Imagery and blindness

When we speak of mental images we refer to representation of objects in our mind and typically to representation experiences in a visuo spatial form. Think of your last holiday or a beautiful scenario, for example a sunset on the beach, with white sand and green palm trees bending towards the water: is the image vividly present in your mind? Can you see the palms, the sea, the sun? Even if your image can include the memory of other sensory experiences, the sound of the waves, the salty smell of the sea and the feel of the fresh air on your skin, the most salient aspects of your image are surely associated with what you saw. By definition, this central portion of the image is visual and seems to be based on the visual experience, which is not, however, available to the congenitally blind. Thus an apparently logical consequence would be that blind people cannot have mental images. However, this is in fact a myth since a modern concept of mental imagery is less strict in placing the visual experience as the necessary condition for the ability to generate mental images. This latter idea is also based on the observation that blind people themselves report having mental images and on the widely spread assumption the humans tend to compensate for their deficits. The latter assumption has generated an opposite paradoxical myth whereby blind people may have mental images as clear as, as efficient as or even better than sighted people.