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Neural model of biological motion recognition based on shading cues
BMC Neuroscience volume 16, Article number: P81 (2015)
Point-light or stick-figure biological motion stimuli, due to the absence of depth cues, can induce bistable perception, where the walker is perceived as heading in two alternating directions [1, 2]. Psychophysical studies suggested an importance of depth cues for biological motion perception . However, neural models of biological motion perception so far have focused on the processing of features that characterize the 2D structure and motion of the human body [4, 5]. We extend such models for the processing of shading cues in order to analyze the three-dimensional structure of walkers from monocular stimuli.
As extension of a learning-based neural model , we add a 'shading pathway' that computes the internal contrast gradients that vary with the 3D view of the walker, even if the silhouette information remains identical (Figure 1A-C). The model exploits physiologically plausible operations. After suppression of strong external luminance gradients caused by the boundaries of the silhouette, internal luminance gradient features are extracted by a hierarchy of neural detectors. These gradient features, combined with the shape features extracted by the form pathway of the model in , are used as input for 'snapshot neurons', RBF units that detect 3D body shapes (Figure 1D). These model neurons are embedded within a two-dimensional recurrent neural field  that jointly represents the sequential temporal structure of the stimulus and the view of the walker.
The neural field dynamics reproduces perceptual multi-stability and spontaneous perceptual switching between stimulus views, observed for silhouette stimuli in psychophysical experiments [1, 2]. It also reproduces the disambiguation by addition of shading information and a new perceptual illusion, which illustrates a lighting-from-above prior in the processing of biological motion stimuli.
Vanrie J, Dekeyser M, Verfaillie K: Bistability and biasing effects in the perception of ambiguous point-light walkers. Perception. 2004, 33: 547-560.
Vangeneugden J, De Mazière P, Van Hulle M, Jaeggli T, Van Gool L, Vogels R: Distinct mechanisms for coding of visual actions in macaque temporal cortex. J Neurosci. 2011, 31 (2): 385-401.
Vanrie J, Verfaillie K: Perceiving depth in point-light actions. Perc Psychophys. 2006, 68 (4): 601-612.
Giese MA, Poggio T: Neural mechanisms for the recognition of biological movements and action. Nat Rev Neurosci. 2003, 4: 179-192.
Lange J, Lappe M: A model of biological motion perception from configural form cues. J Neurosci. 2006, 26: 2894-2906.
Amari S: Dynamics of pattern formation in lateral inhibition type neural fields. Biol Cyb. 1977, 27: 77-87.
Supported by EC FP7 ABC PITN-GA-011-290011, HBP FP7-604102, Koroibot FP7-611909, COGIMON H2020-644727, DFG GI 305/4-1, DFG GZ: KA 1258/15-1, and BMBF, FKZ: 01GQ1002A.
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Fedorov, L.A., Giese, M.A. Neural model of biological motion recognition based on shading cues. BMC Neurosci 16 (Suppl 1), P81 (2015). https://doi.org/10.1186/1471-2202-16-S1-P81
- Neural Model
- Biological Motion
- Neural Field
- Motion Recognition
- Gradient Feature