I just read chapter 5 of Oliver Sacks' “The man who mistook his wife for a hat”, “Hands”. He describes the case of a 60 year old lady with cerebral palsy, who could not do anything with her hands, and more interestingly, with a profound impairment of manual perception – inability to recognize any object by touch. Yet her tactile senses were intact, and she actually could move her hands – although she did not use them. Sacks reasoned that perhaps she had not developed her manual abilities by exploration as a child would, because she had been looked after so much due to her congenital disease. Then as a therapeutic experiment, he tricked her into grasping things with her hands (e.g. putting food slightly out of reach). In a matter of weeks, she developed complete functional use of her hands (after 60 years!), and even started to make remarkable sculptures. Simultaneously, she also developed normal tactile perception (instant object recognition).

This is quite an interesting case for psychological theories of perception. As the sensorimotor theory of perception predicts, it shows that normal perception requires action. Normal sensory neural structures do not by themselves give rise to perception.