Distinct mechanisms of form-from-motion perception in human extrastriate cortex

Abstract

The exquisite sensitivity of the human visual system to form-from-motion (FfM) cues is well documented. However, identifying the neural correlates of this sensitivity has proven difficult, particularly determining the respective contributions of different motion areas in extrastriate visual cortex. Here we measured visual FfM perception and more elementary visual motion (VM) perception in a group of 32 patients suffering from acute posterior brain damage, and performed MRI-based lesion analysis. Our results suggest that severe FfM perception deficits without an associated deficit of VM perception are due to damage to ventral occipito-temporal cortex (VOT), whereas associated deficits of FfM and VM perception are due to damage either in proximity to area MT+/V5 or an area including lateral occipital complex (LOC) and VOT. These data suggest the existence of at least three functionally and anatomically distinct regions in human visual cortex that process FfM signals.

Dorsal–Ventral Integration in the Recognition of Motion-Defined Unfamiliar Faces

“…is a 47-year-old, right-handed man suffering from dementia affecting primarily visuospatial functions as revealed by extensive neuropsychological testing. He exhibited a severe impairment for direction discrimination from coherent motion and orientation discrimination of twodimensional forms-from-motion (Blanke et al 2007). However, neuropsychological testing did not reveal any object recognition deficits, and so we were interested to know whether he could use three-dimensional SFM cues by a system other than his impaired dorsal stream.…”

The Effect of Luminance Condition on Form, Form-from-Motion and Motion Perception

“…Despite the evidences confirming their segregation, recent findings [8,9,10] attest the relevance of the interaction between the dorsal and the ventral stream using stimuli which enhance both M-and P-pathways, such as form-frommotion and biological motion stimuli. These stimuli require the integration of the motion perception to detect the form of an object.…”

“…These stimuli require the integration of the motion perception to detect the form of an object. Several neuropsychological studies have shown that the perception of form created from moving stimuli (form-from-motion) is mediated by specific neural pathways [8,9,10], involving the connections between the M-and Psystems. It is indeed likely that form-from-motion perception can persist despite impaired perception of static form or motion [for a review see ref .…”

“…11]. Deficit in form-frommotion perception has been demonstrated in subjects having form and motion perception preserved [8,9,10]. Other studies have described subjects having deficits in motion perception but with preserved form and form-from-motion perception [12,13,14] as well as have been documented cases where a deficit in static form perception saw unaltered first order motion and form-from-motion perception [14].…”

“…This results underline that the ability to extract form-frommotion is not derived from simple summation of the information from form and motion but depends on the functioning of larger neural networks. Some authors hypothesized that this complex neural network depends on a connection, described as a 'crosstalk', between the two visual pathways [8,11].…”