scholarly journals Contrast and stimulus complexity moderate the relationship between spatial frequency and perceived speed: Implications for MT models of speed perception

2011 ◽  
Vol 11 (14) ◽  
pp. 19-19 ◽  
Author(s):  
K. R. Brooks ◽  
T. Morris ◽  
P. Thompson
Keyword(s):  
Spatial Frequency ◽  
Stimulus Complexity ◽  
Speed Perception ◽  
Perceived Speed ◽  
The Relationship

scholarly journals The Perception of Walking Speed in a Virtual Environment

2005 ◽  
Vol 14 (4) ◽  
pp. 394-406 ◽  
Author(s):  
Tom Banton ◽  
Jeanine Stefanucci ◽  
Frank Durgin ◽  
Adam Fass ◽  
Dennis Proffitt
Keyword(s):  
Virtual Environments ◽  
Optic Flow ◽  
Stride Length ◽  
Walking Speed ◽  
The Gaze ◽  
Head Mounted Display ◽  
Speed Perception ◽  
Perceived Speed ◽  
The Relationship ◽  
Straight Ahead

Studies of locomotion in virtual environments assume that correct geometric principles define the relationship between walking speed and environmental flow. However, we have observed that geometrically correct optic flow appears to be too slow during simulated locomotion on a treadmill. Experiment 1 documents the effect in a head-mounted display. Experiment 2 shows that the effect is eliminated when the gaze is directed downward or to the side, or when the walking speed is slow. Experiment 3 shows that the effect is unchanged by stride length. Experiment 4 verifies that the effect is not attributable to image jitter. The change in perceived speed from straight ahead to side or down gaze coincides with a shift from expanding optic flow to lamellar flow. Therefore, we hypothesize that lamellar flow is necessary for accurate speed perception, and that a limited field of view eliminates this cue during straight-ahead gaze.

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 Effect of Spatial Frequency on Perceived Speed

2004 ◽  
Vol 58 (10) ◽  
pp. 1449-1452
Author(s):  
Haoming Shen ◽  
Yoshifumi Shimodaira ◽  
Gosuke Ohashi
Keyword(s):  
Spatial Frequency ◽  
Perceived Speed

TIME ESTIMATION AS A FUNCTION OF STIMULUS COMPLEXITY AND PERSONALITY

1983 ◽  
Vol 11 (2) ◽  
pp. 77-82 ◽  
Author(s):  
Jacob Lomranz
Keyword(s):  
Information Processing ◽  
Theoretical Model ◽  
Time Estimation ◽  
Complex Nature ◽  
Stimulus Complexity ◽  
Personality Variables ◽  
Complex Stimuli ◽  
Quadratic Relationship ◽  
The Relationship

Following the theoretical model originally proposed by Hogan (1978), this study tests the existence of a “U”-relationship between stimulus complexity and time estimation such that time ‘filled” with simple or complex stimuli is perceived as more extended than when the same time is “filled” with stimuli that is of a moderate complex nature. In addition, the present study assumes that this relationship can be better explained by considering the personality variables of extroversion and introversion and their interaction with stimulus complexity. The results confirmed the existence of a quadratic relationship between stimulus complexity and time(< = 0.001). The relationship between information processing in terms of stimulus complexity, personality variables, and the theme of time estimation is discussed.

Effect of Instructions on a Creative Task: Discipline and Form in Hand Sculptures

1966 ◽  
Vol 22 (3) ◽  
pp. 943-950 ◽  
Author(s):  
Leonard M. Lansky ◽  
John M. Peterson
Keyword(s):  
Three Dimensional ◽  
Stimulus Complexity ◽  
Creative Task ◽  
Wooden Cube ◽  
The Relationship ◽  
New Look

