scholarly journals Influence of Visual Motion on Tactile Motion Perception

2006 ◽  
Vol 96 (3) ◽  
pp. 1625-1637 ◽  
Author(s):  
S. J. Bensmaïa ◽  
J. H. Killebrew ◽  
J. C. Craig
Keyword(s):  
Visual Stimulus ◽  
Visual Motion ◽  
Temporal Frequency ◽  
Sensory Level ◽  
Temporal Synchrony ◽  
Tactile Stimuli ◽  
Tactile Interaction ◽  
Visual Distractors ◽  
Speed Discrimination ◽  
Perceived Speed

Subjects were presented with pairs of tactile drifting sinusoids and made speed discrimination judgments. On some trials, a visual drifting sinusoid, which subjects were instructed to ignore, was presented simultaneously with one of the two tactile stimuli. When the visual and tactile gratings drifted in the same direction (i.e., from left to right), the visual distractors were found to increase the perceived speed of the tactile gratings. The effect of the visual distractors was proportional to their temporal frequency but not to their perceived speed. When the visual and tactile gratings drifted in opposite directions, the distracting effect of the visual distractors was either substantially reduced or, in some cases, reversed (i.e., the distractors slowed the perceived speed of the tactile gratings). This result suggests that the observed visual-tactile interaction is dependent on motion and not simply on the oscillations inherent in drifting sinusoids. Finally, we find that disrupting the temporal synchrony between the visual and tactile stimuli eliminates the distracting effect of the visual stimulus. We interpret this latter finding as evidence that the observed visual-tactile interaction operates at the sensory level and does not simply reflect a response bias.

scholarly journals Training-induced plasticity enables visualizing sounds with a visual-to-auditory conversion device

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jacques Pesnot Lerousseau ◽  
Gabriel Arnold ◽  
Malika Auvray
Keyword(s):  
Individual Differences ◽  
Visual Information ◽  
Sensory Modality ◽  
Sensory Substitution ◽  
Visual Images ◽  
Visual Functions ◽  
Tactile Stimuli ◽  
Before And After ◽  
Visual Distractors ◽  
Auditory Processes

AbstractSensory substitution devices aim at restoring visual functions by converting visual information into auditory or tactile stimuli. Although these devices show promise in the range of behavioral abilities they allow, the processes underlying their use remain underspecified. In particular, while an initial debate focused on the visual versus auditory or tactile nature of sensory substitution, since over a decade, the idea that it reflects a mixture of both has emerged. In order to investigate behaviorally the extent to which visual and auditory processes are involved, participants completed a Stroop-like crossmodal interference paradigm before and after being trained with a conversion device which translates visual images into sounds. In addition, participants' auditory abilities and their phenomenologies were measured. Our study revealed that, after training, when asked to identify sounds, processes shared with vision were involved, as participants’ performance in sound identification was influenced by the simultaneously presented visual distractors. In addition, participants’ performance during training and their associated phenomenology depended on their auditory abilities, revealing that processing finds its roots in the input sensory modality. Our results pave the way for improving the design and learning of these devices by taking into account inter-individual differences in auditory and visual perceptual strategies.

Speed Discrimination in Luminance and Colour Stimuli as a Function of Contrast

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 49-49
Author(s):  
S M Wuerger ◽  
A H Morgan
Keyword(s):  
Carrier Frequency ◽  
Standard Stimulus ◽  
Consistent Difference ◽  
Adaptive Procedure ◽  
Gabor Function ◽  
Moving Stimulus ◽  
Measured Speed ◽  
Speed Discrimination ◽  
Luminance Stimulus ◽  
Perceived Speed

