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...5%-accuracy threshold was significantly lower for upright walkers than for inverted walkers (p < .05, two-tailed), as established via bootstrapping analyses on each participant’s data. EXPERIMENT 2 In Experiment 2, we sought to generalize the finding from Experiment 1 by comparing participants’ accuracy for upright Volume 19—Number 5 471 Ayse Pinar Saygin, Jon Driver, and Virginia R. de Sa versus scrambled walkers. Across a range of methodologies, biological-motion research has used scrambled stimuli extensively as control stimuli (e.g., Grossman & Blake, 2002; Ikeda, Blake, & Watanabe, 2005; Pavlova, Lutzenberger, Sokolov, & Birbaumer, 2004; Saygin, 2007; Saygin, Wilson, Hagler, Bates, & Sereno, 2004). An upright walker was the visual stimulus in half the trials, and the remaining half presented a scrambled walker; the two kinds of stimuli were intermingled randomly. Our new control visual stimuli were created by spatial scrambling, that is, by randomizing the starting positions of the dots while keeping their local motion trajectories intact. The scrambled walkers thus had the same (local) information about temporal frequency as the intact walkers, but the relations among visual dots (and therefore the gestalt) were altered. A ...

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...l regions. A survey of previous studies indicates the right hemisphere pSTS region to be more active than the left pSTS during biological motion perception (Bonda et al., 1996; Grossman et al., 2000; =-=Pavlova, Lutzenberger, Sokolov, & Birbaumer, 2004-=-; Pelphrey et al., 2003). A recent evoked potentials study by Hirai, Fukushima, and Hiraki (2003) demonstrated neural signals selective for biological motion over right, but not left, temporo-parietal...

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...ed to the display – it has been suggested that both form and motion based features are used in recognition [5]. Also, observers can detect the presence of a walker within a fraction of the gait cycle =-=[6]-=-. © 2006 ACADEMY PUBLISHER Gait recognition has been a longstanding research topic in computer vision, both using marker data ([7], [8]) as in PLD and using full-body videos ([9], [10], [11]). In gene...

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...engages a specialized neural network that differs from processing of other moving stimuli (Grossman et al. 2000; Vaina et al. 2001; Grossman and Blake 2002; Pelphrey et al. 2003; Jellema et al. 2004; =-=Pavlova et al. 2004-=-; Peelen et al. 2006; Saygin 2007). Proper functioning of this network depends on intact communication between several areas throughout the brain. Early periventricular lesions that impair brain conne...

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...tal cortices, the amygdala (Adolphs, 2003), and the left lateral cerebellum (Sokolov et al., 2010). The right STS is a cornerstone for processing of meaningful body motion (Grossman and Blake, 2002; =-=Pavlova et al., 2004-=-; Pelphrey et al., 2004). Is the social brain sexspecific? This is an open question. To date, studies of sex effects on the social brain have been limited to investigation of face expressions or body ...

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...ght figures (Grossman & Blake, 2001; Hirai et al., 2011; Jokisch et al., 2005). To date, only one studyshas found a comparable response to upright and inverted walkers over the left occipital cortexs(=-=Pavlova et al., 2004-=-).s49sBy contrast, upright facial motion reduced alpha more than control stimuli at parieto-occipital regions. Asstudy comparing the ERP response to upright and scrambled point-light walkers also repo...

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...plex actions (Casile & Giese, 2005; Giese & Poggio, 2003). This conclusion gains some support from inversion effects in biological motion perception. The spontaneous identification of point-light motion displays as biological motion is impaired when they are shown upside down (Bertenthal & Pinto, 1994; Pavlova & Sokolov, 2000; Shipley, 2003; Troje, 2003), even given prior knowledge about display orientation (Pavlova & Sokolov, 2003). Moreover, neural activation characteristic of upright biological motion displays is attenuated or absent when such displays are inverted (Grossman & Blake, 2001; Pavlova et al., 2004). Inversion of point-light displays also disrupts the ability to distinguish the identity of the actors from their actions (Loula et al., 2005), and sex judgements based on gait tend to be reversed (Barclay et al., 1978). While it is likely that inversion of biological motion disrupts the processing of dynamic cues related to movement within the earth’s gravitational field (Barclay et al., 1978; Bertenthal et al., 1987; Pavlova & Sokolov, 2000; Shipley, 2003), there is also some evidence to suggest that inversion of whole-body movements impairs the processing of configural information (Lu et a...

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...n humans (in the form of point light displays) over parietal cortex and right temporal cortex; whereas viewing inverted point light displays only produced gamma band activity in early visual regions (=-=Pavlova et al., 2004-=-). Some investigators posit a central role for gamma band dysfunction (along with NMDA abnormalities) in schizophrenia; this is discussed in the next section (e.g., Lewis et al., 2005; Woo et al., 201...

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... global shape from point-light motion or global motion pattern information. Even at a single agent level, asymmetric oscillatory activities have also been reported during perception of a PLW stimulus =-=[24]-=-. Pavlova et al have argued that a stronger left-side enhancement in the oscillatory response over the occipital cortices is likely to reflect the early processing of a coherPage 8 of 10 (page number ...