Highlights from Volkmar and Palphrey’s ‘Autism Spectrum Disorders’
Autism and related conditions (previously termed
the pervasive developmental disorders and more
recently the autism spectrum disorders [ASDs])
share their major similarity in the significant difficulties
in social development and interaction associated
with problems in communication and behavior.
These conditions have been the source of great interest
for decades but only with the official recognition
of autism in 1980, in DSM- III, did research
begin to increase (Rosen et al., 2021); over time this
increase has been quite dramatic, with several thousand
scientific papers appearing each year. Despite
this increase, research in some areas (e.g., aging in
autism; Piven et al., 2011) is quite limited but, overall,
very significant progress has been made in both
understanding and treating these conditions. (p. 492)
Autistic disorder (sometimes referred to as childhood
autism or infantile autism) is the prototypic
disorder of the group and the one that has been the
focus of most of the available research. Research is
much less extensive on the broader spectrum of disorders
(ASDs) and caution should be used in overgeneralization
of results from more “classic” autism
to this larger population.Initially described by Leo Kanner (1943), all
subsequent definitions have kept some degree of
continuity with Kanner, who emphasized two key
features: autism (lack of social interest/ engagement
from the time of birth) and what he termed
resistance to change or insistence on sameness (difficulties
with change, stereotyped movements). (p. 492)
Social- communication features are now
grouped in one category while the restricted interest
category has changed to include unusual sensitivities
but provides many fewer ways for a diagnosis
to be achieved and appears to differentially exclude
more able and less “classic” cases. (p. 493)
The exclusion of new diagnoses of Asperger’s disorder
cases (while grandfathering in older “well established”
cases) remains problematic. The decision to
exclude Asperger’s even as a subcategory of ASD
was unfortunate given the emergent data on validity
of the concept (e.g., Chiang et al., 2014) and the
wide public acceptance of the concept (Greenberg,
2013). (p. 493)
Probably the most influential theory of autism
was proposed by Simon Baron Cohen (Baron-
Cohen et al., 1985) and postulated that individuals
with ASD lacked a “theory of mind” (ToM) or the
inability to (simply termed) to put themselves in the
place of the others. In the ToM hypothesis approach
(Baron- Cohen, 1995), social difficulties are viewed
as a function of a basic difficulty in intersubjectivity
(i.e., understanding the mental life of self and
others). (p. 496)
Some of the problems suggestive of executive
functions difficulties in ASD include the behavioral
rigidity, difficulties in multitasking, and problems
with attention and forward planning (Ozonoff &
Schetter, 2007).The executive dysfunction hypothesis suggests
that these difficulties in forward planning and
executive functions are the core underlying problem
in ASD and result in both the behavioral and
social problems that define the condition (e.g.,
see Ozonoff & Schetter, 2007). (p. 497)
Weak Central Coherence Theory
In this theoretical model the core feature is
the perceptual- cognitive style in ASD that relates
to how a person processes diverse sources of
information and then processes it to form a coherent
and meaningful whole. This model posits that
in typical development there is a tendency toward
information processing that will pull together the
diverse pieces of information constantly available
to the developing child and construct them into
a coherent whole, thus allowing the child to grasp
“the big picture.” This model posits that in autism
this processing style is disturbed or absent, resulting
in an information processing style in which the
focus is on smaller parts rather than on the whole
and thus is more detail- focused (Firth, 1989, 2003;
Firth & Happé, 1994). More recently, the model
has been refined to suggest that persons with ASD
have superior local processing and poor (but not
always absent) global processing (Happé & Booth,
2008). One of the great advantages of this model is
that it can be used to account more fully for both
the social and nonsocial features of ASD (Happe,
1996), such as the interpretation of social cues in
context, the problems with circumscribed interests,
the tendency to focus on parts of objects, insistence
on sameness, sensitivity to change, and the occasional
person with ASD who has very detail- oriented
knowledge in fields like mathematics and engineering.
