Abstract
Pervasive developmental disorders (PDDs) are defined as neurodevelopmental disorders with impairments in social interaction and communication, as well as restricted repertory of activities and interests. PDDs have various subcategories, but they are all placed on the same spectrum of the disorder. The diagnosis is now applied to less severe forms of PDDs, and especially in these cases, the validity of PDD diagnosis has come to be questioned. In this article, the main focus is on the diagnostic concept of impairment in joint attention. Experimental data suggests that a functional deficit of amygdala-limbic network is involved in the process of joint attention, and the deficit is also strongly related to the severity of PDD symptoms.
