The Multisensory Plastic Brain along the Life Span: from Neural Basis to Clinical Applications

In everyday life, many different sensory signals (visual, tactile, auditory, olfactory, vestibular) concurrently hit our senses. Although our first-hand perception seems largely dominated by a single modality, typically vision, without any conscious different sensory signals are simultaneously processed and merged together through mechanisms of multisensory integration. The ability to integrate information from different sensory modalities is a fundamental property of the brain: the binding of information from different senses shapes perception, cognition, learning, and behaviour. In many cases, the survival of an organism may even depend on appropriate responses to multisensory stimuli. The brain is endorsed with specialized neural and cortical mechanisms for the synthesis of information derived from the different senses into coherent, unitary, representations. Given its substantial value for optimal brain development and functioning, the research in this field has seen an expansion in the last years, attracting scientists from different disciplines who have explored how the brain bind together multisensory inputs, and how the product of such multisensory binding shapes the human brain and behaviour.

The aim of this research topic is to resume the state of the art and present up-to-date advancements in this area, focusing on the ‘plastic side’ of multisensory integration. So far, cerebral plasticity linked to multisensory integration has been mainly described with reference to deafferentation: acquired or congenital loss of one sense is known to induce a widespread reorganization of the spared sensory pathways, featured by the recruitment of cortical resources of the deprived modality by intact sensory modalities. Instead, less investigated is the issue of how normal and dysfunctional multisensory integration shapes brain functions across the lifespan. Our Research Topic faces this issue focusing on the impact of multisensory integration on optimal neural and cognitive development, as well as its potential for the recovery from neurological and psychiatric diseases impairing multisensory processing. This important issue needs to be faced by different perspectives.

First, by tracking the emergence and maturation of multisensory abilities in animals and humans, and by uncovering whether and how multisensory experiences affect neural, perceptual and cognitive development. Anatomical and neurophysiological studies in animals revealed different potential sources of multisensory neural computations at both cortical and sub-cortical levels (Stein et al., 2014); however less is known about their stability and flexibility across the lifespan and their interaction with the inherent plasticity of the brain.

Second, there is a growing attention to the investigation of the diseases of the central nervous system that may block or alter multisensory processing. Here, the unsolved issue concerns how the human brain reacts to the loss of multisensory abilities, and the behavioural consequences on perceptual and cognitive functioning. In this context, anatomical and physiological measures, connectivity and network analyses are necessary to reveal the pathophysiology of multisensory-related disorders and their impact on the functional organization of modality-specific and multisensory networks.

In turn, this knowledge will be of critical importance for developing novel therapies to treat multisensory-related disorders. Some promising, proof-of-principle, evidence suggests that multisensory-based approaches may be useful for the treatment of different neurological and neuropsychiatric disorders. Such evidence holds great promise for the neurorehabilitation targeting perceptual and cognitive disorders, as well pain and body-related disorders. On a broader perspective, since multisensory integration likely forms the building blocks for higher-order representations, therapies aimed at targeting multisensory functions may likely to produce widespread benefits and to have effects that cascade on behaviour, psychological well-being and functional recovery (Wallance & Stevenson, 2014).

To provide a novel interdisciplinary framework to address this fascinating and multifaceted research topic, we will welcome and actively seek for submissions encompassing behavioural, neuroanatomical, neurophysiological, computational studies, as well as clinical and neuropsychological evidence in human adults and children in healthy and pathological conditions.

Submission of original studies as well as review and opinion papers on this topic are encouraged.