Abstract
While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors.
Highlights
The visual system can reconstruct a perceptual scene from motion cues alone
Neuroimaging studies suggest that biological motion (BM) data is processed within the superior temporal sulcus (STS) [9,10,11,12]
Participants completed a sequence discrimination task during the EEG recordings. This tested their ability to differentiate between facial motion sequences that were presented in a continuous series
Summary
The visual system can reconstruct a perceptual scene from motion cues alone. For example, a human walker can be detected from just a dozen moving dots [1]. Neuroimaging studies suggest that BM data is processed within the superior temporal sulcus (STS) [9,10,11,12] This substrate is a convergence point for dorsal and ventral pathways, and has multimodal associations with the amygdala, fusiform gyrus, MT+/ V5 and cerebellum [10,13,14,15,16]. Sakihara et al, [49] found alpha, theta and beta suppression occurring over occipitotemporal areas during familiar, unfamiliar and own face perception Such activity may illustrate the structural and semantic encoding of facial information [49,50]. These negative images disrupt the N170 face-selective component and early structural encoding [56,57] Together, these measures comprise an effective tool in evaluating facial motion perception [58,59]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
