The 4 main defenitions of a person with Asperger can be:
-Social activities are to wearing to bear
-Special interests
-Different language handling
-Problems with fast changes

But this does not mean AS is a drawback as if it is one of his/hers special interest they tend to have extrodinary ability to concentrate, focus, sharpen mind and enormous endurance.
AS is a Nerological discrepancy wicch means that the brain from a person with AS works in a different manner then that of a "normal" person.
Also AS is the only Nerological condition wich is SOLY biological (Although its still in the genes as well), the others are a combination of biological and psycological.

“Asperger's disorder or syndrome is characterized by impaired social interaction, normal intelligence, and adequate language skills in the areas of grammar and vocabulary. The symptoms are pervasive in nature and usually manifested in childhood. Despite the gravity and chronicity of the condition, the medical literature remains sparse and offers no information about possible neuropathologic underpinnings. The present study is a case report on two patients with Asperger's syndrome. Neuropathologic examination revealed no degenerative changes or gliosis. A more detailed assessment with computerized image analysis indicated abnormalities in the minicolumnar organization of the three areas examined (9, 21, 22) (P = .032). Specifically, minicolumns were smaller, and their component cells were more dispersed than normal. A similar neuropathology has recently been reported for autism and disputes the uniqueness of these findings. The minicolumnar changes provide a possible link to receptive field abnormalities and a useful clinicopathologic correlate to Asperger's syndrome.”

Source

This means that the cause of the syndrome is that in some parts of the brain the concentration of brain cells are less and more spread out (brain is “normal” in other areas) witch would lead to different behaviour. Although this would not explain why people with AS would be better in their area of interest comparing to a “normal” person (but it does explain why they are worse in stuff they don’t like).



“Lack of theory of mind (ToM) has been considered to be a key feature in Asperger syndrome (AS). The main aim of the present study was to determine whether an exclusively auditory input of ToM stories activated the same brain areas as demonstrated previously using visual stimuli. Eight right-handed otherwise healthy men with AS and eight healthy right-handed male controls participated in a PET activation study using auditory given ToM stories and stories about physical events for induction. Both subjects with AS and controls showed increased activation in the occipitotemporal area bilaterally and in thalamus during ToM tasks. Both groups also showed activation in the medial frontal area during ToM tests. However, this activation was more intensive and extensive in the control group, especially when a more sensitive analysis method was used. As a group, unrelated to the tasks, the AS subjects showed increased activation of the cerebellum. It was concluded that the activation pattern was mainly in agreement with earlier studies using comparable stimuli administered differently. There was no support for a right hemisphere specific dysfunction.”

Source

This would mean that when an AS person is using ToM he or she is activating more of the brain sector called cerebellum then a “usual” person would therefore thought patterns are different. No difference between right and left handed noted.