Sunday, 12 June 2011

Cry baby

The little angelic face looks up at you. The lip starts to wobble.. the eyes start to water... and then the tears start to flow. Anyone who has regular contact with young children will know all about crying. Whether it be crying at 3am to indicate feeding time or crying because of a wet nappy or just crying for the sake of getting some all important attention from mum or dad (perhaps because your older sibling has taken your favourite toy..), crying serves an important communicative function to the young infant and beyond.

Believe it or not there are said to be different types of crying in infants* (*not an endorsement) modified by things like age. Because crying is one of the first communicative tools of the young infant - probably the only aside from what comes out the other end, (ahem!) - it has also been the topic of some interest in various attempts at early screening / diagnosis for a variety of things including hearing loss and sudden infant death syndrome (SIDS). Cri du chat syndrome is perhaps the most famous condition associated with crying; whereby the distinctive 'cry of the cat' provides some clue to the presence of this rare genetic condition (which has been reported to be co-morbid to autism in rare cases).

I have been brought to the topic of crying because of this study which recently appeared suggesting that there may be some subtle differences in the presentation of crying and related indications of distress in young children with autism compared to control participants. It's not the first time that crying has been studied in relation to autism. The previous studies however have been focused more on things like what happens when the opiate antagonist naltrexone is used in autism (the effect being slightly bi-directional depending on the study you look at) and other facets such as crying during sleep. I remember publishing a study a while back now where infantile colic was reported in some cases of autism, particularly Asperger syndrome. Knowing what I know about colic, I would perhaps imagine that this might also be a contributor to infant crying in, and outside of autism.

Back to the study in question. At least two of the authors on this paper have been looking at crying in relation to autism before. Their previous study suggested that episodes of crying from children with autism have a higher fundamental frequency (sound) than either typically developing or developmentally disordered children. They suggested that because of this higher frequency, the cry from a child with autism was perceived with more 'unease' to listeners. The recent study adds to these initial findings in that children with autism presented with more severe 'distress' cues in their posture and facial expressions alongside their crying patterns. The collected findings suggest that crying and distress in young children with autism might be both different compared to non-autism controls and also considered more distressful. Higher fundamental frequencies of crying have cropped up in the literature before, not least when it comes to looking at pain and crying. This study of crying after the Guthrie test for PKU suggested a similar pattern. Whether the two examples necessarily have the same reason is not known.

Whilst I think it is important to step back from these findings and bear in mind the relatively small numbers of participants involved in these studies, I find myself intrigued by the suggestion of differences in crying according to autism diagnosis or not. If we are to assume that crying is one of the beginnings of communicative language as some have suggested, there may indeed be some merit in looking more closely at crying as a possible early diagnostic aid. The added bonus being that such analysis is non-invasive, objective (insofar as the various sound technologies doing the work) and I would assume fairly quick and easy to undertake.

And now in order to test your mettle... a song accompanying the adventures of Hazel, Fiver and Bigwig.