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Laurent Renier
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Research fields


Sensory substitution:

Sensory substitution refers to the use of one sensory modality to supply environmental information normally gathered by another sense. The replacement of a sense by another one is an interisting way to help people with a sensory disability, but it also raises many theorethical questions regarding the nature of the perceptions obtained that way.

Historically, the term "sensory substitution" was introduced at the end of the 60’s to indicate the use of one sensory modality to supply environmental information normally gathered by another sense (Bach-y-Rita et al., 1969). Following the first attempts to create tools to compensate the loss of sight (e.g. the long cane to assist blind persons in their displacements), Bach-y-Rita and his collaborators developed the first sensory substitution device that was specifically dedicated to the scientific investigation of cognitive and brain plasticity in congenitally blind persons (Bach-y-Rita et al., 1969; see also Bach-y-Rita, 2004). Since this pioneer work the increasing interest for sensory substitution has given rise conjointly to the development of various sensory substitution devices and to the realization of numerous studies in the cognitive neuroscience sphere (Bach-y-Rita, 1972; Bach-y-Rita and Kercel, 2003a). Sensory substitution is became now a vast study field and constitutes both a research topic per se and a mean to investigate other domains such as human perception and brain plasticity. Currently, two main categories of devices for sensory substitution of vision coexist: those using touch and those using audition. At the Neural Rehabilitation Engineering laboratory at the UCL , a prosthesis that substitutes audition for vision was developped by Cappelle et al. (1998). The so-called PSVA, allows on line translation of visual patterns into sounds that the subject hears through headphones.

Some interesting links:

The neural rehabilitation engineering laboratory

The SENSUB European project

The VOICE

Sensory substitution, Peter Meijer's web site


Current works on sensory substitution:

The purposes of my works on vision substitution with the PSVA were to promote a cognitive approach in this research field and to highlight the similitude existing between vision and sensory substitution of vision. 

Cognitive processes:

Recent studies have shown that perceptions with a sensory substitution device could be affected by visual illusions (the Ponzo illusion and the Vertical-Horizontal illusion). This was was interpreted as the evidence of the recruitement of visual mechanisms wen using a sensory substitution device. In the same perspective, other studies showed the effect of visual experience on the use of the PSVA when perceiving depth or visual illusions. Current studies aimed to identify the cognitive processes involved in the use of a sensory substitution system.

Brain mechanisms:

Several brain imaging studies showed the recruitement of visual brain areas when using the PSVA to recognize 2D figures (Arno et al., 2001) or a 3D scene (Renier et al., 2005b). Currently, we try to better understand the role of the visual cortex in the use of the PSVA.

Perceptual experience:

We try to objectivate with physiological recordings the effect of the visual system on the use of the PSVA as well as the perceptual experience (feeling) when using the PSVA.

Applied aspects:

We try to evaluate the potentialities of sensory substitution devices as assisting tools for sensory deprived persons.


Current works on the effect of vision on higher cognitive functions:
Studying the effect of visual deprivation provides incomparable insight into the role of vision in the development of higher cognitive functions. Consequently, the cognitive organization in the case of early blindness could be considered as a model of the normal cognitive development without those aspects dependending on vision. In this perspective, we are investigating several cognitive functions such as number processing and calculation, working memory and long term memory in congenitally blind persons.


Current works on brain plasticity:
Sensory deprivation, brain lesions as well as the acquisition of new cognitive abilities (learning) affect the organization of the brain in response to the environmental pressure. We try to better understand how these adaptative mechanisms occurs and to link them to the cognitive functions or architecture. Currently, we try to identify the brain modifications following sensory alterations (e.g. early and late blindness and deafness, tinnitus, etc.) 


Key words: sensory substitution, substitution of vision, visual prosthesis, vision rehabilitation, blindness, brain plasticity, depth perception, visual perception, visual illusions, semantic memory, number processing, calculation, working memory, perceptual learning, visual cortex, Brain imaging, PET, fMRI.