The literature on specific aspects of Asperger's Syndrome is liberally embedded throughout the document. In this section I have limited the review to historical and general literature. This post summarises much of the information given in other sections, but brings together some of the current thinking on ASD causes, neurology and modes of diagnosis and management.

At the time of writing, Asperger's Syndrome (AS) is described as a developmental disorder on the Autistic Spectrum with abnormalities in social development and communication, accompanied by repetitive or obsessional behaviour or markedly narrow interests (Bonus & Assion, 1997; Bowman, 1988; Frith, 1991; Hjort, 1994; Tantam, 1992; Wing, 1981). It is increasingly recognised by paediatricians and child psychologists around the age of eighteen months to two years, when children appear to be on a different or delayed developmental path to their peers. As establised earlier, the diagnostic criteria (American Psychiatric Association, 1994; Gillberg, 1998) is based on deficiencies in areas including empathy, non-verbal communication, peer relationships, emotional reciprocity and central coherence, with abnormalities in intense focus, pervasive mannerisms, inflexibility and sensory sensitivities. Recently, some researchers have begun to view autism as a "different cognitive style" (Baron-Cohen, 2002, p. 186) and describe autism in terms of difference rather than deficit.

In terms of etiology, or cause, genetics clearly play a role, but this is also complex, appearing to implicate a collection of somewhat disparate genes (Constantino & Todd, 2003; Dawson et al., 2002; Folstein, Dowd, Mankoski, & Tadevosyan, 2003; Grice & Buxbaum, 2006; Muhle, Trentacoste, & Rapin, 2004; Schaefer & Mendelsohn, 2008). In addition, the appearance of symptoms of varying depth and combination on the Autism Spectrum suggests a significant interplay between genetic factors. The rise in numbers of people with diagnosed in recent years may be partially accounted for by increased awareness and definition of the spectrum (Lenoir et al., 2009), but other possible causes such as environmental factors, diet and vaccination side effects have been proposed and are still under investigation. Of these, the vaccination issue has gained the most exposure in the media. A study published in 1998 by The Lancet (Wakefield et al., 1998) drew links between the Measles Mumps and Rubella vaccination and its mercury-containing base and the appearance of Autistic symptomology in individual children. The article resulted in a marked decrease in vaccination rates worldwide and many parent groups seized upon a scapegoat for their children's problems. Twelve studies examining this issue were reviewed in 2003 (Wilson, Mills, Ross, McGowan, & Jadad, 2003), with all indicating no link, and a further large-scale survey in Canada (Fombonne, Zakarian, Bennett, Meng, & McLean-Heywood, 2006) showing no association with either ethylmercury or the measles antibody and in January 2010 after an investigation by the British General Medical Council, the Lancet took the extraordinary step of withdrawing the original article (Dyer, 2010).

The central mechanism for autism is currently unknown despite considerable effort from researchers in neurochemistry and neurophysiology. Certainly there are brain differences in adults and adolescents with autism but much of these are related to connections that form throughout childhood. However, autism is a disorder of development and the reasons that this development takes a different course remains elusive. A number of "theories of autism" have emerged over the years that attempt to place a single aspect of the condition at its heart and explain the various traits as symptomatic. Candidates for a central mechanism have included Theory of Mind (Happe & Happe, 1994), Extreme Male Brain (see below) (Baron-Cohen, 2002), Weak Central Coherence (Frith, 1989) and Enhanced Perceptual Functioning (Mottron, Peretz, & M�nard, 2000), however none of these theories have adequately accounted for all three of the triad of impairments the condition and its various manifestations. In addition, WCC and EPF are partially contradictory, and significant doubt has been cast on Theory of Mind deficits by Klin's Enactive Mind Theory (2003)..

Certain autistic traits may be useful to the individual or group in collaborative situations (Gray & Attwood, 1999; Hawkins, 2005, p. 98). Some important aspects of this are discussed in an earlier post. Creativity in AS individuals is frequently associated with mathematics, physics, computing - fields where order and patterning are of particular importance and obsessive focus is almost a requirement. However recent studies are also beginning to identify a high incidence of AS among the artistic community. Fitzgerald, (2005) goes so far as to suggest that the syndrome, separate from savantism, may be involved in the success of some creative geniuses and identifies a number of artists, writers and musicians, among them Mozart, Gould, Bartok, Orwell, Yeats and van Gogh, whose biographical and autobiographical accounts exhibit sufficient ASD traits to earn them a posthumous diagnosis. Anecdotal evidence suggests that there is also significant prevalence in creative team workers in the film industry (Garnett, 2006, private communication).

Much research into high functioning autism has focused on imbalances between cognitive intellectual abilities and social or "emotional intellect". Professor Simon Baron-Cohen believes that high functioning in particular fields such as music, computer programming or maths is attributable to high systematising, or the drive to understand and exploit systems or patterns (Craig & Baron-Cohen, 1999).

The Empathy Quotient, Systematising Quotient and Autistic Quotient questionnaires developed at Cambridge University's Autism Research Centre provide an opportunity to screen for traits and characteristics on a continuum that has been extensively tested in AS and control populations (Baron-Cohen & Wheelwright, 2004; Baron-Cohen, Wheelwright, Robinson, & Woodbury-Smith, 2005; Wheelwright et al., 2006; Woodbury-Smith, Robinson, Wheelwright, & Baron-Cohen, 2005). This research has shown that people with Asperger's Syndrome have "extreme Systematising" or "Extreme Male" brain types where the balance between systemizing and empathising is strongly shifted away from empathy, and a high "Autistic Quotient" (Baron-Cohen & Wheelwright, 2004). He does indicate however that his tests are indicative rather than diagnostic; an "extreme S" and high "autistic quotient" does not make a person AS or autistic, rather a person with AS will exhibit high AQ and "extreme S" characteristics.

The technical literature in Asperger's and autism is a strongly growing resource for those who have access to academic journals and texts, however accurate and up to date research is largely unavailable to parents and carers and to AS individuals. There are some excellent books, particularly through Jessica Kinglsey Publishers, but books are expensive and can be difficult to track down. The Internet redresses this in some respects, particularly with a proliferation of forums and sites maintained by support organisations, however the quality of information is frequently suspect and on occasion driven by political and commercial imperatives. While the scientific community is calling for first person accounts of what it is to be autistic, the autistic community is in clear need of accurate and accessible literature detailing up to date research on autism, including both its positive and negative aspects. �As has been indicated earlier, this thesis is firstly aimed at an academic audience, but it is also intended to be published on-line as a point of departure for the general public who do not have access to university libraries and journal subscriptions. While it is clearly not possible for copyright reasons to link to the content of my bibliography, it will at least indicate the work being done in the field and the names of some of the notable researchers.

Related Posts

1. Surveys: The Cambridge Personality Index surveys - AQ and EQ
2. What is ASD?: A brief overview of the Autistic Spectrum and the traits associated with it.
3. Statistics: Information on prevalence and distribution of ASD in the community.
4. Psychological stress: Asking people to observe and report on their cognitive selves can pose ethical dilemmas
5. Speaking, Hearing, Seeing: People with Asperger's and HFA often have unusual ways of speaking, hearing and seeing interpersonal communication modes.
6. Why Autoethnography: In addition to building on reflective practice traditions in music research, autoethnography responds to calls from psychology researchers for the "insider perspective" in autistic persons.
7. Pathetic Empathic: Empathy in Asperger's is affected in complex ways, with partial impairment but significant differences in experience.