Visual perception and neural correlates of novel ‘biological motion’

Abstract

Studies of biological motion have identified specialized neural machinery for the perception of human actions. Our experiments examine behavioral and neural responses to novel, articulating and non-human 'biological motion'. We find that non-human actions are seen as animate, but do not convey body structure when viewed as point-lights. Non-human animations fail to engage the human STSp, and neural responses in pITG, ITS and FFA/FBA are reduced only for the point-light versions. Our results suggest that STSp is specialized for human motion and ventral temporal regions support general, dynamic shape perception. We also identify a region in ventral temporal cortex 'selective' for non-human animations, which we suggest processes novel, dynamic objects.

Human Functional Magnetic Resonance Imaging Reveals Separation and Integration of Shape and Motion Cues in Biological Motion Processing

“…preference for the intact point-light walker compared with their scrambled versions, in agreement with Pyles et al (2007).…”

“…3A-C). This asymmetry has been previously reported in several other studies investigating fMRI activation for point-light walkers (Grossman et al, 2000;Peuskens et al, 2005;Peelen et al, 2006;Pyles et al, 2007). Therefore, our subsequent analysis focused on the right hemisphere.…”

“…Outlines of areas V1, V2, and V3 are based on a cytoarchitectonic study by Amunts et al (2000) and functional imaging work by Press et al (2001). The colored symbols (see inset) indicate the stereotaxic position of the local maxima and their respective labels, as reported in the following studies: Grossman et al (2000), Grèzes et al (2001), Vaina et al (2001), Grossman and Blake (2002), Beauchamp et al (2003), Santi et al (2003), Grossman et al (2004), Saygin et al (2004), Michels et al (2005), Peuskens et al (2005), Peelen et al (2006), and Pyles et al (2007). Colored voxels exceed the p Ͻ 0.001 uncorrected threshold (fixed-effects analysis) for the subtraction full compared with scrambled biological motion in experiment 2, in which subjects performed a one-back task on biological motion displays portraying complex actions.…”

Ventral aspect of the visual form pathway is not critical for the perception of biological motion

“…Importantly, the two areas that are wellknown to be sensitive and critical to human motion, the pSTS and vPMC (11,13,16,28,30,32,45,49), are spared in all cases.…”

“…To do so, for each patient we carefully delineated the lesion, assessed the magnitude of the damage, and situated the lesion relative to regions in the ventral, lateral, and middle temporal cortex that are standardly associated with biological motion processing, including body parts and visual motion-sensitive regions (e.g., refs. 13,14,20,[31][32][33].…”