New research reveals that even infants as young as four months old have an innate ability to comprehend how their bodies interact with the world around them. This understanding is evident as they process different sensory information based on the movement of objects they see coming towards them. The study, published in Scientific Reports, highlights early development stages of self-awareness.
For decades, scientists have been fascinated by how humans perceive and interact with the space immediately around them—what is known to researchers as “peripersonal space.” This concept explores how we integrate information from various senses to understand our environment. Previous studies have mainly focused on adults and older children, exploring how sensory predictions—our brain’s way of forecasting sensory events based on past experiences—affect our interaction with our environment.
However, little was known about how and when these abilities develop during infancy. This gap in knowledge led researchers to investigate how infants, from as young as four months old, process multisensory information, particularly how they integrate visual and tactile (touch) information when objects approach them.
The study included two distinct age groups: infants who were four months old and those who were eight months old. These age groups were chosen to capture critical developmental milestones related to sensory processing and motor skills.
The core of the experimental setup involved presenting infants with sequences of visual and tactile stimuli while recording their brain activity using electroencephalography (EEG). The visual stimuli consisted of a 3D-rendered red ball displayed on a screen that either moved towards the infants’ hands or away from them. This movement was designed to simulate objects approaching or receding from the infant in real space.
After a set interval following the visual stimulus, infants received a tactile stimulus, which was a gentle touch on both hands. Importantly, the tactile stimuli were delivered randomly in terms of timing and were not synchronized with the visual stimuli, allowing researchers to specifically measure how prior visual experiences influenced tactile processing.
Electrodes placed on the infants’ scalps recorded the brain’s electrical activity in response to these stimuli. The setup aimed to assess the somatosensory evoked potentials, which are brain responses triggered by tactile stimuli.
When four-month-old infants were presented with tactile stimuli that followed a visual representation of an object approaching them, their brain responses were significantly enhanced compared to when the tactile stimuli followed a visual object receding from them. This suggests that even at such an early stage in development, infants are not only sensitive to visual stimuli relating to objects moving towards or away from them but also link these visual cues to subsequent sensory events — in this case, touch.
“Our findings indicate that even in the first few months of life, before babies have even learned to reach for objects, the multisensory brain is wired up to make links between what babies see and what they feel. This means they can sense the space around them and understand how their bodies interact with that space. This is sometimes referred to as peripersonal space,” said first author Giulia Orioli, a research fellow at the University of Birmingham.
“Of course, humans do this all the time as adults, using our combined senses to perceive where we are in space and making predictions about when we will touch an object or not. But now that we know that babies in the early stages of their development begin to show signs of this, it opens up questions about how much of these abilities are learnt, or innate.”
By eight months, the infants’ responses had evolved, showing developmental changes in how they process these multisensory events. While younger infants in this age group responded similarly to the four-month-olds, the older infants in the eight-month group showed a different pattern of brain activity.
Interestingly, this pattern of enhanced brain responses to approaching visual stimuli did not persist as the infants grew older. Initially, younger 8-month-olds displayed an enhanced response to tactile stimuli preceded by approaching visual motion, similar to 4-month-olds. However, as they got older, their responses were greater for tactile stimuli preceded by receding motion — when objects moved away from them instead of towards them.
This shift suggests that with increasing age, even within the span of a few months, infants not only refine their ability to process sensory information but also begin developing the ability to handle sensory prediction errors — when sensory outcomes differ from what is expected based on the available cues. In this case, the tactile sensation following a visual cue of an object moving away seems to be processed as a “prediction error” by the brain.
“Seeing the older babies show surprise responses suggests that they had not expected the touch due to the visual direction the object was moving in,” said co-author Andrew Bremner, a professor of developmental psychology. “This indicates that as babies proceed through their first year of life, their brains construct a more sophisticated awareness of how their body exists in the space around them.”
While the study provides valuable insights, it has limitations. For instance, the exact nature of the infants’ perception — whether they are truly integrating sensory information in a predictive manner or simply reacting to stimuli — remains unclear. Future research could explore these interactions in different sensory modalities and with other age groups to better understand the developmental trajectory of multisensory integration.
Orioli concluded: “It is a challenge working with newborns, as they spend such a large portion of their time sleeping and eating, but we are starting to have some success working with this age group, and it is going to be fascinating to see if babies only a few days old have the foundations of a sense of their bodies in space. If so, it could be that we are looking at the origins of human consciousness.”
The study, “Visual objects approaching the body modulate subsequent somatosensory processing at 4 months of age,” was authored by Giulia Orioli, Irene Parisi, José L. van Velzen, and Andrew J. Bremner.
