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

Abstract

There is growing interest concerning the ways in which the human body, both one's own and that of others, is represented in the developing human brain. In two experiments with 7-month-old infants, we employed advances in infant magnetoencephalography (MEG) brain imaging to address novel questions concerning body representations in early development. Experiment 1 evaluated the spatiotemporal organization of infants' brain responses to being touched. A punctate touch to infants' hands and feet produced significant activation in the hand and foot areas of contralateral primary somatosensory cortex as well as in other parietal and frontal areas. Experiment 2 explored infant brain responses to visually perceiving another person's hand or foot being touched. Results showed significant activation in early visual regions and also in regions thought to be involved in multisensory body and self-other processing. Furthermore, observed touch of the hand and foot activated the infant's own primary somatosensory cortex, although less consistently than felt touch. These findings shed light on aspects of early social cognition, including action imitation, which may build, at least in part, on infant neural representations that map equivalences between the bodies of self and other.

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

“…Keysers et al., ). Building on this, a study with 7‐month‐old infants found that neural regions activated when infants were touched on their own hands (or feet) overlapped with the neural regions activated when infants merely observed someone else's hands (or feet) being touched (Meltzoff et al., ). Infants who saw the touch of another person's hands or feet showed activation in their somatosensory cortex not simply their visual cortex.…”

“…Adult MEG studies have been able to differentiate cortical responses to various parts of the mouth including the upper lip, lower lip, and tongue (Disbrow et al., ; Hari et al., ; Nakamura et al., ). Recent advances in MEG hardware and software have established the utility of MEG for brain imaging studies of human infants (Ferjan Ramírez, Ramírez, Clarke, Taulu, & Kuhl, ; Meltzoff et al., ), and such technology may be useful in future investigations of infant neural body representations including of the mouth region.…”

“…This line of work on actions has been extended to examine infants' neural responses to observing another person's body being touched. In an MEG study with 7-month-old infants, Meltzoff et al (2018) showed that watching another person's hand or foot being touched, even in the absence of infants being touched themselves, activated the infant's own somatosensory cortex. Taken together with the infant mu rhythm findings, this work motivates future studies examining the development of neural body representations and their potential role in early social-cognitive development.…”

“…Such vicarious activation has been hypothesized to facilitate social cognition by enabling observers to relate to the bodily experiences of others (e.g. Hari & Kujala, 2009;Keysers et al, 2010;Meltzoff, Ramírez, Saby, Larson, Taulu, & Marshall, 2018).…”

The untenable omission of touch in maternal sensitivity and attachment research

“…There are also novel investigations that focus on the role that touch plays in early experiences. For example, some researchers are focusing on the role of touch on the organization and plasticity of infant body maps (Meltzoff et al, 2018;Saby, Meltzoff, & Marshall, 2015). The examination of mother and infant touch has also been conducted in at-risk populations such as mothers with depressive symptoms (e.g., Beebe et al, 2008;Feldman, Keren, Gross-Rozval, & Tyano, 2004;Herrera, Reissland, & Shepherd, 2004;Mantis, Mercuri, Stack, & Field, 2018), and touch consistently emerges as a critical variable in developmental and clinical research.…”