The emergence of the multisensory brain: From the womb to the first steps

Abstract

The becoming of the human being is a multisensory process that starts in the womb. By integrating spontaneous neuronal activity with inputs from the external world, the developing brain learns to make sense of itself through multiple sensory experiences. Over the past ten years, advances in neuroimaging and electrophysiological techniques have allowed the exploration of the neural correlates of multisensory processing in the newborn and infant brain, thus adding an important piece of information to behavioral evidence of early sensitivity to multisensory events. Here, we review recent behavioral and neuroimaging findings to document the origins and early development of multisensory processing, particularly showing that the human brain appears naturally tuned to multisensory events at birth, which requires multisensory experience to fully mature. We conclude the review by highlighting the potential uses and benefits of multisensory interventions in promoting healthy development by discussing emerging studies in preterm infants.

Keywords: Behavioral neuroscience; Developmental neuroscience; Sensory neuroscience.

Graphical abstract

Figure 1

Graphical adaptation of the results of behavioral studies depicting examples of multisensory interactions at birth and early infancy (A) Displays the study by Lewkowicz et al. (2010), showing that multisensory perceptual tuning is broad at birth, enabling them to integrate facial and vocal gestures of non-native social stimuli. (B) Displays the study by Anobile et al. (2021), revealing that multisensory cues help them matching audiovisual stimuli related to numbers. (C) Displays the study of Filippetti et al. (2013), in which newborns showed a preference for infant’s faces while being stroked on their cheek, but only when the image was presented upright. (D) Displays the study of Orioli et al. (2018), showing that newborns can match auditory and visual stimuli that apparently move toward or away from them.

Figure 2

Comparison of three neurophysiological techniques used to assess multisensory interactions in newborns (A) Displays the study by Ronga et al. (2021), in which newborns’ electrophysiological response (EEG) to audio-tactile stimuli was recorded when presented close or far from the body. The authors found an electrophysiological pattern of MSI, with older newborns showing a larger MSI effect. (B) Shows the fNIRS study of Watanabe et al. (2013) aimed at assessing spatiotemporal cortical hemodynamic responses of 3-month-old infants while they perceived visual objects with or without accompanying sounds. The comparison between the two stimulus conditions revealed that the effect of sound manipulation was pervasive throughout the diverse cortical regions, and the effects were specific to each cortical region. Finally, (C) shows the rs-fMRI study by Sours et al. (2017), in which the functional connectivity of two typical multisensory cortical areas was found to be functional at birth: the intraparietal sulcus and the superior temporal sulcus.

Figure 3

The graph depicts a suggestion on how multisensory processing could influence higher-order cognition, in turn impacting how individuals will benefit from it on a behavioral and functional level