Dr. Paul Bach-y-Rita, a physician and engineer, introduced the idea of sensory substitution – stimulating one sense, such as touch, to take the place of another, such as sight.
Paul Bach-y-Rita was an American neuroscientist. Bach-y-Rita was one of the first to seriously study the idea of neuroplasticity, and to introduce sensory substitution as a tool to treat patients suffering from neurological disorders.
Paul Bach y Rita Video: “Emerging Concepts of Brain Function”
Paul Bach y Rita Video: “Emerging Concepts of Brain Function”. Interview at the Varela Tribute, Paris, June 2004.
Sensory substitution means to transform the characteristics of one sensory modality into stimuli of another sensory modality. It is hoped that sensory substitution systems can help handicapped people by restoring their ability to perceive a certain defective sensory modality by using sensory information from a functioning sensory modality. A sensory substitution system consists of three parts: a sensor, a coupling system, and a stimulator. The sensor records stimuli and gives them to a coupling system which interprets these signals and transmits them to a stimulator. In case the sensor obtains signals of a kind not originally available to the bearer it is a case of sensory augmentation. Sensory substitution concerns human perception and the plasticity of the human brain; and therefore, allows us to study these aspects of neuroscience more through neuroimaging.
Brain plasticity is the brain’s ability to adapt to the complete absence or the deterioration of a sense. Sensory substitution is therefore most likely explained through the study of brain plasticity. Cortical re-mapping or reorganization takes place when the brain experiences some sort of deterioration. This is an evolutionary mechanism that allows people with the deprivation of a sense to adapt and compensate by using other senses. Functional imaging of congenitally blind patients showed a cross-modal recruitment of the occipital cortex during the realization perceptual tasks such as Braille reading, tactile perception, tactual object recognition, sound localization, and sound discrimination. This shows that blind people can use their occipital lobe, generally used for vision, to perceive objects though the use of other sensory modalities, which would explain their oft-displayed propensity towards increased strength of the other senses.
Bach-y-Rita’s most notable work was in the field of neuroplasticity. He is seen as the first to propose the concept of sensory substitution to treat patients with disabilities, often those caused by neurological problems. One of the first applications of sensory substitution he created was a chair which allowed blind people to ‘see’. The trials he conducted in 1969 are now regarded to be the first form of experimental evidence for neuroplasticity and the feasibility of sensory substitution.
Later in his career, Bach-y-Rita created a device which enabled patients with damaged vestibular nuclei to regain their ability to remain balanced, by using an electrical stimulator placed on the tongue which reacted to a motion sensor affixed to the patient. This application enabled patients to remain balanced without the equipment after several weeks use.