Similar to the causes and origins of autism and Asperger's syndrome, the model of what autism really is brings its own continuing conjecture and debate. Amongst several competing theories are the under connectivity theory developed by cognitive scientists at Carnegie Mellon University and the University of Pittsburgh, Simon Baron-Cohen's extreme male brain theory, the lack of theory of mind, and the pre operational-autism theory.
The Extreme Male Brain Theory: The extreme male brain theory of autism, proposed by Simon Baron-Cohen in accordance with his empathizing-systemizing theory, suggests that autistic's have extreme forms of what he describes as the male brain: they are good (often very good) at systemizing, and very bad at empathizing. Poetry composed by people with autism would seem to challenge this idea, but the scientific validity of the idea is still under discussion.
The Pre-Operational Autism Theory: The pre operational-autism theory states that autistic people are those who become neurologically impeded at the pre operational stage of cognitive development, where much of information processing is at a holistic-visual level and largely musical and nonverbal. This also addresses the issue of the theory of mind where children (autistic and non-autistic) at the pre operational stage of cognitive development have not attained decentralization from egocentrism.
Monotropism: In this model of mind, mental events compete for and consume attention. In a polytropic mind, many interests have a moderate amount of attention put into them, while in a monotropic mind, the person's attention is put into a few more specialized interests. The theory argues that when many interests are aroused, multiple complex behaviors emerge, but if only a few interests are aroused, fewer—but more intense—behaviors emerge.
Under Connectivity Theory: Under connectivity theory theorizes that autism is a system-wide brain disorder that limits the coordination and integration among brain areas. With the aid of fMRI, it was seen that white matter, which connects various areas of the brain like cables, has abnormalities in people with autism. This theory may be related to the "lack of central coherence" theory proposed by Uta Frith, which suggests that children with autism are good at paying attention to detail but have difficulty integrating information from a range of sources.
Mind Blindness Theory: This theory says that the autistic person has "mind blindness", or the inability to create models of other people's thoughts. The typical example of this is the Sally-Anne test where the subjects have to try to determine what a third party's action will be. Some people with autism do not seem to fit this model, however.
Faulty Mirror Neuron Theory: In some instances, brain areas that are active during the observation of hand-movements are silent in autistic individuals. The activity is markedly enhanced in non-autistic persons. So the social deficits observed in autism could be the result of a faulty mirror neuron system, which could also prevent normal development of empathy.
Social Construct Theory: This is the belief that autism is not really a disorder, but instead is a social construct. That is, supporters of this theory do not believe autism exists at all; they believe (partly supported by recent reference to the rising cases of diagnosed autism) that autism is just the way some people are—that is, a part of the person's personality, which might explain the apparent difficulty in finding a model and a cure. This is further supported by the fact that autistic people have normal life spans and their condition often comes with advantages, not just disadvantages.