Asperger’s Syndrome Smell Test

The Asperger’s Syndrome Smell Test is typically used to ascertain whether a child fits the Asperger’s Syndrome diagnosis. Because Asperger’s Syndrome typically is a deficiency in right-brain processing, the sense of smell can be used to identify this.

The sense of sight and hearing can be labelled as left-brain senses in that in order to make sense of what we perceive we must form patterns in these senses. What we hear is a series of sounds and we form patterns in these sounds to identify words, music, background noises etc. Similarly with what we see. To make sense of the visual information we have to form the basic sensations of brightness and colour into images. We don’t usually form patterns in what the feel, see or smell, however. We just experience the sensations. Blind people make patterns out of what they feel in order to identify objects. People who are trained in, for instance, wine tasting may make patterns out of what they taste and people trained in subtle perfumes may make patterns out of their sense of smell. However, for most people the sense of smell exists as a sensation.

I typically perform the Asperger’s Syndrome Smell test in the following way.

The child (usually I do this test on children up to around 18 years old) sits in one chair and the parent (usually the mother) in an adjacent chair. I tell the mother that she mustn’t comment. I then bring out some scented bottles keeping the labels hidden.

The first smell is usually a strong smell such as lemongrass. I pass the bottle in front of the child and ask them to smell it. I tell them that it’s not about identifying the smell although if they can that’s fine. I then pass the bottle in front of the mother.

The next one is typically a more subtle smell such as rose and as I pass it in front of the child I ask them “is this is the same smell or different; stronger or weaker?” A normal response would be that the smell is different, but typically Asperger’s Syndrome children will say something on the lines that it’s the same smell but stronger or weaker, or that they can’t tell if it’s the same or not.

I then pass it to the mother with the comment that she is not to say anything.

The next smell is typically lavender, and the same comment – “is this the same as the other smells or different; stronger or weaker”. Again the comment from someone with Asperger’s Syndrome will be different from a normal child.

The mothers are usually surprised or even shocked as the smells are so obviously different and I point out the problem is not with the sense of smell as such but with the brain’s identification of the smells.

Interestingly, a similar result has been found in psychopaths, who also suffer from right-brain deficiencies.