Perceptual relevance of kinematic components of facial movements extracted by unsupervised learning

Year:
2012
Type of Publication:
In Collection
Authors:
Giese, Martin A.
Chiovetto, Enrico
Curio, Cristobal
Month:
September
BibTex:
Note:
not reviewed
Abstract:

The idea that complex facial or body movements are composed of simpler components (usually referred to as 'movement primitives'or 'action units') is common in motor control (Chiovetto 2011 Journal of Neurophysiology105(4), 1429-31.) as well as in the study of facial expressions (Ekman and Friesen, 1978). However, such components have rarely been extracted from real facial movement data. Methods: Combining a novel algorithm for anechoic demixing derived from (Omlor and Giese 2011 Journal of Machine Learning Research121111-1148) with a motion retargetting system for 3D facial animation (Curio et al, 2010, MIT Press, 47-65), we estimated spatially and temporally localized components that capture the major part of the variance of dynamic facial expressions. The estimated components were used to generate stimuli for a psychophysical experiment assessing classification rates and emotional expressiveness ratings for stimuli containing combinations of the extracted components. Results: We investigated how the information carried by the different extracted dynamic facial movement components is integrated in facial expression perception. In addition, we tried to apply different cue fusion models to account quantitatively for the obtained experimental results. [Supported by DFG CU 149/1-2, GI 305/1-2, EC FP7-ICT grants TANGO 249858 and AMARSi 248311.]