scholarly journals The time course of hemispheric asymmetries in perceptual selection of spatial frequency information

2011 ◽  
Vol 11 (11) ◽  
pp. 307-307
Author(s):  
E. Piazza ◽  
M. Silver
Keyword(s):  
Spatial Frequency ◽  
Time Course ◽  
Hemispheric Asymmetries ◽  
Frequency Information ◽  
Perceptual Selection ◽  
Selection Of

scholarly journals Persistent Hemispheric Differences in the Perceptual Selection of Spatial Frequencies

2014 ◽  
Vol 26 (9) ◽  
pp. 2021-2027 ◽  
Author(s):  
Elise A. Piazza ◽  
Michael A. Silver
Keyword(s):  
Spatial Frequency ◽  
Left Hemisphere ◽  
Hemispheric Asymmetry ◽  
Time Course ◽  
Right Hemisphere ◽  
High Spatial Frequency ◽  
Hemispheric Differences ◽  
Spatial Frequencies ◽  
The Right ◽  
Perceptual Selection

Previous research has shown that the right hemisphere processes low spatial frequencies more efficiently than the left hemisphere, which preferentially processes high spatial frequencies. These studies have typically measured RTs to single, briefly flashed gratings and/or have directed observers to attend to a particular spatial frequency immediately before making a judgment about a subsequently presented stimulus. Thus, it is unclear whether the hemispheres differ in perceptual selection from multiple spatial frequencies that are simultaneously present in the environment, without bias from selective attention. Moreover, the time course of hemispheric asymmetry in spatial frequency processing is unknown. We addressed both of these questions with binocular rivalry, a measure of perceptual selection from competing alternatives over time. Participants viewed a pair of rivalrous orthogonal gratings with different spatial frequencies, presented either to the left or right of central fixation, and continuously reported which grating they perceived. At the beginning of a trial, the low spatial frequency grating was perceptually selected more often when presented in the left hemifield (right hemisphere) than in the right hemifield (left hemisphere), whereas the high spatial frequency grating showed the opposite pattern of results. This hemispheric asymmetry in perceptual selection persisted for the entire 30-sec stimulus presentation, continuing long after stimulus onset. These results indicate stable differences in the resolution of ambiguity across spatial locations and demonstrate the importance of considering sustained differences in perceptual selection across space when characterizing conscious representations of complex scenes.

Receptive Field Size and Response Latency Are Correlated Within the Cat Visual Thalamus

2005 ◽  
Vol 93 (6) ◽  
pp. 3537-3547 ◽  
Author(s):  
Chong Weng ◽  
Chun-I Yeh ◽  
Carl R. Stoelzel ◽  
Jose-Manuel Alonso
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Response Latency ◽  
Time Course ◽  
Frequency Tuning ◽  
Receptive Fields ◽  
Cortical Cell ◽  
Field Size ◽  
Receptive Field Size ◽  
Spatial Frequency Tuning

Each point in visual space is encoded at the level of the thalamus by a group of neighboring cells with overlapping receptive fields. Here we show that the receptive fields of these cells differ in size and response latency but not at random. We have found that in the cat lateral geniculate nucleus (LGN) the receptive field size and response latency of neighboring neurons are significantly correlated: the larger the receptive field, the faster the response to visual stimuli. This correlation is widespread in LGN. It is found in groups of cells belonging to the same type (e.g., Y cells), and of different types (i.e., X and Y), within a specific layer or across different layers. These results indicate that the inputs from the multiple geniculate afferents that converge onto a cortical cell (approximately 30) are likely to arrive in a sequence determined by the receptive field size of the geniculate afferents. Recent studies have shown that the peak of the spatial frequency tuning of a cortical cell shifts toward higher frequencies as the response progresses in time. Our results are consistent with the idea that these shifts in spatial frequency tuning arise from differences in the response time course of the thalamic inputs.

scholarly journals Long-term adaptation to ocular aberrations alters visual processing of spatial frequency information

2016 ◽  
Vol 16 (12) ◽  
pp. 554
Author(s):  
Antoine Barbot ◽  
Krystel Huxlin ◽  
Duje Tadin ◽  
Geunyoung Yoon
Keyword(s):  
Spatial Frequency ◽  
Visual Processing ◽  
Frequency Information ◽  
Ocular Aberrations

No Sex Differences in Contrast Sensitivity and Reaction Time to Spatial Frequency

2002 ◽  
Vol 94 (3) ◽  
pp. 1053-1055 ◽  
Author(s):  
Jennifer L. Solberg ◽  
James M. Brown
Keyword(s):  
Sex Differences ◽  
Reaction Time ◽  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
Frequency Information ◽  
Frequency Processing

This study investigated the possibility of sex differences in spatial frequency processing by measuring contrast sensitivity and reaction time to spatial frequency in the same 20 men and 20 women. This is the first study to investigate sex differences in reaction time to spatial frequency and the first to study sex differences in contrast sensitivity and reaction time within the same participants. No sex differences were found in either contrast sensitivity or reaction time measures, suggesting that women and men process spatial frequency information similarly.

Exposure-Time and Spatial-Frequency Effects in the Tilt Illusion

Perception ◽  
1979 ◽  
Vol 8 (5) ◽  
pp. 557-564 ◽  
Author(s):  
Brian I O'Toole
Keyword(s):  
Spatial Frequency ◽  
Indirect Effects ◽  
Time Course ◽  
Test Line ◽  
Acute Angle ◽  
Direct Effects ◽  
Time Constants ◽  
Frequency Effects ◽  
Tilt Illusion ◽  
Vertical Test

The exposure durations of a vertical test line and a tilted inducing grating were varied and the tilt illusion thus generated was found to change as a function of this variation. Significant direct effects (acute-angle expansion) and indirect effects (acute-angle contraction) were found to occur at times consistent with Andrews's estimate of the time course of inhibition in the visual system when the inducing grating had a spatial frequency of 10 cycles deg−1. However, a 2 · 71 cycles deg−1 grating gave significant effects at exposure durations of 10 as well as 1000 ms, while in a further experiment a 10 · 91 cycles deg−1 grating gave significant effects at 1000 ms only. These results seem to suggest that orientation interactions thought to be due to inhibition (direct effect) and disinhibition (indirect effect) may occur within both sustained and transient channels with concomitant differences in time constants.

scholarly journals Enhanced extrastriate visual response to bandpass spatial frequency filtered fearful faces: Time course and topographic evoked-potentials mapping

2005 ◽  
Vol 26 (1) ◽  
pp. 65-79 ◽  
Author(s):  
Gilles Pourtois ◽  
Elise S. Dan ◽  
Didier Grandjean ◽  
David Sander ◽  
Patrik Vuilleumier
Keyword(s):  
Spatial Frequency ◽  
Evoked Potentials ◽  
Time Course ◽  
Visual Response ◽  
Fearful Faces
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