We measured speed discrimination for isoluminant red - green and luminance-defined moving stimuli. The horizontal profile of the stimuli was a Gabor function with a carrier frequency of 2 cycles deg−1. The standard stimulus was a luminance stimulus with a fixed speed of 2 deg s−1 and a fixed contrast of 0.1. The comparison stimuli were either luminance stimuli (cone contrasts: 0.05, 0.1, 0.2, 0.4) or chromatic stimuli (cone contrasts: 0.025, 0.05, 0.1). The speed of the comparison stimuli was varied by an adaptive procedure. After each trial the observer indicated which of the 2 intervals contained the slower moving stimulus. The stimuli always moved horizontally and the direction was chosen randomly at each trial. The main findings were: (i) For luminance stimuli, the perceived speed was independent of contrast (ranging from 0.1 to 0.4). For colour stimuli, the perceived speed increased with contrast for two out of four observers. (ii) The sensitivity for speed discrimination was independent of contrast for luminance and for colour stimuli. (iii) There was no consistent difference in speed discrimination sensitivity between colour and luminance stimuli when the stimuli were equated in cone contrast.

Short-Term Memory for Speed

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 156-156
Author(s):  
P Thompson ◽  
R Stone ◽  
E Walton
Keyword(s):  
Spatial Frequency ◽  
Short Term Memory ◽  
Temporal Frequency ◽  
Frequency Discrimination ◽  
Sine Wave ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Speed Discrimination ◽  
Sine Wave Gratings

We have measured the retention of information about stimulus speed in visual short-term memory by measuring speed discrimination in a two-interval forced-choice task. We have also measured such discrimination in conditions where a ‘memory masker’ is presented during the interstimulus interval (ISI) in a fashion analogous to the experiment of Magnussen et al (1991 Vision Research31 1213 – 1219). Magnussen et al found that spatial frequency discrimination was disrupted when the mask had a spatial frequency that differed from the test spatial frequency by an octave or more. We have investigated the speed discrimination of 8 Hz, 1 cycle deg−1 drifting sine-wave gratings with the following drifting masks presented in the ISI: (i) 8 Hz 1 cycle deg−1, same direction as the test; (ii) 8 Hz, 8 cycles deg−1, opposite direction to the test; (iii) 8 Hz, 8 cycles deg−1, same direction as the test; (iv) 24 Hz, 3 cycles deg−1, same direction as the test. These masks were chosen to investigate whether the temporal frequency, the spatial frequency, the speed, or the direction of motion of the mask affected retention. We found that in none of these conditions was the discrimination of the test gratings impaired significantly. This pattern of results is therefore different from that found with spatial frequency discrimination and suggests that, whatever mechanism is responsible for the retention of information about speed, it is different from that responsible for the retention of information about spatial frequency.

Perceived Speed of Moving Cyclopean Corrugations Increases with Increasing Disparity Amplitude

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 195-195
Author(s):  
A M Johns ◽  
B J Rogers ◽  
R A Eagle
Keyword(s):  
Spatial Frequency ◽  
Feature Tracking ◽  
Temporal Frequency ◽  
Reference Stimulus ◽  
Experimental Control ◽  
The Poor ◽  
Random Dot Stereograms ◽  
Matching Performance ◽  
Perceived Speed ◽  
Central Fixation

In order to investigate how cyclopean motion is coded by the visual system, the points of subjective equality (PSEs) were measured for (i) speed, (ii) spatial frequency (SF), and (iii) temporal frequency (TF) as a function of peak-to-trough disparity amplitude for cyclopean corrugations. Two panels (3.0 deg × 7.0 deg) of dynamic random-dot stereograms were located 0.5 deg on either side of a central fixation spot. Each panel contained a horizontally oriented sinusoidal cyclopean corrugation whose SF, TF, and disparity amplitude were under experimental control. On each trial, the cyclopean corrugations were displaced vertically in opposite directions. Subjects judged which panel contained the higher SF, TF, or speed depending on condition. The reference stimulus was a sinusoidal corrugation with SF=0.4 cycles deg−1, TF=0.8 Hz, speed of 2.0 deg s−1, and peak-to-trough disparity amplitude of 8 min arc around fixation. We found that, as the peak-to-trough disparity amplitude of the test stimulus increased from 2 min arc to 32 min arc, the PSE for speed decreased from 2.21 deg s−1 to 1.67 deg s−1, compared to a reference speed of 2.00 deg s−1. However, across the same levels of disparity amplitude, the PSE for SF remained constant and the PSE for TF varied but with no consistent pattern. Thus, perceived speed increases with increased disparity amplitude. As all levels of disparity amplitude were above threshold, cyclopean speed cannot be detected by a purely ‘feature-tracking’ mechanism. These metamers and the poor TF matching performance suggest that cyclopean speed is coded by a sparse number of temporal mechanisms.

