[Face recognition in autism]

We conducted a survey of the literature on face recognition (FR), an activity that is essential for social relations and their dynamics. Unlike the recognition of non facial objects, this type of recognition is a special process since it is based on the detection of individual features. The most characteristic clinical parameter of autistic subjects is their inability to relate socially, possibly due to the difficulty they have in processing faces, although they are more skilled at recognising objects.

We describe the two mechanisms involved in FR, one based on features and the other referring to the whole. The latter can be further divided into overall processing that allows a whole image to be compared with another previously assimilated image, and the processing of the arrangement of a face that is recognised as a whole. These may correspond to two different neuronal pathways. During the first days of life, the newborn baby has a predilection for faces in their feature and overall aspects, and processing of the arrangement is slower. Visual development in autistic children is erratic, similar to the level of a newborn infant, and their lack of interest for human faces is apparent during the first year of life, as they look at everything as if they were objects, that is, by features.

The analysis of the literature enabled us to determine how FR mechanisms develop in the earliest days of the infant s life. It also highlighted the importance of the integrity of the pathway that facilitates stimulation for the recognition of facial arrangement, which is altered in autistic children perhaps from the peripheral area to the cortex. Further work on peripheral pathways and the fundamental cortical connections that are affected in autistic subjects will help us to understand the inefficiency of their facial arrangement recognition system.