Abstract
Over the past 25 years, visual processing has been discussed in the context of the dual stream hypothesis consisting of a ventral (“what”) and a dorsal (“where”) visual information processing pathway. Patients with brain damage of the ventral pathway typically present with signs of visual agnosia, the inability to identify and discriminate objects by visual exploration, but show normal perception of motion perception. A dissociation between the perception of biological motion and non-biological motion has been suggested: perception of biological motion might be impaired when “non-biological” motion perception is intact and vice versa. The impact of object recognition on the perception of biological motion remains unclear. We thus investigated this question in a patient with severe visual agnosia, who showed normal perception of non-biological motion. The data suggested that the patient's perception of biological motion remained largely intact. However, when tested with objects constructed of coherently moving dots (“Shape-from-Motion”), recognition was severely impaired. The results are discussed in the context of possible mechanisms of biological motion perception.
Highlights
Motion perception is an important requirement for an efficient interaction with our environment
Another example can be found in the perception of biological motion, which has been linked to an activation of the ventral and dorsal pathway: besides motion sensitive areas of the dorsal pathway and form selective areas of the ventral pathway a specialized network has been proposed for the perception of biological motion (Vaina et al, 2001b; Michels et al, 2005; Vangeneugden et al, 2009) that involves the anterior superior temporal sulcus (STSa) and superior temporal gyrus (STG) predominantly of the right hemisphere (Perrett et al, 1985; Posner and Dehaene, 1994; Grossman et al, 2000; Puce and Perrett, 2003)
It has been reported that the perception of biological motion might be impaired while general motion processing and object recognition remain intact (Vaina et al, 1990)
Summary
Motion perception is an important requirement for an efficient interaction with our environment. The combined analysis of motion and form is required for the perception of shapes that are defined by coherently moving dots placed in a background of random moving dots (“Shape-from Motion”), which have been associated with an activation of the ventral and dorsal pathway (e.g., Altmann et al, 2004). “Point-light walkers”—a well established model to investigate the perception of biological motion—consist of dots that are placed at locations on invisible lines connecting the main joints of arms and legs of a moving body (Johansson, 1975; Beintema and Lappe, 2002; Casile and Giese, 2005; Troje et al, 2006)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
