Sensory Processing Difficulties

Difficulties with sensory integration (now often referred to as sensory processing 'disorder' or SPD) are common in individuals with Tourette Syndrome or autistic spectrum disorders (ASD). These difficulties are of particular importance to educational progression and in speech, language and social development and functioning. Although recognised by educators (and educational psychologists) as a separate 'disorder' in the case of SPD and as a comorbidity in ASD, there is a poorly-understood reluctance to acknowledge this in Tourette Syndrome, a neuro-developmental disorder as common as ASD.


Most people are aware of the tendency for autistic individuals to not look at other people's eyes (the oft used phrase here is 'look into'). There is much confusion about the causes of this behaviour but an unwillingness to listen to what those with the disorder say about it. There is a similar tendency in TS. Studies have shown that, in many autistic subjects, when their eye movements and gaze direction are tracked digitally, they tend to focus more on the mouth than the eyes. A significant part of this mouth-directed visual preference is due to the individual needing to watch the lips of a speaker in order to improve their understanding of speech as they may have difficulties with comprehending speech through audible sensory input alone. This is of course well-known among people with deafness. 


An individual who shows a reluctance to look into your eyes, is therefore, not always shying away from 'social contact' as is often thought (because they are autistic). In autism there do appear to be difficulties also with the intensity of mutual visual-gaze which appears to induce an overly intense emotional response in some. There is also evidence that some individuals with sensory integration problems may find the continual movements of other's eyes to be a source of sensory stress. Those with TS and/or SPD may also seem to avoid eye-gaze because they are lip-gazing.


Many special educational needs teachers will persistently tell an autistic child "look into my eyes when I'm talking to you" and to further compound the transgression by doing the immensly annoying (to the child) gesture of pointing to their own eyes with their two forked fingers! It really is not helpful to the SEN child with these difficulties to undergo considerable effort and frustration in attempting to comply with this seemingly pointless and inconvenient requirement. Perhaps it's so others wil be able to say 'look how he/she is progressing' they have much better eye contact now! It is rather like the insistence that used to be prevalent in many schools for the deaf when they forbid the use of sign language (this was almost universal at one time) in order to'encourage' the child to learn to speak verbally, purely for the convenience of other 'hearing' individuals who did not wish to learn sign languages or were unwilling to provide the necessary accommodations to properly 'include' deaf children. This is not merely an issue of arrogance. For many children it removed the best channel for rapid development of communication and learning with the result that many deaf children became severely 'learning delayed'. More importantly, for many, they did not develop their speech and language abilities sufficiently during the normal period of early neuro-developmental plasticity of the brain which, once passed, precludes ever fully achieving their original language potential and thus experienced an impairment throughout their lives.


Another aspect of sensory processing difficulties in children with ASD, TS and also 'ADD' is that they may find it difficult to hear well when they are exposed to other ambient sounds or visual input (this may also apply to the tactile sense). Conversely they may not be able to read if you are talking or process visual input effectively. This raises specific concerns about the over-use of IT and audio-visual teaching aids which may represent a 'sensory onslaught' to such indivivuals. Another often-ignored problem is the use of low-frequency (50-60Hz) flourescent lighting in the teaching environment or at home. To an individual with SP difficulties these can represent something akin to a disco stroboscope as they can often perceive the flickering. The same problem arises with using many desktop computer screens that contain flickering light sources. Television with low screen refresh rates may also represent a source of sensory over-stimulation. Experiments in schools that involved removing standard flourescents and replacing them with high-frequency (300Hz) versions resulted in improvements for many SEN children but, more remarkably, improved 'behavioural' problems in the non-SEN children also! For children with these difficulties, replacing the lighting in the area where they study (and live) may bring benefits. Incandescent lights are a cheap option in bedrooms and for desklights for homework etc. The impact of newer LED lighting has not been properly evaluated in this context. Laptop computers and tablets tend not to have flickering screens although for many their expense is an issue. A big problem for older individuals with sensory disabilities, is that although many assistive and useful technologies are now available, they often have considerably fewer (or no) opportunities for earning even a living wage and for purchasing those technologies (iPads have been used with great success in helping with several neuro-developmental disorders including autism but many families cannot afford them). For those with TS and sensory problems computers may not always help. Keyboards in particular may present difficulties. Unlike handwriting where the action is direct - the text appears immediately at the tip of the pen precisely where they are looking, keyboards involve selecting and pressing multiple keys in a different position and plane to the text being produced. Many people have finger tics and obsessive-compulsive behaviours that are provoked or exacerbated by a "tray full of plastic buttons" and a mouse and also the complexity of the many buttons and menus of the software itself. Normal computer monitors are 'backlit' which may also reduce the ability to read for some with sensory difficulties. The latter are often actually better able to read from paper/printed media or from newer eReaders (such as Sony Reader or Kindle) which use a non-illuminated background and well-defined eInk text.


For the child with Tourette Syndrome their sensory difficulties are compounded immeasurably by having to suppress or control their tics during class or examinations where they are expected to sit still and quietly for extended periods, a 'tall order' in itself. They will often concentrate so hard on achieving this that they will not be able to focus their attention on the task at hand, read written material or listen to the teacher effectively or more importantly perform academic tasks effectively. They will certainly learn little. 


Dr Temple Grandin talks extensively about sensory difficulties in the first section of her lecture (view here). She has high-functioning autism, is an accomplished academic and is able to articulate her ideas with great clarity and eloquence.


Other topics/tags relevant to this article: non-verbal learning difficulties, low-latent inhibition, obsessive thought behaviours, complex tics, sensory defensiveness