Linear Acceleration Modifies the Perceived Velocity of a Moving Visual Scene

Perception ◽  
1977 ◽  
Vol 6 (5) ◽  
pp. 529-540 ◽  
Author(s):  
Bernard Pavard ◽  
Alain Berthoz
Keyword(s):  
Simple Model ◽  
Spatial Frequency ◽  
Visual Stimulus ◽  
Linear Acceleration ◽  
Vestibular Stimulation ◽  
Visual Scene ◽  
Image Velocity ◽  
Image Movement ◽  
Velocity Perception ◽  
Perceived Velocity

In the present work, we have shown the effect of a vestibular stimulation on the velocity perception of a moving scene. The intensity of this effect is related to the amplitude of the cart acceleration, image velocity, spatial frequency of the visual stimulus, and the angle between the directions of cart and image movement. A simple model has been developed to determine whether the perception of visual movement is due to the geometric projection of the vestibular evaluation on the visual vector, or the inverse.

Velocity Perception in 3-D Environments

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 37-37 ◽  
Author(s):  
H Distler ◽  
H H Bülthoff
Keyword(s):  
Spatial Frequency ◽  
Surface Texture ◽  
Low Frequency ◽  
Picture Plane ◽  
Open Loop ◽  
Driving Simulation ◽  
Low Contrast ◽  
Surface Textures ◽  
Velocity Perception ◽  
Perceived Velocity

Velocity perception has been investigated in many experiments with stimuli moving in the picture plane (2-D). For example, experiments with sine-wave gratings have shown that high-frequency patterns are perceived as moving faster than low-frequency patterns, and that high-contrast patterns are perceived as moving faster than low-contrast patterns. We investigated the influence of contrast and spatial frequency on perceived velocity in an open-loop driving simulation to determine whether contrast and spatial frequency account for differences in perceived velocity in complex 3-D environments. The simulated scene consisted of a textured road flanked by two meadows. We used road surface textures with different contrast and spatial frequency contents. In a 2AFC paradigm participants were simultaneously presented two driving simulation sequences depicting vehicles moving at different velocities on roads with different surface textures. Participants judged which vehicle was moving faster. Using an adaptive staircase procedure we determined the point of subjective equality for roads with different surface textures. The results show that perceived velocity in a driving simulation does depend on contrast and spatial frequency of the surface texture. Perceived velocity can be increased by increasing the contrast or the relative amount of high spatial frequencies in the surface texture. The relevance of these results for the design of driving simulators is discussed.

Vertical linear self-motion perception during visual and inertial motion: More than weighted summation of sensory inputs

2005 ◽  
Vol 15 (4) ◽  
pp. 185-195 ◽  
Author(s):  
W.G. Wright ◽  
P. DiZio ◽  
J.R. Lackner
Keyword(s):  
Motion Perception ◽  
Visual Motion ◽  
Test Chamber ◽  
Vestibular Stimulation ◽  
Visual Scene ◽  
Inertial Motion ◽  
Physical Test ◽  
Head Mounted Display ◽  
Linear Oscillation ◽  
Self Motion

We evaluated visual and vestibular contributions to vertical self motion perception by exposing subjects to various combinations of 0.2 Hz vertical linear oscillation and visual scene motion. The visual stimuli presented via a head-mounted display consisted of video recordings of the test chamber from the perspective of the subject seated in the oscillator. In the dark, subjects accurately reported the amplitude of vertical linear oscillation with only a slight tendency to underestimate it. In the absence of inertial motion, even low amplitude oscillatory visual motion induced the perception of vertical self-oscillation. When visual and vestibular stimulation were combined, self-motion perception persisted in the presence of large visual-vestibular discordances. A dynamic visual input with magnitude discrepancies tended to dominate the resulting apparent self-motion, but vestibular effects were also evident. With visual and vestibular stimulation either spatially or temporally out-of-phase with one another, the input that dominated depended on their amplitudes. High amplitude visual scene motion was almost completely dominant for the levels tested. These findings are inconsistent with self-motion perception being determined by simple weighted summation of visual and vestibular inputs and constitute evidence against sensory conflict models. They indicate that when the presented visual scene is an accurate representation of the physical test environment, it dominates over vestibular inputs in determining apparent spatial position relative to external space.

scholarly journals Two-Dimensional Motion Perception in Flies

1993 ◽  
Vol 5 (6) ◽  
pp. 856-868 ◽  
Author(s):  
A. Borst ◽  
M. Egelhaaf ◽  
H. S. Seung
Keyword(s):  
Simple Model ◽  
Motion Perception ◽  
Visual Stimulus ◽  
Vertical Motion ◽  
Two Dimensional ◽  
Spatial Integration ◽  
Optomotor Response ◽  
Pattern Motion ◽  
Motion Detectors

We study two-dimensional motion perception in flies using a semicircular visual stimulus. Measurements of both the H1-neuron and the optomotor response are consistent with a simple model supposing spatial integration of the outputs of correlation-type motion detectors. In both experiment and model, there is substantial H1 and horizontal (yaw) optomotor response to purely vertical motion of the stimulus. We conclude that the fly's optomotor response to a two-dimensional pattern, depending on its structure, may deviate considerably from the direction of pattern motion.

