Peripheral and central handicap and encoding.

A linear model of information processing led to many experiments on learning difficulties in the subnormal and severely subnormal. It assumes learning can result from a break in the chain of information flow at any point but overlooks compensatory mechanisms common to a developing organism. To compensate for the model's difficulties, we compared blind and deaf children with subnormal and subnormal autistic children (i.e. localized with general cognitive incapacities). Absence of a modality led to alternative encoding strategies, but in certain circumstances they also occurred in the centrally handicapped. Reasons for the similarities and differences are discussed.