The functional role of the medial motion area V6

Abstract

In macaque, several visual areas are devoted to analyze motion in the visual field, and V6 is one of these areas. In macaque, area V6 occupies the ventral part of the anterior bank of the parieto-occipital sulcus (POs), is retinotopically-organized and contains a point-to-point representation of the retinal surface. V6 is a motion sensitive area that largely represents the peripheral part of the visual field and whose cells are very sensitive to translational motion. Based on the fact that macaque V6 contains many real-motion cells, it has been suggested that V6 is involved in object-motion recognition. Recently, area V6 has been recognized also in the human brain by neuroimaging and electrophysiological methods. Like macaque V6, human V6 is located in the POs, is retinotopically organized, and represents the entire contralateral hemifield up to the far periphery. Human V6, like macaque V6, is a motion area that responds to unidirectional motion. It has a strong preference for coherent motion and a recent combined VEPs/fMRI work has shown that area V6 is even one of the most early stations coding the motion coherence. Human V6 is highly sensitive to flow field and is also able to distinguish between different 3D flow fields being selective to translational egomotion. This suggests that this area processes visual egomotion signals to extract information about the relative distance of objects, likely in order to act on them, or to avoid them. The view that V6 is involved in the estimation of egomotion has been tested also in other recent fMRI studies. Thus, taken together, human and macaque data suggest that V6 is involved in both object and self-motion recognition. Specifically, V6 could be involved in “subtracting out” self-motion signals across the whole visual field and in providing information about moving objects, particularly during self-motion in a complex and dynamically unstable environment.

Retinotopy of emotion: Perception of negatively valenced stimuli presented at different spatial locations as revealed by event‐related potentials

“…Ultimately, this (nonabsolute) dichotomy would explain the differential involvement of dorsal and ventral visual processing systems, traditionally related to vision for action and vision for perception, respectively (Goodale & Milner, ; Milner & Goodale, ), and later confirmed (e.g., Brown, Halpert, & Goodale, ). Indeed, the LoVF is mostly processed by the dorsal visual/viso‐motor system and the UFV by the ventral visual system (Gallivan, Cavina‐Pratesi, & Culham, ; Hadjidimitrakis et al, ; Pitzalis, Fattori, & Galletti, ; Previc, , ; Rossit, McAdam, Mclean, Goodale, & Culham, ). Importantly to our scopes, some clues suggest a processing advantage of emotional stimuli presented at the LoVF, since an enhanced capability of angry faces to capture attention has been detected when presented in this hemifield, this bias reflecting an enhanced LoVF vigilance to protect peripersonal space according to authors (Petrova & Wentura, ).…”

Representation of central and peripheral vision in the primate cerebral cortex: Insights from studies of the marmoset brain

“…Even more pronounced differences can be found in higher-level cortical areas. For example, the dorsal stream area DM (dorsomedial area, also known as V6) exhibits a heavy emphasis on peripheral vision (Colby et al, 1988;Galletti et al, 1999;Pitzalis et al, 2013), whereas the ventral stream area V4 apparently does not contain a representation of the far peripheral visual field at all .…”

The human homologue of macaque area V6A

“…Human V6, like macaque V6, contains a complete retinotopic map of the contralateral hemifield (Pitzalis et al, 2006) and responds to coherent visual motion (Pitzalis et al, 2010, 2012, 2013a,b). So far, there is no conclusive evidence about the existence of a human homologue of macaque area V6A, although an extensive literature has shown activations in the posterior end of dorsomedial PPC, where V6A should be located, during arm reaching and pointing movements (e.g., Filimon et al, 2007, 2009; Cavina-Pratesi et al, 2010; Vesia et al, 2010; Galati et al, 2011).…”