Recent Findings on the Autistic Brain
Over the past few years, a number of studies have been published linking differences in brain structure and function to autism spectrum disorders. For example… scientists have noted that:
At a certain point in post-natal development, autistic brains are larger.
Testosterone may be linked to autism.
Certain portions of the brain, such as the amygdala, may be enlarged in autistic brains.
Certain parts of the brain may function differently in autistic people.
"Minicolumns" in the brain may be formed differently and be more numerous in autistic brains.
The entire brain may function differently in autistic people.
To better understand which of these findings is legitimate and which is most significant, I interviewed Dr. Nancy Minshew of the University of Pittsburgh. Minshew is one of the most prolific and best-known researchers in the field of autism and the brain. According to Dr. Minshew, "These different theories are not all so different."
The Autistic Brain is "Differently Wired"
What all of these brain findings have in common, Dr. Minshew explains, is that they point to autism as a disorder of the cortex. The cortex is the proverbial "gray matter": the part of the brain which is largely responsible for higher brain functions, including sensation, voluntary muscle movement, thought, reasoning, and memory.
In many autistic people, the brain develops too quickly beginning at about 12 months. By age ten, their brains are at a normal size, but "wired" atypically. "The brain is most complex thing on the planet," says Dr. Minshew. "So its wiring has to be very complex and intricate. With autism there's accelerated growth at the wrong time, and that creates havoc. The consequences, in terms of disturbing early development, include problems within the cortex and from the cortex to other regions of the cortex in ways that compromise language and reasoning abilities."
Minicolumns, which are small structures within the cortex, are also different among autistic people. Dr. Manuel Casanova, a researcher at the University of Kentucky, has found that autistic people have more minicolumns which include a greater number of smaller brain cells. In addition, the "insulation" between these minicolumns is not as effective as it is among typically developing people. The result may be that autistic people think and perceive differently and have less of an ability to block sensory input.
The Down Side of Unique Wiring
If autistic brains are wired differently across the board, is it a problem? Of course, for many people -- and in many ways -- the answer is "yes."
Says Dr. Minshew, "Autism really impacts behavioral function in the brain very broadly. It effects sensory, motor, memory, and postural control -- anything that requires a high degree of integration of information. The symptoms are most prominent in social interaction and problem solving because they require highest degree of interaction." In fact, she continues, "They're socially/emotionally far more delayed than anyone ever thought, even if they have a high IQ. Temple Grandin, a well-known speaker and writer with autism, says she's emotionally about 7 - 10 years old."
The Up Side of Unique Wiring
While social and communication skills may be compromised by unique wiring in the brain, other abilities are actually enhanced. For example, says Dr. Minshew, "Autistic people have a really stellar ability to use the visual parts of the right side of the brain to compensate for problems with language processing. This may be the basis for detail-oriented processing -- and may be a decided advantage!" In fact, as she describes it, "Control children can't find Waldo. Autistic children can."
What Brain Differences Mean to You
Autism may be described as a syndrome characterized by specific neurological differences. But what does that mean to the parent or teacher of a person with autism?
To start with, it provides an understanding of what's going on in an autistic person's mind. Says Minshew: "They think differently becaue their brain is wired differently. They think logically and predictably, but differently. It's as if they're colorblind. You wonder why someone doesn't stop at a red sign -- and it's because they can't see it. Teachers need to be taught this. When the teacher says "ok close your books and hop over to the door" and the child hops, the teacher feels mocked. She hasn't been mocked; she's been obeyed."
Understanding differences in the autistic brain may also provide hints for better communication. For example, since it may be harder for a person with autism to process multiple ideas, or to multi-task, it makes sense to "say less; give the facts; don't give a lot of tone of voice and gestures and distractions. You'd be surprised how many behavior problems are related to that. Remember that the child is dealing with facts, not concepts."
How Understanding the Autistic Brain May Improve Outcomes
Will a better understanding of the autistic brain lead to better treatments? Minshew thinks the answer is "yes."
"I think treatments are coming. Functional underconnectivity studies show that there are increased neuronal fibers; these studies are consistent. Now we need to find out whether, if we do a certain cognitive paradigm, we increase connectivity. It probably can be done. But these will be very different cognitive therapies than ABA. There's a time for behavioral therapy, and a time for stopping that -- to shift from learning rules to being flexible and acquiring interactive circuity. In autistic brains, circuitry is developing into adulthood -- but it's not developing in the right way, and it stops developing too soon. With the right treatment, though, it can be pushed."
Atypical sensory functioning in autism spectrum conditions
There have been studies of hypersensitivity to sensory responses in different sensory modalities, particularly vision and touch. The ARC was among the first to show superior visual search ability in people with autism or Asperger Syndrome and among their first degree relatives. We are testing if such sensory hypersensitivity is found irrespective of modality, using established methods from psychophysics. These include the measurement of sensory thresholds for detection of a stimulus, sensory discrimination between two stimuli, acuity, and adaptation. We are also relating sensory hypersensitivity to brain activity, using fMRI, and to genetic variation, testing for association with SNPs in candidate genes. Finally, we are interested to understand the relationship between the 'low-level' atypical sensory functioning in autism and the 'higher-level' cognitive differences (e.g., in empathy or systemizing).
New research has found common elements in the genetic factors behind autism.
A new breakthrough has found a number of common biological themes that underpin the genetics behind autism.
Research by the Center for Biomedical Informatics at the Children's Hospital of Philadelphia has identified common factors between a number of the gene alterations that play a part in the condition.
Dr Peter White, senior author, molecular geneticist and director of the centre, has highlighted the fact that groups of genes that have similar functions contribute to the risk of developing autism.
"This large study is the first to demonstrate a statistically-significant connection between genomic variants in autism and both synaptic function and neurotransmission," he explained.
Dr White explained that while each set appears only rarely, the similarity between the effects suggest that the same diagnosis could apply to a wide variety of different gene alterations.
Recent research published in the Journal of the American Medical Association found that children with autism often also experience difficulties in trying to meet their energy demands due to dysfunctional mitochondria.
Find out about Barchester's support for adults and children with a wide range of Autistic spectrum conditions.