ABSTRACT
To gain an understanding of how neurobiological structures affect autistic behaviours, it is first important to look briefly at the neurobiology of normal development, at the brain's composition, communication, and growth. The American neuroscientist Paul Maclean put forward the evolutionary model for understanding brain development by dividing the human brain into three distinct regions, which initially he named reptilian, mammalian, and human/rational regions. The brain is composed of grey matter and white matter. Grey matter is mainly found in the cortex and is densely packed with connected neurons responsible for information processing. While strong connections have yet to be made to the rational brain, the mammalian brain is in control in infants. Behaviours lead to enriched neural networks, neural activity, and a procedural memory, which is later accessed by the infant. Procedural memory is linked to the interpersonal know-how of relationships and social relating, both of which are located in the right hemisphere of the brain.
