scholarly journals Measuring azimuth and elevation of binocular 3D motion direction

2010 ◽  
Vol 9 (8) ◽  
pp. 637-637 ◽  
Author(s):  
S. Heron ◽  
M. Lages
Keyword(s):  
Motion Direction ◽  
3D Motion

scholarly journals On the Aperture Problem of Binocular 3D Motion Perception

Vision ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 64
Author(s):  
Martin Lages ◽  
Suzanne Heron
Keyword(s):  
Visual System ◽  
Motion Perception ◽  
Three Dimensional ◽  
Circular Aperture ◽  
Local Motion ◽  
Motion Direction ◽  
3D Motion ◽  
Aperture Problem ◽  
Points Of View ◽  
Velocity Constraints

Like many predators, humans have forward-facing eyes that are set a short distance apart so that an extensive region of the visual field is seen from two different points of view. The human visual system can establish a three-dimensional (3D) percept from the projection of images into the left and right eye. How the visual system integrates local motion and binocular depth in order to accomplish 3D motion perception is still under investigation. Here, we propose a geometric-statistical model that combines noisy velocity constraints with a spherical motion prior to solve the aperture problem in 3D. In two psychophysical experiments, it is shown that instantiations of this model can explain how human observers disambiguate 3D line motion direction behind a circular aperture. We discuss the implications of our results for the processing of motion and dynamic depth in the visual system.

scholarly journals 3D motion direction estimation
 – Model predictions and data

2018 ◽  
Vol 18 (10) ◽  
pp. 130
Author(s):  
Kathryn Bonnen ◽  
Thaddeus Czuba ◽  
Jake Whritner ◽  
Austin Kuo ◽  
Alexander Huk ◽  
...  
Keyword(s):  
Estimation Model ◽  
Motion Direction ◽  
3D Motion ◽  
Direction Estimation ◽  
Model Predictions

Local Constraints for the Perception of Binocular 3D Motion

2012 ◽  
pp. 90-120
Author(s):  
Martin Lages ◽  
Suzanne Heron ◽  
Hongfang Wang
Keyword(s):  
Computer Simulations ◽  
Visual Processing ◽  
Three Dimensional ◽  
Perceptual Bias ◽  
Probabilistic Framework ◽  
Local Motion ◽  
Motion Direction ◽  
Local Constraints ◽  
3D Motion ◽  
Perceived Velocity

The authors discuss local constraints for the perception of three-dimensional (3D) binocular motion in a geometric-probabilistic framework. It is shown that Bayesian models of binocular 3D motion can explain perceptual bias under uncertainty and predict perceived velocity under ambiguity. The models exploit biologically plausible constraints of local motion and disparity processing in a binocular viewing geometry. Results from computer simulations and psychophysical experiments support the idea that local constraints of motion and disparity processing are combined late in the visual processing hierarchy to establish perceived 3D motion direction.

Gender differences in the Achilles tendon load during the fencing lunge

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Jonathan Kenneth Sinclair ◽  
Lindsay Bottoms
Keyword(s):  
Gender Differences ◽  
Achilles Tendon ◽  
Motion Capture ◽  
Tendon Injury ◽  
Force Platform ◽  
Motion Capture System ◽  
3D Motion ◽  
Loading Rates ◽  
Tendon Pathology ◽  
3D Motion Capture

AbstractRecent epidemiological analyses in fencing have shown that injuries and pain linked specifically to fencing training/competition were evident in 92.8% of fencers. Specifically the prevalence of Achilles tendon pathology has increased substantially in recent years, and males have been identified as being at greater risk of Achilles tendon injury compared to their female counterparts. This study aimed to examine gender differences in Achilles tendon loading during the fencing lunge.Achilles tendon load was obtained from eight male and eight female club level epee fencers using a 3D motion capture system and force platform information as they completed simulated lunges. Independent t-tests were performed on the data to determine whether differences existed.The results show that males were associated with significantly greater Achilles tendon loading rates in comparison to females.This suggests that male fencers may be at greater risk from Achilles tendon pathology as a function of fencing training/ competition.

scholarly journals Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

2021 ◽  
Author(s):  
Filippo Ghin ◽  
Louise O’Hare ◽  
Andrea Pavan
Keyword(s):  
High Frequency ◽  
Discrimination Task ◽  
Temporal Dynamics ◽  
Random Noise ◽  
Decomposition Analysis ◽  
Oscillatory Activity ◽  
Motion Direction ◽  
Time Frequency ◽  
Direction Discrimination ◽  
Transcranial Random Noise Stimulation

AbstractThere is evidence that high-frequency transcranial random noise stimulation (hf-tRNS) is effective in improving behavioural performance in several visual tasks. However, so far there has been limited research into the spatial and temporal characteristics of hf-tRNS-induced facilitatory effects. In the present study, electroencephalogram (EEG) was used to investigate the spatial and temporal dynamics of cortical activity modulated by offline hf-tRNS on performance on a motion direction discrimination task. We used EEG to measure the amplitude of motion-related VEPs over the parieto-occipital cortex, as well as oscillatory power spectral density (PSD) at rest. A time–frequency decomposition analysis was also performed to investigate the shift in event-related spectral perturbation (ERSP) in response to the motion stimuli between the pre- and post-stimulation period. The results showed that the accuracy of the motion direction discrimination task was not modulated by offline hf-tRNS. Although the motion task was able to elicit motion-dependent VEP components (P1, N2, and P2), none of them showed any significant change between pre- and post-stimulation. We also found a time-dependent increase of the PSD in alpha and beta bands regardless of the stimulation protocol. Finally, time–frequency analysis showed a modulation of ERSP power in the hf-tRNS condition for gamma activity when compared to pre-stimulation periods and Sham stimulation. Overall, these results show that offline hf-tRNS may induce moderate aftereffects in brain oscillatory activity.

Sign in / Sign up

Export Citation Format

Share Document