Galvanic vestibular stimulation counteracts hypergravity-induced plastic alteration of vestibulo-cardiovascular reflex in rats

2009 ◽  
Vol 107 (4) ◽  
pp. 1089-1094 ◽  
Author(s):  
Chikara Abe ◽  
Kunihiko Tanaka ◽  
Chihiro Awazu ◽  
Hironobu Morita
Keyword(s):  
Vestibular System ◽  
Vestibular Nucleus ◽  
Pressor Response ◽  
Linear Acceleration ◽  
Vestibular Stimulation ◽  
Vertical Movement ◽  
Galvanic Vestibular Stimulation ◽  
Medial Vestibular Nucleus ◽  
Vertical Movements ◽  
Cardiovascular Reflex

Recent data from our laboratory demonstrated that, when rats are raised in a hypergravity environment, the sensitivity of the vestibulo-cardiovascular reflex decreases. In a hypergravity environment, static input to the vestibular system is increased; however, because of decreased daily activity, phasic input to the vestibular system may decrease. This decrease may induce use-dependent plasticity of the vestibulo-cardiovascular reflex. Accordingly, we hypothesized that galvanic vestibular stimulation (GVS) may compensate the decrease in phasic input to the vestibular system, thereby preserving the vestibulo-cardiovascular reflex. To examine this hypothesis, we measured horizontal and vertical movements of rats under 1-G or 3-G environments as an index of the phasic input to the vestibular system. We then raised rats in a 3-G environment with or without GVS for 6 days and measured the pressor response to linear acceleration to examine the sensitivity of the vestibulo-cardiovascular reflex. The horizontal and vertical movement of 3-G rats was significantly less than that of 1-G rats. The pressor response to forward acceleration was also significantly lower in 3-G rats (23 ± 1 mmHg in 1-G rats vs. 12 ± 1 mmHg in 3-G rats). The pressor response was preserved in 3-G rats with GVS (20 ± 1 mmHg). GVS stimulated Fos expression in the medial vestibular nucleus. These results suggest that GVS stimulated vestibular primary neurons and prevent hypergravity-induced decrease in sensitivity of the vestibulo-cardiovascular reflex.

The spatial frequency effect on perceived velocity

1976 ◽  
Vol 16 (2) ◽  
pp. 169-IN7 ◽  
Author(s):  
H.C. Diener ◽  
E.R. Wist ◽  
J. Dichgans ◽  
Th. Brandt
Keyword(s):  
Spatial Frequency ◽  
Frequency Effect ◽  
Perceived Velocity

Noisy Template Matching: A Model for Detection and Discrimination

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 263-263 ◽  
Author(s):  
W McIlhagga ◽  
A Pääkkönen
Keyword(s):  
Simple Model ◽  
Spatial Frequency ◽  
Template Matching ◽  
Additive Noise ◽  
Frequency Tuning ◽  
Central Place ◽  
Orientation Tuning ◽  
Decision Variable ◽  
Backward Masking ◽  
Spatial Frequency Tuning

The detection and discrimination of simple patterns occupies a central place in visual psychophysics. A wide variety of phenomena have been observed in this paradigm, such as: Weber's law; masking (simultaneous, forward, and backward); masking by noise; spatial frequency tuning; orientation tuning; and area summation. We suggest that many of these phenomena can be explained by a simple model which we call ‘noisy template matching’. In this model, the encoded stimulus is matched to a memorised template. Both stimulus and template are corrupted by additive noise. The template matching operation yields a decision variable, to which more noise is added. This model is very simple, but it has many interesting consequences. It provides qualitative explanations for many of the phenomena mentioned above, and with additional (but we think reasonable) assumptions about lens blur, contrast nonlinearity (Whittle, 1986 Vision Research26 1677 – 1691), uncertainty (Pelli, 1985 Journal of the Optical Society of America2 1508 – 1532), and suboptimal templates, the model also provides good quantitative accounts of these phenomena.

Short latency ocular-following responses in man

1990 ◽  
Vol 5 (2) ◽  
pp. 107-122 ◽  
Author(s):  
R.S. Gellman ◽  
J.R. Carl ◽  
F.A. Miles
Keyword(s):  
Spatial Frequency ◽  
Human Subjects ◽  
Temporal Frequency ◽  
Sine Wave ◽  
Visual Scene ◽  
Limiting Factor ◽  
Response Latencies ◽  
Stimulus Speed ◽  
Ocular Following ◽  
Stationary Objects

AbstractThe ocular-following responses elicited by brief unexpected movements of the visual scene were studied in human subjects. Response latencies varied with the type of stimulus and decreased systematically with increasing stimulus speed but, unlike those of monkeys, were not solely determined by the temporal frequency generated by sine-wave stimuli. Minimum latencies (70–75 ms) were considerably shorter than those reported for other visually driven eye movements. The magnitude of the responses to sine-wave stimuli changed markedly with stimulus speed and only slightly with spatial frequency over the ranges used. When normalized with respect to spatial frequency, all responses shared the same dependence on temporal frequency (band-pass characteristics with a peak at 16 Hz), indicating that temporal frequency, rather than speed per se, was the limiting factor over the entire range examined. This suggests that the underlying motion detectors respond to the local changes in luminance associated with the motion of the scene. Movements of the scene in the immediate wake of a saccadic eye movement were on average twice as effective as movements 600 ms later: post-saccadic enhancement. Less enhancement was seen in the wake of saccade-like shifts of the scene, which themselves elicited weak ocular following, something not seen in the wake of real saccades. We suggest that there are central mechanisms that, on the one hand, prevent the ocular-following system from tracking the visual disturbances created by saccades but, on the other, promote tracking of any subsequent disturbance and thereby help to suppress post-saccadic drift. Partitioning the visual scene into central and peripheral regions revealed that motion in the periphery can exert a weak modulatory influence on ocular-following responses resulting from motion at the center. We suggest that this may help the moving observer to stabilize his/her eyes on nearby stationary objects.

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