In an article published in December 2009 in the Neuroscientist titled “The Medial Prefrontal Cortex and Integration in Autism,” Dr. Dorit Ben Shalom, a researcher from Ben-Gurion University of the Negev, Israel offers a novel conceptual framework of known atypicalities in individuals with autistic spectrum disorders (ASD).
The prevailing approach has tended to focus on deficits in the capacity for “Theory of mind” (roughly, “emotion”) as the main hallmark of the ASD diagnosis. Ben Shalom asserts that more domains contribute to the deficits frequently seen in these disorders. She proposes a total of four domains that are substantially impaired in most or many individuals with ASD, which include the following in addition to “emotion”:
- Memory
- Sensation-perception
- Motor skills
Ben Shalom’s basic premise is that the impairment consists of an “arrest” in the development of one level of processing in each domain. She draws from the previous work of Damasio who in 1995 described three levels of emotion processing in the brain: basic, integrative and logical. Ben Shalom extends the concept to perception, memory and motor skills. She proposes that in people with ASD there is a developmental arrest at level one (basic) and that the integrative level (two) is never reached (although logical compensations (three) are possible in people with high functioning ASD).This might explain phenomena frequently seen in individuals with ASD, such as difficulties with episodic memory (memory domain), sensory integration problems (perception domain ) and dyspraxia (motor domain).
Dr Ben Shalom hypothesizes that part of the core impairment lies in a specific brain location – the Medial Prefrontal Cortex that subserves the integrative functions of all four domains. A part of the article includes a graphic summary of the main anatomic hypothesis of the article (page 8).
Commentary
As the integrative functions normally develop at age 1-5 years, this article highlights the dire need for early diagnosis and early intervention for children with ASD. It also calls for a closer evaluation of all four domains (emotion, memory, perception and motor skills) as part of the diagnostic assessment of individuals with suspected ASD. While in some instances the diagnosis is clear cut, in many others establishing an ASD diagnosis becomes very difficult. Frequently the evaluating clinician struggles to establish a differential diagnosis between ASD and other diagnoses such as Bipolar Disorder, Depression, Attention Deficit Hyperactivity Disorder (ADHD) and Tourette’s Syndrome. Extending the scope of the evaluation to all four domains rather than the narrower scope of DSM4 will result in earlier, more accurate and more successful diagnosis and treatment.