Lectures and seminars Cognitive Neuroscience Club: "Multisensory integration and sensory interaction during development: from science to technology"

Abstract

An organism’s ability to relate to the external world depends on its ability to process and interpret information from the environment correctly. The senses are our window to the world, allowing us to interact with it. For example, when we are on the street, sight helps us understand where to go or where objects of interest are located, but hearing also helps us understand things, like whether a car is approaching or if there are people around us. These simple operations result from complex processes of sensory information processing. However, even though we have many sensory modalities, we only have one brain to integrate these sensory signals. Multisensory integration is a fundamental process that makes perception more than the sum of its parts, improving reaction time, precision, and response accuracy. The mechanisms that subtend multisensory development are still unclear.

In the past years, we have highlighted the importance of sensory interaction in scaffolding multisensory integration processes. Results from our work show how visual modality is critical in developing audio and tactile integration. Without vision, audio space and body representations are altered, making the integration between audio and touch, in some cases, altered or reduced for blind infants and children with respect to sighted ones. In infancy (age 5-36 months), we observe good audio-tactile integration for simple space localization in sighted individuals and reduced multisensory integration in blind infants. Alterations in blind infants are also evident at the tactile level, considering body representation in space. EEG data in blind infants show different cortical processing than sighted ones for tactile localization when the hands are positioned in canonical or un-canonical positions. In childhood (age 5-14 years), we observed in sighted participants a late development of audio and tactile integration for ventriloquist tasks, the rubber hand illusion, and the temporal binding window. No multisensory integration was evident in blind peers.

These results suggest that sensory interaction is one of the building blocks of multisensory development. The strict connection between sensory interaction and multisensory development offers a model to disentangle the basic principles that subtend our ability to learn to interact in a multisensory environment and give the scientific knowledge to develop science-driven technology to improve the quality of life of sensory-impaired individuals.