Texture Preference and Global Frequency Magnitudes

2003 ◽  
Vol 30 (2) ◽  
pp. 297-318 ◽  
Author(s):  
Gretchen Schira
Keyword(s):  
Spatial Frequency ◽  
Physical Properties ◽  
Visual Stimuli ◽  
Gabor Filters ◽  
Visual Texture ◽  
Aesthetic Preference

A relationship between human preferences for physical properties of visual texture is established in this paper. The author asks whether there is a measurable correlation between aesthetic ratings for textural images and their physical properties. A bank of Gabor filters covering a range of frequencies and orientations are used to extract properties. Three studies are conducted and the correlations between aesthetic ratings and the properties were significant and large. The correlations proved robust when image identifiability was incorporated in the first and third studies and removed from the second study. In this, it is suggested that memory and association are not exclusively driving (aesthetic) preference; that it is also tuned to properties of spatial frequency and orientation of certain visual stimuli.

Visual Stimuli for Strabismic Suppression

Perception ◽  
1977 ◽  
Vol 6 (5) ◽  
pp. 583-593 ◽  
Author(s):  
Clifton M Schor
Keyword(s):  
Spatial Frequency ◽  
Binocular Vision ◽  
Binocular Rivalry ◽  
Visual Stimuli ◽  
Normal Group ◽  
Sensory Fusion ◽  
Sinusoidal Gratings

The effects of orientation and spatial frequency of grating stimuli upon suppression were examined with a binocular rivalry paradigm in a group of ten strabismic patients and in a control normal group. Duration, frequency, and period of rivalry were examined as functions of differences in orientation and spatial frequency of dichoptic achromatic sinusoidal gratings. Records were made of responses by the sighting and by the nonsighting eye as well as responses during periods of combined binocular vision. Strabismic subjects reported normal binocular rivalry when presented with gratings of dissimilar orientation. Suppression of the deviating eye in strabismic subjects occurred with stimuli of similar orientation and was unaffected by spatial-frequency differences between dichoptic stimuli. Suppression was most intense under conditions that normally stimulate stereopsis and sensory fusion.

scholarly journals Encoding of motion by spatial and temporal frequency in the human middle temporal cortex measured by 7T fMRI

2021 ◽  
Author(s):  
Anna Gaglianese ◽  
Alessio Fracasso ◽  
Francisco G. Fernandes ◽  
Ben Harvey ◽  
Serge O. Dumoulin ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Temporal Frequency ◽  
Visual Stimuli ◽  
Temporal Cortex ◽  
Moving Object ◽  
Direct Perception ◽  
List Type ◽  
Primary Role ◽  
Middle Temporal ◽  
Frequency Components

AbstractPerception of environmental dynamic scenes results from the evaluation of visual features such as the fundamental spatial and temporal frequencies components of a moving object. The ratio between these two components represents its speed of motion. The human middle temporal cortex hMT+ has a crucial biological role in the direct encoding of object speed. However, the link between hMT+ speed encoding and the spatiotemporal frequency components of a moving object may be more complex than we thought. Both animal studies and recent human electrocorticography data showed that recorded neuronal populations within MT+/V5 change their speed preferences in accordance with the stimulus fundamental spatial frequency. We disentangle whether such mechanism holds for the entire human MT+. We recorded high resolution 7T blood oxygen level-dependent BOLD responses to different visual motion stimuli as a function of their fundamental spatial and temporal frequency components. We fitted each hMT+ BOLD response with a 2D Gaussian model allowing for distinct and independent selectivity for spatial and temporal frequencies of the visual stimuli or tuning for the speed of motion. We show that: 1) hMT+ encodes the speed of motion via independent tuning of the fundamental spatial frequency component of the visual stimuli, 2) the optimal spatial frequency selectivity of hMT+ is tuned for the low spatial frequency of the visual stimuli and is highly reproducible within subjects. Our results show that hMT+ speed preference changes according to the fundamental spatial frequency presented, demonstrating a primary role of the entire hMT+ in the evaluation of the spatial features of the moving visual input. These findings confirm a more complex mechanism involved in the direct perception of speed than initially thought.HighlightshMT+ speed preference changes in accordance with the fundamental spatial frequencyA small subregion within the complex encodes speed directlyA reproducible selectivity for the low spatial frequency of the stimuli was found

A Dissociation between Reaction Time to Sinusoidal Gratings and Temporal-Order Judgment

Perception ◽  
1994 ◽  
Vol 23 (3) ◽  
pp. 335-347 ◽  
Author(s):  
Thomas Tappe ◽  
Michael Niepel ◽  
Odmar Neumann
Keyword(s):  
Reaction Time ◽  
Spatial Frequency ◽  
Comparison Stimulus ◽  
Motor System ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Visual Stimuli ◽  
Visual Latency ◽  
Sinusoidal Gratings ◽  
Sharp Edges

The effect of the spatial frequency (SF) of visual gratings on reaction time (RT) and temporal-order judgment (TOJ) was examined in three experiments. In experiment 1 the visual stimuli were vertical sinusoidal gratings with SFs between 2 and 8 cycles deg−1 and the comparison stimulus in the TOJ task was a 2300 Hz tone. Whereas SF had a highly significant effect on RT, it left TOJ completely unaffected. To test whether this dissociation was due to the sharp (high SF) horizontal edges of the gratings, a second experiment was carried out with circular stimuli with no sharp edges. These stimuli did produce an effect of SF on TOJ, but it was significantly smaller than was the effect on RT. In experiment 3 we confirmed that this difference was not due to differences in grating orientation between the first two experiments. These findings (a) solve discrepancies between findings reported in the literature and (b) strongly suggest that RT and TOJ cannot be regarded as converging operations for determining ‘visual latency’. This dissociation can best be accounted for by assuming that the output of early stimulus analysis can feed directly into the motor system (direct parameter specification), whereas the conscious representation that is used for TOJ is based on later integrative processes.

Spatial frequency modulates visual cortical response to temporal frequency variation of visual stimuli: an fMRI study

2007 ◽  
Vol 28 (5) ◽  
pp. 547-554 ◽  
Author(s):  
A Mirzajani ◽  
Nader Riyahi-Alam ◽  
Mohammad Ali Oghabian ◽  
H Saberi ◽  
K Firouznia
Keyword(s):  
Spatial Frequency ◽  
Temporal Frequency ◽  
Visual Stimuli ◽  
Cortical Response ◽  
Frequency Variation ◽  
Fmri Study ◽  
Visual Cortical
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