Imitation and the developing social brain: infants’ somatotopic EEG patterns for acts of self and other

Abstract

A leading question in developmental social-cognitive neuroscience concerns the nature and function of neural links between action perception and production in early human development. Here we document a somatotopic pattern of activity of the sensorimotor EEG mu rhythm in 14-month-old infants. EEG was recorded during interactive trials in which infants activated a novel object using their own hands or feet (“execution” trials) and watched an experimenter use her hands or feet to achieve the same goal (“observation” trials). At central electrodes overlying sensorimotor hand areas (C3/C4), mu rhythm power was reduced (indicating greater cortical activation) during infants' execution of hand acts compared to foot acts. For the central electrode overlying the sensorimotor foot area (Cz), mu power was reduced during the execution of foot versus hand acts. Strikingly similar somatotopic patterns were found in both the action execution and observation conditions. We hypothesize that these somatotopic patterns index an intercorporeal mapping of corresponding body parts between self and other. We further propose that infants' ability to identify self-other equivalences at the level of body parts underlies infant imitation and is an ontogenetic building block for the feelings of intersubjectivity we experience when socially engaged with other people.

Infant brain responses to felt and observed touch of hands and feet: an MEG study

“…The infant mu rhythm exhibited a degree of somatotopy, such that observation of hand actions was associated with greater mu desynchronization at lateral central electrode sites, and observation of foot actions was associated with greater desynchronization at the midline central electrode. A similar somatotopic pattern of mu rhythm desynchronization has been documented during infants’ own production of hand and foot actions (de Klerk, Johnson, & Southgate, ; Marshall, Saby, & Meltzoff, ). These findings are consistent with a much larger infant EEG literature suggesting an involvement of the sensorimotor system in action perception (for reviews, see Cuevas, Cannon, Yoo, & Fox, ; Marshall & Meltzoff, ).…”

Neural representations of the body in 60‐day‐old human infants

“…Cz) when they performed foot actions (de Klerk, Johnson, & Southgate, ; Marshall, Saby, & Meltzoff, ). The mu rhythm was also found to show this response pattern when 14‐month‐old infants simply observed an experimenter performing hand and foot actions (Marshall et al., ; Saby, Meltzoff, & Marshall, ).…”

Development of infant sustained attention and its relation to EEG oscillations: an EEG and cortical source analysis study

“…Infant mu activity is elicited during motion observation and execution (Fox et al, 2016). Marshall and colleagues have consistently found attenuated PSD of infant mu rhythm during infants’ execution and observation of body acts (Marshall, Saby, & Meltzoff, 2013; Marshall et al, 2011; see Marshall & Meltzoff, 2011, for review). The changes in the event-related mu activity has been referred to the “event-related desynchronization” (ERD) in these studies.…”