Neuroscience for Counsellors by Wilson Rachal Zara;

Author:Wilson, Rachal Zara; [Rachal Zara Wilson]
Language: eng
Format: epub
ISBN: 9780857008947
Publisher: Jessica Kingsley Publishers
Published: 2014-03-05T00:00:00+00:00

Autisic spectrum disorders, including Aspergers

What do we know?

Autistic spectrum disorders (ASD) range from Asperger’s syndrome at the milder end of the continuum, to autism at the more severe (Belmonte et al., 2004; Tantum, 1988). ASD is defined by dysfunctions which result in impaired social interaction and communication, obsessive interests and repetitive behaviours. Speech is often affected in those at the more extreme end of the ASD continuum, and other motor deficits such as physical clumsiness and dyspraxia may be present. Those with ASD often find it difficult to execute or interpret body language and facial expressions. The ability to empathize with and understand the motivations of others is poor. They also tend to be rigid in their logic and understanding, and to comprehend language in a literal way (Belmonte et al., 2004; Mundy and Neal, 2000). Baranek (2002) also notes auditory processing problems (not a hearing difficulty, but problems with the brain’s interpretation of the sounds heard by the ear) in most children and teenagers with ASD, as well as compulsive, repetitive actions.

Neurologically, one of the differences between the brains of those with ASD and the brains of those who do not, appears to be an abnormally high level of localized neural connectivity within discrete regions of the brain, which develops in tandem with an abnormally low connectivity between the differing regions. The cerebellum is particularly implicated in this failure of connectivity (Belmonte et al., 2004). This may account for the effect of processing too much sensory information and the inability to filter out what is relevant and what is not. Those with ASD often have accompanying sensory sensitivities and/or sensory obsessions from a young age (Baranek, 2002; Belmonte et al., 2004).

Low regional connectivity of the brain is probably the reason why those with ASD can experience an inability to integrate different functions of the brain, for instance, the function of language processing with the motor function of the tongue (Belmonte et al., 2004). Physical clumsiness of fine motor muscles in the hands and fingers appears to stem from poor neural pathway preparation through initial stages of the neural connectivity rather than an inability to physically execute the required movements (Baranek, 2002). High local neural connectivity combined with weak regional connectivity potentially incurs a higher load at later processing stages of perceptual integration, and higher order brain functions such as learning and memory (Belmonte et al., 2004) (like a traffic jam on narrow, congested roads). There is some similarity in EEG measured brain activation between siblings who have ASD and those who don’t, suggesting a genetic predisposition to low activity and integration between different regions of the brain (Belmonte et al., 2004).

In those affected by ASD, there is a documented reduction in the number of cerebellar Purkinje cells in the cerebellum, and incomplete development of the cerebellar vermis (a narrow structure between the two hemispheres of the cerebellum) and the cerebellar hemispheres. (Purkinje cells are large complex neurons typically involved in receiving synaptic input and with outputs relating to motor function, learning and attention, and cognition.

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