Is Autism a cognitive ability, a cognitive disability or a different way of functioning?
The term autism has been continuously changing over time. Its history dates back to 1910 when the Swiss psychiatrist Eugen Bleuler alluded to autistic symptoms for the first time, and associated them with schizophrenia. Nonetheless, in 1943, the Austrian physician Leo Kanner outlined autism as an independent category, and one year later the Austrian doctor Hans Asperger catalogued Asperger Disorder as a new pathology. Both conditions differed from schizophrenia in their onset. Schizophrenic children displayed a normal development until the beginning of school years, while autistic kids presented symptoms since birth.
Lately, the Diagnostic and Statistical Manual of Mental Disorders (DSM-III and DSM-IV), and the International Classification of Diseases (ICD-10) included autism as a Pervasive Developmental Disorder, and divided it into five subtypes: Autistic Disorder, Asperger’s Disorder, Childhood Disintegrative Disorder, Rett’s Disorder and Pervasive Developmental Disorder Not Otherwise Specified.
Finally, the DSM-V and the ICD-11 conceptualised autism as a spectrum, cutting out the labels of its previously established subtypes.
This essay presents two perspectives of the Autism Spectrum Disorder: a medical model proposed by the DMS-V and the ICD-11, and a neuropsychological model based on cognitive theories. It aims to critically appraise to what extent these two perspectives explain the features of Autism Spectrum Disorder in terms of strengths and weaknesses in cognitive functioning.
Overall, Autism Spectrum Disorder (ASD) is the umbrella term used to describe a set of neurodevelopmental conditions which share three main characteristics: difficulties in social interaction, impairment in verbal and non-verbal communication, and stereotyped, repetitive, restricted patterns of behaviour and interests.
As mentioned before, ASD is a dynamic term that has evolved throughout history. Different fields offer different explanations of this disorder, aiming to clarify its nature.
The medical model uses manuals to detect ASD. The DSM-V and the ICD-11 indicate that the impairments must manifest in the early childhood, during development, preferably before three years of age, even if they are evident only in older years with the change of social demands. They adopted a model called the Triad of Impairments, developed by the English psychiatrist Lorna Wing in 1979, and used it as the base for creating the new diagnostic criteria.
As its name suggests, the Triad of Impairments outlines three core areas that are affected in ASD: social interaction, communication, and imagination. This model offers a description of the key symptomatology of the spectrum, and it prevents clinicians from using it as a classification system, stressing that these impairments manifest differently in each individual and that they present different levels of severity and intensity.
The impairment in social interaction alludes to the difficulty in establishing interpersonal relationships. The impairment in communication involves the pragmatic property of language; in other words, individuals fail at using language to communicate with others, transmitting and receiving messages. The impairment in imagination refers to the difficulty in abstract and symbolic thinking.
To what extent does this system allow clinicians to identify, not only weaknesses but also strengths in people with ASD?
The neuropsychological model proposes several cognitive theories that attempt to explain ASD and guide its assessment and further intervention. Unlike the medical model, the neuropsychological model does not list a set of deficits found in ASD but disentangles the cognitive processes that underlie autistic behaviours, in order to comprehend its nature. This paper focuses on the three most relevant cognitive theories in the literature.
The Theory of Mind theory
Simon Baron-Cohen hypothesized that the deficits found in autistic children could be explained by impairments in Theory of Mind (ToM). The author defined ToM as the skill that helps make sense of others and of oneself, allowing to speculate other people’s mental states, such as their beliefs, desires, intentions, imaginations, and emotions, as well as our own, in order to understand, explain and predict behaviours.
Surprisingly, not all participants presented these features. Unlikely to what was expected, ToM difficulties were not universal along the autistic spectrum, and the levels of the deficit were extremely variable; some individuals would have mild, others moderate, and others severe difficulties, while others would show no impairment. Subsequently, many researchers replicated Baron-Cohen’s studies in order to comprehend this variability. Nowadays, there is still no consensus in weather ToM impairments in ASD represent a deficit, or a delayed ability, or a skill that operates differently in the ASD population.
The Weak Central Coherence theory
Visual processing is dissociated into two main cognitive styles: global processing and local processing. Global processing or central coherence is the processing of information in an integrated, coherent way, perceiving the stimuli as a whole, and placing them in a context. On the contrary, local processing is the tendency to perceive the parts and the details of the stimuli prior to integrating them as a unit.
The majority of the population processes information globally, while ASD individuals process it locally. This is the premise of the Weak Central Coherence theory. Both, global and local cognitive styles, are attentional and perceptual biases. In the first one, the global analysis takes place prior to local analysis, and in the second one, the local analysis takes place prior to global analysis. ASD population processes information with a local precedence filter, while the non-ASD population processes information with a global precedence filter. Both are different, alternative ways of processing information, and as stated, both constitute a type of bias.
The Executive Functions theory
The last cognitive theory in this paper explains ASD in terms of an underlying dysexecutive syndrome. It has been observed that ASD participants score less well than non-ASD participants in executive function tests. However, executive functions were impaired in different levels across the spectrum and that the difficulties increased as age increased and as IQ decreased.
This theory is, however, the most inconsistent one of all. Firstly, the dysexecutive syndrome is not an exclusive manifestation of ASD, but rather a common condition in many neurological and developmental disorders. Secondly, results in the literature are extremely fluctuating. Disabilities in executive functions are immensely variable across the spectrum, and even some autistic people do not present EF impairments. Lastly, comorbidities play a very important role in EF performance. It has been seen that intellectual disability, learning difficulties and mood disorders, which are very common in ASD, tend to affect the scores, being very complicated to adjust the results for comorbid pathologies.
Final conclusion
Autism Spectrum Disorder is a frequent though misunderstood condition. At first sight, it might seem that all theories complement each other. Even though being this undeniable, it is also true that each theory has a different epistemological basis, and this will impact greatly on the conceptualization of the spectrum.
There is consensus in the literature about the main symptomatology of ASD and in the variability of its presence along the spectrum. However, some theories consider these symptoms as impairments, others as delayed skills, and others as different ways of functioning.
Throughout history, individuals considered as abnormal or different have been categorised as ill, needing treatment in order to become normal or equal to the majority. This leads to the philosophical question of what is normal and what is abnormal. The medical model in a rather simplistic way tries to identify deficits that must be fixed. A more appropriate approach is the one that accepts diversity and uniqueness, helping individuals to develop as honourable human beings, with an honourable place in society.
References
Baron-Cohen, S. (1999). Autism and 'theory of mind'. In J. Hartley & A. Branthwaite (Eds.), The Applied Psychologist (2 ed.). Buckingham: Open University Press.
Jolliffe, T., & Baron Cohen, S. (1999). A test of central coherence theory: linguistic processing in high-functioning adults with autism or Asperger syndrome: is local coherence impaired? Cognition, 71, 149–185. doi:https://doi.org/10.1016/S0010-0277(99)00022-0
Ozonoff, S., Pennington, B., & Rogers, S. (1991). Executive Function Deficits in High-Functioning Autistic Individuals: Relationship to Theory of Mind. Child Psychology and Psychiatry, 32(7), 1081-1105. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1787138.
World Health Organization. (2018). International Statistical Classification of Diseases and Related Health Problems. 11. Retrieved from https://icd.who.int/browse11/l-m/en