by assessing detection threshold for contrast (or luminance) increment applied MIB target under its visible and suppressed phases. This performed over whole range reference contrasts (yielding standard Threshold vs. Contrast [TvC] function) with 2AFC staircase procedure. second...

We have developed a computational model for texture perception which has physiological relevance and correlates well with human performance. The attempts to simulate the visual processing characteristics by incorporating mechanisms tuned detect luminance-polarity, orientation, spatial frequency color, are characteristic features of any textural image. obtained very good correlation between model's simulation results data from psychophysical experiments systematically selected set stimuli...

Abstract Previous detection performances obtained in a multi-varied contrast environment showed that observers tend to report significantly less the occurrence of relatively lower targets and more higher ones than conditions where each these stimuli was tested isolation (Gorea & Sagi, 2000). This criterion shift phenomenon is form contrast-dependent extinction normal observers. To add ground analogy between this type "natural" stroke-related one, we present series experiments identical are...

Detection and identification performances for vertical horizontal target elements embedded within an array of oriented noise were measured as a function the orientation difference between elements. obtained with one three clustered together displayed such that they formed schematic face-like pattern significantly better than those same in arbitrary, symmetrical or asymmetrical, configuration. This was so even though face nonface stimuli well below detection threshold their parts. thresholds...

A moving grating oriented +/- 45 degrees to the vertical can be perceived at choice as drifting along a left-right or up-down directional axis. When stimulus is presented alone, direction discrimination thresholds are independent of specified response-axis. However, they strongly depend on it when superimposed horizontal stationary grating. Facilitation always obtained drift intersections two gratings ('blobs') collinear with response-axis (i.e. orientations and coincide), while inhibition...