Five years ago I wrote an opinion piece for the SPECTRUM (then SFARI) Autism website. I doubt that the message I wanted to get across – did.
We’ll reserve the top space for facts about the remote biological causes of autism. You could list an impressive number of risk factors here, such as susceptibility genes, and differences at the cellular level and differences in the size, activation and connectivity of brain structures, for example.
The space at the bottom is for all the behavioural observations,and performance on neuropsychological or psychometric tests. Behaviours reported by parents, behaviour assessed by questionnaires or interviews would be listed here as well. There is a huge amount of data: for recognition of faces alone, there are hundreds of papers.
The middle space between the two lines is the interesting one. It’s the ‘cognitive thing’. This is for ideas about what is different about the mind of someone with autism — and the core of my obsession.
Here’s a hard question: How does an individual find meaning in the world and act on the world? Answer: Through cognitive mechanisms that allow the individual to learn and to adapt in its environment. These mechanisms have a basis in the brain and have been honed by evolution over millions of years. For the individual they come for free as as start-up kits and they are active right from birth.
By the way, in this framework the term ‘cognitive’ describes everything that the mind does, consciously and unconsciously. It does not just refer to perception, attention, memory, reasoning. It refers to all aspects of mental life. And this certainly includes emotion, motivation, reward learning.
The cognitive level is also the space for imagination and controversy. Here we can’t observe and measure facts; we can only propose hypotheses. Of course they have to be amenable to being tested both on the biological and the behavioural level. It seems to me that in our state of ignorance, we might as well be bold. I have already inserted two of my favourite hypotheses to explain what is different about the autistic mind, mentalising and detail focus. I hope you will put forward your own hypotheses.
The mentalising hypothesis is very bold. It proposes that we are all born with a social GPS. The GPS tracks what others think and feel from moment to moment. This allows us to orient ourselves in social space without having to consciously think about it. Autism means not having this GPS, but instead having to rely on a map. This works, but is slower and more effortful. There are many tell-tale signs in behaviour and in the brain that seem to support this hypothesis.
Autism isn’t just about social communication. It is also about having a way of thinking, which can be described as ‘detail focussed’. The idea is that autism involves sticky attention to small parts at the expense of attention to the bigger picture. Thus local sensations can become overwhelming. This can be rephrased as giving less weight to prior expectations that prepare you to perceive a particular thing, and instead giving more weight to incoming information, both signal and noise.
We need such bold hypotheses. Here’s why: Behavioural and biological data only become meaningful if they can be explained in terms of what the mind does. Understanding that a child lacks a social GPS is far more helpful to a teacher than knowing that he or she has a particular genetic abnormality (biological); or tends not to look at eyes (behavioural). Likewise a teacher can understand that a child who is overwhelmed by bitty information may be terrified by the smallest changes in his or her environment.
We now have a structure that we can use to lay out what we have already learned about autism. I have drawn lines on Post-it notes, but if you want to insert all the facts that are already known, you will need a very large sheet of paper!
The holy grail of autism research is to identify the commonalities of the autism spectrum. These commonalities should lead to defining cognitive phenotypes. Then it will be possible to trace causes of autism from genes to behaviour.
We know a lot already, but how can we pull the existing findings together? We need to find a common pathway — the critical part in the system that is always affected, no matter which of the numerous genetic and environmental risk factors have placed an individual on the autistic spectrum.
If we were to find a common pathway, this would define a distinctive property of the brain that is critically different in autism. The common pathway forms a node in a network of possible mappings: It pulls together all the strings from the data that are already available and from the data that are not yet available, but can be predicted.
If we can find a node at the cognitive level, animal models become more informative, for example. This is because one can look beyond behaviour, which is obviously very different in mouse and man.
To me there is something very appealing about pulling together the strings in a common pathway. No wonder I’m obsessed with this cognitive thing.
There is a thorny point here: The node would pinpoint both normal and abnormal function. But isn’t this too black and white? Isn’t everyone ‘a bit autistic?’
I happily agree with this at the behavioural level, where one thing always shades into another. A measure of amount of eye contact, for example, will vary continuously across different individuals — we can only make an artificial cut-off point to define what is ‘abnormal.’ The same goes for the biological level: If you assess neuro-chemical levels, you will get a continuous distribution, with clinical groups tending to lie at one extreme.
At the cognitive level, however, it is admissible to use categorical distinctions. We are free to theorise that there are functions that the typically developing mind automatically performs, which the mind of a person with autism performs in a qualitatively different way, or not at all — and vice versa.
So here’s my message: We shouldn’t despair of ever finding clarity in the ever more complex world of possible biological causes and dimensionally varying behaviours. If we focus on the mind, we can make sense of the enormous complexity by testing daring hypotheses that can pull the strings together.