André Holley is a neurophysiologist. A professor emeritus at Claude Bernard University, in Lyon, he was formerly the director of its sensorineural physiology laboratory and head of the neuroscience doctoral programme. He is the author of L’Eloge de l’odorat and Le Cerveau gourmand, both published by Editions Odile Jacob.

There are five senses: that goes without saying. Over the past few decades, scientific research has revealed how two of the most marvellous of these senses — sight and hearing — function. We now know that the ‘sensory brain’ does not receive messages exclusively from the outside world: it is constantly tensed to receive ‘inner signals’, sent by the body.
The internal sensitivity that responds to signals emitted by the body has its seat in the insular cortex, an area of the brain that neuroimaging studies have recently shown to be involved in such varied phenomena as thirst, hunger, satiety, taste, disgust, anger, fear, as well as maternal love, romantic love, orgasm and even self-awareness.
What if, contrary to what was previously thought not so long ago, external sensations were not the main source of brain stimulation?

• A new grasp of internal sensibility has improved our understanding of human sense awareness.
• A demonstration of how our internal and external sensibilities collaborate in reacting to pain, taste, empathy, movement, etc.
• An exploration of the role of internal sensibility in the emergence of self-awareness.