A theoretical analysis of the role of hyperarousal in the learning and behavior of fragile X males

Fragile X syndrome, the most common form of inherited mental retardation, is associated with a broad spectrum of cognitive and behavioral impairments. Researchers have noted a characteristic behavioral profile consisting of social avoidance, as well as verbal and motor repetitive behaviors, in a subgroup of males with fragile X syndrome. Although these behaviors are evident in their most extreme form in males having both fragile X syndrome and autism, milder variants are evident in nonautistic males as well. Clinical data we have collected suggest that the severity of these agitated behaviors starts increasing during adolescence. These data suggest fragile X males have problems with arousal modulation. It is hypothesized that these arousal problems have an impact on both the acquisition and display of cognitive and adaptive skills. Neurocomputational issues that may be relevant to understanding these cognitive and emotional phenomena are discussed.