Perception and representation in the visual brain and in visual art

The world is a complex reality where everything exists in relation to something else. Each object, animate or inanimate, appears to the observer vested with many qualities or properties. "Every visible body, in so far as it affects the eye, includes three attributes; that is to say: mass, form, and colour" (Leonardo da Vinci, Trattato della Pittura). Objects and their properties are related to each other by conventional or natural relationships that get incorporated by the functional brain through experience. A natural relationship is, for example, the one between an object and its colour, while a conventional one is, for example, the one between an object and its name. What happens when these relationships are violated? A new way of perceiving and representing emerges that exposes the contribution to vision of elaboration and interpretation shaped by previous experience. This thesis explores the changes in visual perception and artistic representation due to this violation, by studying brain activity and by analysing the artistic currents that have stressed the problem of the relationships between objects and colours, or between images and words. The first part analyses the brain processes associated with the perception of objects dressed in natural or un-natural colours and the use of colours by artists like Monet or the Fauvists. The second part addresses the problem of objects' representation. The question addressed is of what neural pathways the brain uses when viewing drawings and words that depict the same or different objects, as in the paintings of Magritte. What we have found is that, in addition to visual cortical areas traditionally associated with the processing of visual features, prefrontal areas are involved in the integrated perception of the various attributes of an object and in the processes that link the content of sensory stimuli to memory