Mechanism
Asperger syndrome appears to result from developmental factors that affect many or all functional brain systems, as opposed to localized effects.Although the specific underpinnings of AS or factors that distinguish it from other ASDs are unknown, and no clear pathology common to individuals with AS has emerged, it is still possible that ASs mechanism is separate from other ASDs.Neuroanatomical studies and the associations with teratogens strongly suggest that the mechanism includes alteration of brain development soon after conception. Abnormal fetal development may affect the final structure and connectivity of the brain, resulting in altered neural circuits controlling thought and behavior. Several theories of mechanism are available; none are likely to provide a complete explanation. General-processing theories
One general-processing theory is weak central coherence theory, which hypothesizes that a limited ability to see the big picture underlies the central disturbance in ASD. A related theory—enhanced perceptual functioning—focuses more on the superiority of locally oriented and perceptual operations in autistic individuals. Mirror neuron system (MNS) theory
The mirror neuron system (MNS) theory hypothesizes that alterations to the development of the MNS interfere with imitation and lead to Aspergers core feature of social impairment. One study found that activation is delayed in the core circuit for imitation in individuals with AS.
For example, a person with Asperger syndrome may engage in a one-sided, long-winded speech about a favorite topic, while misunderstanding or not recognizing the listeners feelings or reactions, such as a wish to change the topic of talk or end the interaction. This social awkwardness has been called "active but odd". Such failures to react appropriately to social interaction may appear as disregard for other peoples feelings and may come across as rude or insensitive. However, not all individuals with Asperger syndrome will approach others. Some may even display selective mutism, not speaking at all to most people and excessively to specific others. Some may choose only to talk to people they like.The cognitive ability of children with AS often allows them to articulate social norms in a laboratory context, where they may be able to show a theoretical understanding of other peoples emotions; however, they typically have difficulty acting on this knowledge in fluid, real-life situations. People with AS may analyze and distill their observations of social interaction into rigid behavioral guidelines and apply these rules in awkward ways, such as forced eye contact, resulting in a demeanor that appears rigid or socially naïve. Childhood desire for companionship can become numbed through a history of failed social encounters. Violent or criminal behavior
The hypothesis that individuals with AS are predisposed to violent or criminal behavior has been investigated but is not supported by data.