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

Abstract

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 ...

Vergence eye movements in patients with schizophrenia

“…Given that these same cortical regions process not only visual motion signals but also the disparity and motion-in-depth signals that guide vergence tracking (e.g. Likova and Tyler, 2007; Rokers et al, 2009; Cottereau et al, 2011, 2014), our finding that the gain in vergence tracking is reduced in patients with schizophrenia is consistent with these previous findings. Further studies are therefore clearly needed that use psychophysics and fMRI to investigate the processing of both cyclopean and non-cyclopean disparity and motion-in-depth signals in patients with schizophrenia.…”

Dorsal and ventral stream contributions to form-from-motion perception in a patient with form-from motion deficit: a case report

“…Furthermore, the strongest activations measured for successful FfM perception and not observed for absent/failed FfM perception, were located in the parieto-occipital regions, part of the dorsal pathway, possibly corresponding to areas V3A and/or IPS. While parieto-occipital activity in response to FfM processing has not been reported in brain imaging studies (Schoenfeld et al 2003;Wang et al 1999;Gulyas et al 1994), these supplementary visual motion areas were found to be fundamental for 3D motion and more specifically for SfM processing (Vanduffel et al 2002;Orban et al 1999;Paradis et al 2000;Peuskens et al 2004;Gulyas et al 1994;Andersen 1989;Zhuang et al 2008;Brouwer and van Ee 2007;Cottereau et al 2014). Interestingly, overlapping activations for SfM and line drawings have been reported in an area located in the vicinity of the IPS region (Murray et al 2003), which suggests its potential role in processing related to form perception.…”

How to use fMRI functional localizers to improve EEG/MEG source estimation

“…Over the last years, the ROI-based approach described in this review has been used to characterize the dynamics and more recently the functional connectivity (Cottereau et al, 2014a) of the responses within the different visual areas. As an example, figure 4 shows the results obtained in one of our previous EEG studies where we were interested in the cortical mechanisms implied in decision-making (Cottereau et al, 2014b).…”

“…Functional ROI-based comparisons both simplify and increase the accuracy of the pooling of the results between subjects, because a co-registration of the individual anatomies, with its inevitable distortion is not necessary. Over the last several years, this approach has been used to study different properties of the visual system: motion processing (Cottereau et al, 2014a; Ales and Norcia, 2009), chromatic processing (Wang and Wade, 2011; Xiao and Wade, 2010), binocular disparity processing (Cottereau et al, 2011; 2012bc), attention (Kim and Verghese, 2012; Verghese et al, 2012; Palomares et al, 2012; Lauritzen et al, 2010), figure-ground segmentation (Appelbaum et al, 2006; 2008; 2010), perceptual decision-making (Cottereau et al, 2014b; Ales et al, 2013) and contrast normalization (Busse et al, 2009; Tsai et al, 2012). Beyond the scope of the visual system, this approach can easily be applied to other sensory systems where fMRI can be used to reliably map functional areas (see e.g.…”