Kanner (1943) observed important aspects of
this style in his first description of autism, writing
that individuals with autism have an “inability to
experience wholes without full attention to the constituent
parts. . . . A situation, a performance, a sentence
is not regarded as complete if it is not made up
of exactly the same elements that were present at the
time the child was first confronted with it” (p. 246). (p. 497)
Extreme Male Brain Theory
Baron- Cohen (2002) argues that, on balance, females
tend to be more naturally empathetic while males
tend to naturally systemize. In this model it is suggested
that persons with autism present an exaggerated
(or extreme) version of this dichotomy,
presenting with typical systemizing and reduced
empathizing. It is noteworthy that in his original
report Asperger (1944) noted that all his cases were
males and that fathers had rather similar social difficulties
(i.e., this is a long- standing observation in
autism. In his original (1944) report Asperger stated
that “[t] he autistic personality is an extreme variant
of male intelligence. Even within the normal variation,
we find typical sex differences in intelligence.
. . . In the autistic individual, the male pattern is
exaggerated to the extreme” (p. 129). (p. 498)
“Social perception” refers to “the initial
stages in the processing of information that culminates
in the accurate analysis of the dispositions
and intentions of other individuals” (Allison et al.,
2000, p. 1). Additionally, social perceptions are
an ontogenetic and phylogenetic prequel to more
sophisticated aspects of social cognition, including
ToM skills. Successful social perception involves a
set of three distinct but interrelated social cognition
abilities: (1) individuating and recognizing
other people, (2) perceiving their emotional states,
and (3) analyzing their intentions and motivations.
Social perception, in turn, facilitates a fourth
and more sophisticated aspect of social cognition:
(4) representing another person’s perceptions and
beliefs, or “theory of mind.”(p. 499)
The social brain is now defined as the complex
network of areas that enables us to recognize
other individuals and evaluate their mental states
(e.g., intentions, dispositions, desires, and beliefs). (p. 499)Brothers (1990) emphasized
the contributions of the superior temporal sulcus
(STS), amygdala, orbital frontal cortex (OFC),
and fusiform gyrus (FFG) to social perception. (p. 499)
A flood of neuroimaging work in adult humans
(and increasingly in children and adolescents) has
revealed a small but remarkably consistent set of
cortical regions in and around the posterior parietal
cortex associated with thinking about other people’s
thoughts, or ToM: bilateral temporoparietal junction
(TPJ), medial PFC (mPFC), and posterior cingulate
cortex (PC). The mPFC, is recruited when
processing many kinds of information about people
(Amodio & Frith, 2006), whereas the right TPJ is
recruited selectively for thinking about thoughts
(Saxe & Kanwisher, 2003). (p. 500)
Early and longitudinal study will be critical
in defining brain phenotypes. This is because the
shape of developmental trajectories of brain functioning
in specific circuits will provide more detail
on the nature of the abnormalities than will analysis
of brain phenotypes in adulthood. Despite
much progress, there is still much to learn about
the early longitudinal changes in brain connectivity,
function, and temporal dynamics that support the
development of the ability to integrate a broad array
of emotional and social cues from multiple sensory
modalities (e.g., vision, touch, audition) in the service
of social cognition. (p. 502)
These diagnostic criteria have evolved during the
past 76 years and continue to evolve, yet impaired
social functioning remains a required symptom for
an ASD diagnosis. Deficits in social functioning
are present in varying degrees for simple behaviors,
such as eye contact, and for complex behaviors, like
navigating the give- and- take of a group conversation,
for individuals of all functioning levels (i.e.,
high or low IQ). Moreover, difficulties with social
information processing occur in both visual (e.g.,
Pelphrey et al., 2002) and auditory (e.g., Dawson
et al., 1998) sensory modalities. While repetitive
behaviors or language deficits are seen in other disorders
(e.g., obsessive- compulsive disorder and specific
language impairment, respectively), basic social
deficits of this nature are unique to ASD. Onset of
the social deficits appears to precede difficulties in
other domains (Osterling, Dawson, & Munson,
2002) and may emerge as early as 6 months of age
(Maestro et al., 2002). (p. 502)
The spectrum from mental health to mental illness is continuous
and not categorical— Mother Nature has not yet
read the DSM- 5. Thus, a dimensional, individual
differences approach is crucial to understanding
multimodal social cognitive abilities and their
development. (p. 504)
Post Author(s)
Review by Dr. Mark Zuccolo, The Neurodivergence Research and Education Society
References
Many articles and books referenced in the article can be found in the Neuroscience Library.
