Study Links Synaesthesia to Autism

Researchers at the Autism Research Centre at Cambridge University set out to test the idea of there being a link between synaesthesia and Asperger’s syndrome after finding that anecdotal evidence suggested there was.

They asked 200 study participants, including 97 adults without autism, and 164 adults diagnosed with high-functioning autism (or Asperger’s syndrome) to fill in questionnaires so they could attempt to measure synaesthesia and autism traits.

The study found one in five adults with autism spectrum conditions – a range of related developmental disorders, including autism and Asperger’s syndrome – had synaesthesia compared with about 7% of people with no signs of the disorders.

More from BBC News Health:

“Prof Simon Baron-Cohen, who led the research, told BBC News: “Synaesthesia involves a mixing of the senses and it’s a very subjective private experience, so the only way we know it’s happening is if you ask people to report on their experiences.

“And what this new study has done is ask people whether they experience synaesthesia, for example where a sound triggers the experience of colour or a taste triggers the experience of colour, and finding that these unusual experiences are actually much more common in autism than we previously knew.”

The research, to be published in the journal Molecular Autism, suggests that while the two conditions might appear distinct, there could actually be some underlying similarities in brain connectivity.

Hyper-connectivity

Synaesthesia seems to involve unusual connections between brain areas not usually wired together, accounting for the jumbling up of the senses.”

It’s interesting that people can be born with ‘hyper-connectivity’ of the senses. But what is more interesting is people who develop this later in life after an injury or some type of stress. More on Smell and Taste from the New York TImes:

“Taste and smell together are the so-called chemical senses, meaning that stimuli associated with them are chemically based. In many respects the sense of smell is mysterious–not only because little is known about its operation as yet, but also because most people are insufficiently aware of its importance. When people are asked what sense they would be prepared to do without if necessary, smell comes at the top of the list and sight at the bottom. This is a debatable choice, given that smell plays a significant part in many psychic processes and behavior patterns. Smell is essential for the operation of the sense of taste; it affects one’s sex life, motivation and memory processes (including learning, health and feelings of security and well-being); and it has an alarm function in life-threatening situations (for instance, in detecting gas fumes, etc.). What is more, in “competition” (that is, when several senses are stimulated simultaneously), the nose often comes out on top. A beautiful-looking apple that smells rotten does not whet our appetite.”

However, our senses can also be tricked, because just like, for a person who is not chemically intolerant, the sight of a seductive looking bottle of designer perfume can induce feelings associated with elegance, luxury and beauty; furthermore, inhaling the scent, itself, can invoke memories that are associated with good and ugly memories. But, for these people, it goes much deeper than that: the effects from breathing in, and the chemical-to-skin contact with these chemicals, some of which are known carcinogens, neoro-toxins, endocrine disrupters and respiratory irritants, may not be immediately noticeable for years to come. Except, of course, this isn’t the case for those unfortunate chemically sensitive individuals unlucky enough to be caught in the airborne-fragrance drift of someone wearing such products… toxin induced symptoms can be detected immediately, or later, as is the case with delayed reactions. On the one hand, we have the smell–and for some of us, there is also the taste–of fragrance, while on the other hand, we have the physical reaction; whether that be an allergic reaction, a respiratory system reaction caused by inhaling fragrance chemicals that act as irritants to the air-ways, or the body’s toxic load reaching its limit.

But what does that mean for those of us who can taste fragrance before, or without actually, smelling it? Is this a case of Hyper-connectivity, the same as for someone on the spectrum? Or is it different?

Can you taste chemical odours? 

More on Syneasthesia

BBC Health News: Word-taste synaesthesia: Tasting names, places and Anne Boleyn

Blomsbury Journals: Inhaling Memories: Smell and Taste Memories in Art, Science, and Practice (Full text must be purchased)
UKSA: UK Synaethesia Association
Synaesthesia & Sensory Integration Lab: Dr Julia Simner

Oxford University Press: Oxford Handbook of Synesthesia (Includes Google Preview of Chapter 1)

Blog: A Writer who has High-functioning Autistic Savant Syndrome: Thinking in Numbers The Blog of Daniel Tammet

Neuroscience and Biobehavioral Reviews: Sensory substitution as an artificially acquired synaesthesia. Ward, Jamie and Wright, Thomas (2012)

Study from the University of Sussex: Touch synaesthesia in the phantom limbs of amputees. Goller, Aviva I, Richards, Kerrie, Novak, Steven and Ward, Jamie (2013)

An Artist’s Blog: Water Colour Candy