How do different limitations which are imposed on a person affect the quality of his creative product? Different freshman sections in architecture were randomly given different limitations for their first three-dimensional assignment which was to produce a handcarving from a 6-in. wooden cube. The limitations were in the number of edges to be left intact: 0, 3, 6, 9, and 12. As predicted, the products differed in relation to the limitations; however, more specific predictions about which carvings would excel were only partially confirmed because, it is speculated, the staff had focused more on the students' frustrations than on some inherent properties of the task. The data do fit an interpretation which relates the architectural concepts of object, void, and their relationships to the “new look” in motivation wherein focus is on the relationship between stimulus complexity and the person's needs and abilities.

scholarly journals Integration of motion energy from overlapping random background noise increases perceived speed of coherently moving stimuli

2016 ◽  
Vol 116 (6) ◽  
pp. 2765-2776 ◽  
Author(s):  
Jason Chuang ◽  
Emily C. Ausloos ◽  
Courtney A. Schwebach ◽  
Xin Huang
Keyword(s):  
Noise Level ◽  
Background Noise ◽  
Visual Motion ◽  
Random Motion ◽  
Spatial Integration ◽  
Neural Basis ◽  
Motion Energy ◽  
Background Stimulus ◽  
Speed Perception ◽  
Perceived Speed

The perception of visual motion can be profoundly influenced by visual context. To gain insight into how the visual system represents motion speed, we investigated how a background stimulus that did not move in a net direction influenced the perceived speed of a center stimulus. Visual stimuli were two overlapping random-dot patterns. The center stimulus moved coherently in a fixed direction, whereas the background stimulus moved randomly. We found that human subjects perceived the speed of the center stimulus to be significantly faster than its veridical speed when the background contained motion noise. Interestingly, the perceived speed was tuned to the noise level of the background. When the speed of the center stimulus was low, the highest perceived speed was reached when the background had a low level of motion noise. As the center speed increased, the peak perceived speed was reached at a progressively higher background noise level. The effect of speed overestimation required the center stimulus to overlap with the background. Increasing the background size within a certain range enhanced the effect, suggesting spatial integration. The speed overestimation was significantly reduced or abolished when the center stimulus and the background stimulus had different colors, or when they were placed at different depths. When the center- and background-stimuli were perceptually separable, speed overestimation was correlated with perceptual similarity between the center- and background-stimuli. These results suggest that integration of motion energy from random motion noise has a significant impact on speed perception. Our findings put new constraints on models regarding the neural basis of speed perception.

Up-Down Asymmetries in Speed Perception

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 6-6 ◽  
Author(s):  
P Thompson ◽  
L S Stone
Keyword(s):  
Spatial Frequency ◽  
Central Point ◽  
The Other ◽  
Upward Motion ◽  
Optokinetic Response ◽  
Downward Motion ◽  
Preliminary Results ◽  
Sinusoidal Gratings ◽  
Speed Perception

We compared speed matches for pairs of stimuli that moved in opposite directions (upward and downward). Stimuli were elliptical patches (2 deg horizontally by 1 deg vertically) of horizontal sinusoidal gratings of spatial frequency 2 cycles deg−1. Two sequential 380 ms foveal presentations were compared. One of each pair of gratings (the standard) moved at 4 Hz (2 deg s−1), the other (the test) moved at a rate determined by a simple up - down staircase. The point of subjectively equal speed was calculated from the average of the last eight reversals. The task was to fixate a central point and to determine which one of the pair appeared to move faster. Eight of ten observers perceived the upward drifting grating as moving faster than a grating moving downward but otherwise identical. On average (N = 10), when the standard moved downward, it was matched by a test moving upward at 94.7± 1.7(SE)% of the standard speed, and when the standard moved upward it was matched by a test moving downward at 105.1± 2.3(SE)% of the standard speed. On extending this paradigm over a range of spatial (1.5 to 13.5 cycles deg−1) and temporal (1.5 to 13.5 Hz) frequencies, preliminary results (N = 4) suggest that, under the conditions of our experiment, upward motion is seen as faster than downward motion for speeds greater than ∼1 deg s−1, but the effect appears to reverse at speeds below ∼1 deg s−1 with downward motion perceived as faster. Given that an up - down asymmetry has been observed by other investigators for the optokinetic response, both perceptual and oculomotor contributions to this phenomenon deserve exploration.

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