# Vision drives the neural construction of a two-stage hierarchy of spatial processing in infancy

## TL;DR

This study shows how vision helps infants learn to map touch sensations to external space, while blind infants rely more on body-based signals.

## Contribution

The paper reveals how visual experience shapes the development of spatial perception by influencing somatosensory processing in infancy.

## Key findings

- Sighted infants show posture-sensitive remapping of touch in later somatosensory stages.
- Blind infants maintain contralateral somatosensory activation across processing stages.
- Auditory responses remain spatially stable regardless of posture in both sighted and blind infants.

## Abstract

Here, we demonstrate the critical role of developmental vision in the origins of a neural processing hierarchy in which somatosensory events are mapped from somatotopic locations onto a body representation with respect to external space. Both sighted and severely visually impaired infants showed prominent contralateral somatosensory activation in uncrossed- and crossed-hands postures in the early feedforward stages of processing (45–65 ms). By 105–120 ms following the somatosensory stimulus, anatomically ipsilateral activation was observed in the crossed-hands posture in sighted infants only, which was directly related to behavioral orienting toward the incorrect hand, reflecting a remapping of touches with reference to the position of the limbs in external space. Severely visually impaired infants exhibited a somatosensory response that was persistent contralateral across early and later processing stages, with the early responses associated with behavior. These findings demonstrate how visual experience in early postnatal development constructs the neural-behavioral basis of embodied spatial perception.

•Vision drives the remapping of touch from body-based to external space in infancy•Blind infants rely on anatomical coding during early somatosensory processing•Sighted infants show posture-sensitive remapping in later somatosensory stages•Auditory responses remain spatially stable across posture in both groups

Vision drives the remapping of touch from body-based to external space in infancy

Blind infants rely on anatomical coding during early somatosensory processing

Sighted infants show posture-sensitive remapping in later somatosensory stages

Auditory responses remain spatially stable across posture in both groups

Neuroscience; Developmental neuroscience; Sensory neuroscience