Intended for healthcare professionals

Clinical Review

Diagnosis of autism

BMJ 2003; 327 doi: https://doi.org/10.1136/bmj.327.7413.488 (Published 28 August 2003) Cite this as: BMJ 2003;327:488

Parents' perspectives add to our understanding of cognitive functioning in autism

A mother of a person with autism affirms in her communication to this
Journal "I often tried to tell my son's teachers that language is a second
language to him". Parents very often offer us useful insights on mental
functioning in the autistic spectrum disorders (ASD). Language, similarly
to other higher order abilities, is rarely if ever fully automated to the
level of a spontaneous ability in ASD. When listening to these children
and adolescents we perceive a lack of global control on fluid and prosodic
utterances. Many persons with ASD speak through an effortful process which
is probably run in a piece - meal "analytical" way every time the
individual tries to communicate. Seemingly in order to a simplify the task
of speaking, even some high-functioning individuals with AD concentrate on
partial elements of language, are slow in finding contextually appropriate
words, use a simple syntax and tend to exclude prosody. The production of
syntactically more elaborated, ready - made phrases, often derived from
the repetitive listening of videocassettes does not signal the acquisition
of a flexible, goal-calibrated grammar. Some individuals with ASD and an
average or above-average verbal I.Q. develop an intriguing expertise in
building up and verbally transmitting their knowledge about their
preferred topics, but the rich lexicon they show is usually confined to
these topics, while the pragmatic aspects of their language and their
social exchanges are usually impaired.

The process of "learning" entails the acquisition of new data and a
transformation on them. Both declarative and procedural knowledge require
an elaboration of the neurally processable material before proceeding to
storage. In the case of declarative knowledge, for example, an upward
movement toward the formation of categories brings about a clearer, more
reasoned view of our environment. Analogously, an integration of simple
procedures into more complex schemata of action allows us to be more
efficient every time we rehearse and apply those procedures. We appreciate
this in every field, from driving to diagnosing, to socially relating.

In the case of ASD, these processes of categorization and
automatization are probably hampered. It is also possible that the smooth
access to procedural and declarative neural reservoirs, where incoming
data are supposed to inform dedicated circuitries, is less efficient in
persons with autism. This could explain motor clumsiness (especially for
complex movements), difficulties in language, and, at least partially,
lack of spontaneity in interpersonal relationships, as social scripts must
themselves be automated through expertise, rehearsed and adapted online,
while acting. So, it may be the case that persons with ASD are capable
only of a partial transformation of inputs, especially of the more complex
ones, and have to adjust to the use of alternative procedures when
remembering, thinking and acting. Some high functioning persons with
autism speak of their ability to rehearse entire sequences of scenes they
observed, like playing a videotape in their minds, while they are unable
to comment or even mentally elaborate upon the same sequences in reality
and in real time.

Recent studies by Keysar et al. [1] and by Epsley et al. [2] suggest
that normal adults use their "Theory of Mind" abilities as an option, and
not as a permanently installed ability. An economic principle seems to
dictate the use of the lowest level of mental energies and the fewest
neural modules for a particular task: only a part of all our mental
faculties are used when we are manipulating perceptual, speculative and
motor data. Selective attention may be but one aspect of this regulating
principle, either in the form of focusing on a specific group of elements
in our attentional field and/or considering only the surface of them.It
may be the case that while persons without autism process information
similarly to the person with autism in certain circumstances, making a
sectorial and isolated use of brain circuits, an easy reversibility of
this kind of processing is what distinguishes normal functioning from
functioning in ASD.
So we use echolalia to keep in a stand-by position a phrase we heard after
our brain had already started processing another important mental task.
Once the latter task is accomplished, we are free to examine the meaning
of that phrase. We happen to apply our mindreading abilities and recognize
the necessity of taking into consideration our interlocutor perspective, a
few seconds after detecting that we have made an egocentric error in
judgment. In this latter case, additional neural circuits are activated in
order to reach a broader view and a deeper understanding of a particular
(social) situation. In a sense, this dynamic progression toward a wider
computing power, which is detectable even in normal adults, reflects
onthogenesis (the progressive maturation and enlargement of available
neural circuits during the development of the child, particularly along
the cerebello-prefrontal axis) and phylogenesis (the increasing
complexities of nervous systems, from lower species to humans).

We eumetrically avoid painful feelings, thoughts and insights, when
we make use of so-called psychic defenses. A basic role of the cerebellum
in the regulation of mental processes has been advocated recently [3, for
a review]. While a dysfunction of the cerebellum as a part of a wider
integrative system [4] could explain the above mentioned autistic deficits
in transforming experiential data into higher-order data and in accessing
them with rapidity and precision, a well functioning integrative system,
under the aversive influence of structures like the amygdala in the
temporal lobe could explain the unconscious barrage to uncomfortable
memories.

Temple Grandin, an introspective high-functioning person with autism,
affirms [5]: "In my mind there is no subconscious. Images are constantly
passing through the computer screen of my imagination".

REFERENCES

1. Keysar B, Lin S, Barr DJ. Limits on theory of mind use in adults.
Cognition, 2003, 89:25-41.

2. Epley N, Morewedge CK, Keysar B. Perspective Taking in Children and
Adults: Equivalent Egocentrism but Differential Correction. In press.

3. Habas C. The cerebellum: from motor coordination to cognitive function.
Rev Neurol (Paris), 2001, 157:1471-97.

4. Loddo, S. "The causes of autism and schizophrenia" Rapid response to
Szatmari: "The causes of autistic spectrum disorders" Electronic British
Medical Journal, 2003, http://bmj.com/cgi/eletters/326/7382/173#33854.

5. Grandin, T. Genius May Be an Abnormality: Educating Students with
Asperger's Syndrome, or High Functioning. Autism.
Http://www.autism.org/temple/genius.html, 2001.

Competing interests:
None declared

Competing interests: No competing interests

27 April 2004
Silvio Loddo
Child and Adolescent Psychiatrist
Neuropsichiatria dell'Età Evolutiva, AUSL n. 5 Oristano, Italia