Electrophysiological indicators of gesture perception

• Published in: Experimental brain research 2020-03, Vol.238 (3), p.537-550
• Main Authors: Cabrera, Maria E., Novak, Keisha, Foti, Dan, Voyles, Richard, Wachs, Juan P.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Attention - physiology; Biomedical and Life Sciences; Biomedicine; Brain Waves - physiology; Cortex (motor); EEG; Electrodes; Electroencephalography; Electroencephalography - methods; Electrophysiological Phenomena - physiology; Female; Gestures; Humans; Information processing; Ions; Kinematics; Male; Mirror Neurons - physiology; Motor Cortex - physiology; Neurology; Neurosciences; Oscillations; Psychomotor Performance - physiology; Research Article; Sensorimotor integration; Visual cortex; Visual perception; Visual Perception - physiology; Young Adult
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-020-05724-y

Electroencephalography (EEG) activity in the mu frequency band (8–13 Hz) is suppressed during both gesture performance and observation. However, it is not clear if or how particular characteristics within the kinematic execution of gestures map onto dynamic changes in mu activity. Mapping the time course of gesture kinematics onto that of mu activity could help understand which aspects of gestures capture attention and aid in the classification of communicative intent. In this work, we test whether the timing of inflection points within gesture kinematics predicts the occurrence of oscillatory mu activity during passive gesture observation. The timing for salient features of performed gestures in video stimuli was determined by isolating inflection points in the hands’ motion trajectories. Participants passively viewed the gesture videos while continuous EEG data was collected. We used wavelet analysis to extract mu oscillations at 11 Hz and at central electrodes and occipital electrodes. We used linear regression to test for associations between the timing of inflection points in motion trajectories and mu oscillations that generalized across gesture stimuli. Separately, we also tested whether inflection point occurrences evoked mu/alpha responses that generalized across participants. Across all gestures and inflection points, and pooled across participants, peaks in 11 Hz EEG waveforms were detected 465 and 535 ms after inflection points at occipital and central electrodes, respectively. A regression model showed that inflection points in the motion trajectories strongly predicted subsequent mu oscillations ( R 2 = 0.921 , p