Exploring Body Representations: Effects of Visuotactile Congruency on Sensorimotor EEG Measures

Abstract

There has been a recent growth of interest in exploring the complexities of multisensory processes underlying human body representation. One cross-modal aspect of body representations involves the visuotactile body mapping between tactile stimulation of a body limb and the observation of a body limb. Previous findings demonstrate that visual information influences the spatial and temporal patterning of brain responses to tactile stimulation. By manipulating the congruency of the visuotactile stimuli, the integration of visual and tactile information of the body can be investigated further. In the current studies, electroencephalography (EEG) was used to record the neural responses to touch during congruent and incongruent visuotactile stimuli in adults and infants. Two studies investigated different characteristics of visuotactile congruency on the neural response to touch during observations of others’ bodies. In Study 1, spatial congruency of visuotactile events in adults was examined by recording electrophysiological responses to tactile stimulation of the hand in different postural positions while viewing pictures of hands. In Study 2, visuotactile body mappings were explored within typically developing, preverbal infants. In the second study, infants received tactile stimulation to their hand or foot while viewing the hand or foot of another person. The findings of both studies indicate neural modulations were driven by the viewed stimuli regardless of the visuotactile congruency suggestive of attentional factors at work during late stages of somatosensory processing.