scholarly journals Orientation Tuning, But Not Direction Selectivity, Is Invariant to Temporal Frequency in Primary Visual Cortex

2005 ◽  
Vol 94 (2) ◽  
pp. 1336-1345 ◽  
Author(s):  
Bartlett D. Moore ◽  
Henry J. Alitto ◽  
W. Martin Usrey
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Visual Processing ◽  
Cortical Neurons ◽  
Temporal Frequency ◽  
Direction Selectivity ◽  
Orientation Tuning ◽  
Orientation Contrast ◽  
Wide Range

The activity of neurons in primary visual cortex is influenced by the orientation, contrast, and temporal frequency of a visual stimulus. This raises the question of how these stimulus properties interact to shape neuronal responses. While past studies have shown that the bandwidth of orientation tuning is invariant to stimulus contrast, the influence of temporal frequency on orientation-tuning bandwidth is unknown. Here, we investigate the influence of temporal frequency on orientation tuning and direction selectivity in area 17 of ferret visual cortex. For both simple cells and complex cells, measures of orientation-tuning bandwidth (half-width at half-maximum response) are ∼20–25° across a wide range of temporal frequencies. Thus cortical neurons display temporal-frequency invariant orientation tuning. In contrast, direction selectivity is typically reduced, and occasionally reverses, at nonpreferred temporal frequencies. These results show that the mechanisms contributing to the generation of orientation tuning and direction selectivity are differentially affected by the temporal frequency of a visual stimulus and support the notion that stability of orientation tuning is an important aspect of visual processing.

Normal and Adapted Visuooculomotor Reflexes in Goldfish

1997 ◽  
Vol 77 (3) ◽  
pp. 1099-1118 ◽  
Author(s):  
Eric Marsh ◽  
Robert Baker
Keyword(s):  
Visual Stimulus ◽  
Visual Motion ◽  
Visual Stimuli ◽  
Adaptive Plasticity ◽  
Visual Training ◽  
Optokinetic Response ◽  
Stimulus Velocity ◽  
Visuomotor Behavior ◽  
Distributed Circuits ◽  
Eye Velocity

Marsh, Eric and Robert Baker. Normal and adapted visuooculomotor reflexes in goldfish. J. Neurophysiol. 77: 1099–1118. Under normal physiological conditions, whole field visual motion generally occurs in response to either active or passive self-motion. In the laboratory, selective movement of the visual surround produces an optokinetic response (OKR) that acts primarily to support the vestibuloocular reflex (VOR). During visual world motion, however, the OKR can be viewed as operating independently over frequency and amplitude ranges insufficient for vestibular activation. The goal of the present study was to characterize this isolated behavior of the OKR in goldfish as an essential step for studying central neuronal correlates of visual-vestibular interactions and the mechanisms underlying oculomotor adaptation. After presentation of either binocular sinusoidal or step visual stimuli, conjugate eye movements were elicited with an amplitude and phase profile similar to that of other vertebrates. An early and a delayed component were measured with different dynamics that could be altered independently by visual training. The ensuing visuomotor plasticity was robust and exhibited five major characteristics. First, the gain of both early and delayed components of the OKR increased >100%. Second, eye velocity decreased 0.5–2.0 s before the change in direction of stimulus velocity. Third, on lengthening the duration of a constant velocity visual stimulus (e.g., from 8 to 16 s), eye velocity decreased toward 0°/s. This behavior was correlated with the direction and period as opposed to the frequency of the visual stimulus (“period tuning”). Fourth, visual stimulus training increased VOR eye velocity with a ratio of 0.6 to 1 to that measured for the OKR. Fifth, after OKR adaptation, eye velocity consistently oscillated in a conjugate, symmetrical fashion at 2.4 Hz in the light, whereas in the dark, a rhythmical low-amplitude eye velocity occurred at the visual training frequency. We conclude that the frequency and amplitude of visual stimuli for eliciting the goldfish OKR are well suited for complementing the VOR. Unlike most mammals, OKR adaptive modifications significantly alter VOR gain, whereas the effects of VOR training are much less on OKR gain. These observations suggest that both distributed circuits and discrete neuronal populations control visuo- and vestibulomotor performance. Finally, the existence of a rhythmic, “period tuned” visuomotor behavior provides a unique opportunity to examine the neuronal mechanisms of adaptive plasticity.

