The development of multisensory body representations in the infant brain

• In Event: 2-198 - The growing body: a multisensory challenge

Integrative Statement

Representing one’s own body and limbs is a fundamentally multisensory process involving cutaneous touch and proprioception. As adults, we integrate information from these direct somatosensory receptors with visual and even auditory cues. Yet the multisensory nature of body representations gives rise to a number of neural computational challenges for the developing infant brain. Not only do the sense channels project to different parts of cortex, but they also convey information about the body and limbs in different neural codes and reference frames. Furthermore, physical and behavioural changes in early life necessitate continuous adaptation of these multisensory bodily correspondences.

Recent investigations of infant brain function have delivered a mixed picture of the development of multisensory body representations. Whereas some studies point to visual-tactile interactions by at least 5 months of age, others indicate that required visual modulations of somatosensory processing develop gradually over the first postnatal year. For instance, Rigato et al. (2017) show that when 4-month-old infants visually observe a hand being stroked this modulates their somatosensory responses evoked by a vibrotactile stimulus to their own hand. However, visual information about 6-month-old infants’ own body posture does not influence somatosensory evoked responses as it does in 10-month-olds’ and adults’ (Rigato et al., 2014).

In order to shed some more light on the development of the brain basis of multisensory story body representations, this paper describes recent unpublished findings from two new lines of investigation, addressing infants’ perception of multisensory aspects of their own bodies.

In the first set of studies we show that infants’ perception of events in which objects either approach the body (loom towards) or recede away from it, we find that auditory information about object approach (looming vs. receding instantiated as increases or decreases in the amplitude of a pure tone) modulates visual evoked potentials in 5-month-old infants (p<.005). Furthermore, data from 13 4-month-olds have been collected addressing whether visual looming or receding will modulate a subsequent vibrotactile evoked potential. Data collection will be completed and reported on in this symposium.

In a second line of investigation addressing tactile visual exogenous cuing effects in 4- and 7-month-old infants we have addressed whether tactile cues will modulate subsequent visual evoked potentials according to whether or not the tactile “cue” was a valid or invalid cue to the location of subsequent visual target. Data from 20 7-month-olds show that reliable cuing effects are apparent in this age group (p<.05). Data from 4-month-olds are being collected currently and will be reported at this symposium.

Overall, the current picture indicates that multisensory interactions underlying body representations in adults are apparent early in the first postnatal year. We think it likely that the functional connections between visual auditory and tactile areas which underpin body representations are available from soon after birth. Experience dependent processes may refine these functional connections as the infant develops increasingly sophisticated patterns of activity (Rigato et al, 2014) in his/her environment.

Authors

• Andrew J Bremner, University of Birmingham
  Presenting Author

• Giulia Orioli, University of Birmingham
  Non-Presenting Author

• Rhiannon Thomas, University College London
  Non-Presenting Author

• Jiale Yang, Tokyo University
  Non-Presenting Author