Bridging the gap: global disparity processing in the human visual cortex

Cottereau, Benoit R.; McKee, Suzanne P.; Norcia, Anthony M.

doi:10.1152/jn.01051.2011

Cited by 27 publications

(27 citation statements)

References 53 publications

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“…Recent fMRI studies have demonstrated that both areas hMTϩ and V3A are highly responsive to various aspects of MID (Rokers et al 2009). In our previous work, we emphasized that the V3A ROI responded strongly to a central disk alternating between disparities (Cottereau et al 2012b(Cottereau et al , 2012c. Our connectivity analysis extends these results by suggesting that both the hMTϩ and V3A ROIs are con-nected within a cortical network specifically devoted to the processing of MID.…”

Section: Discussionsupporting

confidence: 79%

“…In the MID condition, dots moved out-of-phase between the two eyes and the three bars were perceived as moving in depth between 4 arcmin uncrossed and 4 arcmin crossed. The stimulation frequency was identical to the one used in our previous studies (Cottereau et al 2012b(Cottereau et al , 2012c. At this frequency, our stimuli moved at a speed of 0.28°·s Ϫ1 ·eye Ϫ1 .…”

Section: Methodsmentioning

confidence: 99%

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Dynamics and cortical distribution of neural responses to 2D and 3D motion in human

Cottereau

McKee

Norcia

2014

Journal of Neurophysiology

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The perception of motion-in-depth is important for avoiding collisions and for the control of vergence eye-movements and other motor actions. Previous psychophysical studies have suggested that sensitivity to motion-in-depth has a lower temporal processing limit than the perception of lateral motion. The present study used functional MRI-informed EEG source-imaging to study the spatiotemporal properties of the responses to lateral motion and motion-in-depth in human visual cortex. Lateral motion and motion-in-depth displays comprised stimuli whose only difference was interocular phase: monocular oscillatory motion was either inphase in the two eyes (lateral motion) or in antiphase (motion-indepth). Spectral analysis was used to break the steady-state visually evoked potentials responses down into even and odd harmonic components within five functionally defined regions of interest: V1, V4, lateral occipital complex, V3A, and hMTϩ. We also characterized the responses within two anatomically defined regions: the inferior and superior parietal cortex. Even harmonic components dominated the evoked responses and were a factor of approximately two larger for lateral motion than motion-in-depth. These responses were slower for motion-in-depth and were largely independent of absolute disparity. In each of our regions of interest, responses at odd-harmonics were relatively small, but were larger for motion-in-depth than lateral motion, especially in parietal cortex, and depended on absolute disparity. Taken together, our results suggest a plausible neural basis for reduced psychophysical sensitivity to rapid motion-in-depth. stereomotion; high-density EEG; vision; 3D WHILE TWO-DIMENSIONAL (2D) motion processing has been widely investigated in the primate brain, the neural mechanisms associated with three-dimensional (3D) motion are less well understood. Forty years ago, Beverley (1973a, 1973b) used psychophysical measures to distinguish differences between lateral motion and motion-in-depth (MID). To isolate responses specific to the type of motion, they cleverly used a stimulus that was identical monocularly, a line oscillating continuously back and forth. Either the line moved in the same direction in both eyes, i.e., in phase, producing lateral motion, or in opposite directions between the two eyes, i.e., in antiphase, producing MID. Regan and Beverley's major finding was a difference in the temporal characteristics of the two types of motion; the ability to detect oscillations in depth essentially disappeared above 5 Hz, while oscillations in lateral motion were visible up to about 20 Hz. Later psychophysical studies (Nienborg et al. 2005;Norcia and Tyler 1984) have found that disparity modulation is distinguishable from disparity noise at much higher temporal frequencies than 5 Hz, but the defining characteristics of lateral motion, coherent direction and speed, are not apparent for MID at these high frequencies.Surprisingly, the neural mechanisms responsible for the differences in the dynamics of lateral motion ...

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Section: Discussionsupporting

confidence: 79%

Section: Methodsmentioning

confidence: 99%

Dynamics and cortical distribution of neural responses to 2D and 3D motion in human

Cottereau

McKee

Norcia

2014

Journal of Neurophysiology

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“…EEG artifacts were eliminated off-line using standard procedure whose description can be found in (Cottereau et al 2012c). Before the source imaging procedure (see section 2.8), data were segmented into one-second trials corresponding to one full cycle of the 1Hz disparity display.…”

Section: Methodsmentioning

confidence: 99%

The evolution of a disparity decision in human visual cortex

Cottereau¹,

Ales²,

Norcia³

2014

NeuroImage

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We used fMRI-informed EEG source-imaging in humans to characterize the dynamics of cortical responses during a disparity-discrimination task. After the onset of a disparity-defined target, decision-related activity was found within an extended cortical network that included several occipital regions of interest (ROIs): V4, V3A, hMT+ and the Lateral Occipital Complex (LOC). By using a response-locked analysis, we were able to determine the timing relationships in this network of ROIs relative to the subject's behavioral response. Choice-related activity appeared first in the V4 ROI almost 200 ms before the button press and then subsequently in the V3A ROI. Modeling of the responses in the V4 ROI suggests that this area provides an early contribution to disparity discrimination. Choice-related responses were also found after the button-press in ROIs V4, V3A, LOC and hMT+. Outside the visual cortex, choice-related activity was found in the frontal and temporal pole before the button-press. By combining the spatial resolution of fMRI-informed EEG source imaging with the ability to sort out neural activity occurring before, during and after the behavioral manifestation of the decision, our study is the first to assign distinct functional roles to the extra-striate ROIs involved in perceptual decisions based on disparity, the primary cue for depth.

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“…R. Soc. B 371: 20150257 depth [29,33,34]). The findings most likely explain why the subjects in some previous studies failed to discriminate disparity in aRDSs [21,35].…”

Section: Reversed Depth In Anti-correlated Random-dot Stereogramsmentioning

confidence: 99%

Weighted parallel contributions of binocular correlation and match signals to conscious perception of depth

Fujita

Doi

2016

Phil. Trans. R. Soc. B

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One contribution of 15 to a theme issue 'Vision in our three-dimensional world'. Binocular disparity is detected in the primary visual cortex by a process similar to calculation of local cross-correlation between left and right retinal images. As a consequence, correlation-based neural signals convey information about false disparities as well as the true disparity. The false responses in the initial disparity detectors are eliminated at later stages in order to encode only disparities of the features correctly matched between the two eyes. For a simple stimulus configuration, a feed-forward nonlinear process can transform the correlation signal into the match signal. For human observers, depth judgement is determined by a weighted sum of the correlation and match signals rather than depending solely on the latter. The relative weight changes with spatial and temporal parameters of the stimuli, allowing adaptive recruitment of the two computations under different visual circumstances. A full transformation from correlation-based to match-based representation occurs at the neuronal population level in cortical area V4 and manifests in single-neuron responses of inferior temporal and posterior parietal cortices. Neurons in area V5/MT represent disparity in a manner intermediate between the correlation and match signals. We propose that the correlation and match signals in these areas contribute to depth perception in a weighted, parallel manner.This article is part of the themed issue 'Vision in our three-dimensional world'.

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Bridging the gap: global disparity processing in the human visual cortex

Cited by 27 publications

References 53 publications

Dynamics and cortical distribution of neural responses to 2D and 3D motion in human

Dynamics and cortical distribution of neural responses to 2D and 3D motion in human

The evolution of a disparity decision in human visual cortex

Weighted parallel contributions of binocular correlation and match signals to conscious perception of depth

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