scholarly journals Integration of visual and tactile information in reproduction of traveled distance

2017 ◽  
Vol 118 (3) ◽  
pp. 1650-1663 ◽  
Author(s):  
Jan Churan ◽  
Johannes Paul ◽  
Steffen Klingenhoefer ◽  
Frank Bremmer
Keyword(s):  
Visual Information ◽  
Tactile Stimulus ◽  
Visual Motion ◽  
Air Flow ◽  
Natural World ◽  
Sources Of Information ◽  
Reproduction Task ◽  
Tactile Information ◽  
Tactile Stimuli ◽  
Self Motion

In the natural world, self-motion always stimulates several different sensory modalities. Here we investigated the interplay between a visual optic flow stimulus simulating self-motion and a tactile stimulus (air flow resulting from self-motion) while human observers were engaged in a distance reproduction task. We found that adding congruent tactile information (i.e., speed of the air flow and speed of visual motion are directly proportional) to the visual information significantly improves the precision of the actively reproduced distances. This improvement, however, was smaller than predicted for an optimal integration of visual and tactile information. In contrast, incongruent tactile information (i.e., speed of the air flow and speed of visual motion are inversely proportional) did not improve subjects’ precision indicating that incongruent tactile information and visual information were not integrated. One possible interpretation of the results is a link to properties of neurons in the ventral intraparietal area that have been shown to have spatially and action-congruent receptive fields for visual and tactile stimuli. NEW & NOTEWORTHY This study shows that tactile and visual information can be integrated to improve the estimates of the parameters of self-motion. This, however, happens only if the two sources of information are congruent—as they are in a natural environment. In contrast, an incongruent tactile stimulus is still used as a source of information about self-motion but it is not integrated with visual information.

Low-Level Motion Illusions

2017 ◽  
Author(s):  
Stuart Anstis
Keyword(s):  
Visual Motion ◽  
Viewing Distance ◽  
Low Level ◽  
Space And Time ◽  
Smooth Movement ◽  
Perceived Speed

Visual motion stimuli can be defined as changes in luminance over space and time. Both kinds of change can alter the perceived speed and direction of motion. This chapter covers crossover motion; reverse phi, in which motion between a positive and a negative appears to go backward; the bicycle spokes illusion; the footsteps effect, in which smooth movement looks jerky if the background is striped; zigzag motion, whose direction appears to change with viewing distance; and the furrow illusion of motion, whose direction appears to change when viewed by the fovea versus the periphery. Other concepts covered include the chopstick illusion and the footsteps illusion.

Adaptation in Macaque MT Reduces Perceived Speed and Improves Speed Discrimination

2006 ◽  
Vol 95 (1) ◽  
pp. 255-270 ◽  
Author(s):  
Bart Krekelberg ◽  
Richard J. A. van Wezel ◽  
Thomas D. Albright
Keyword(s):  
Speed Discrimination ◽  
Perceived Speed
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