Eric Courchesne and colleagues at UC San Diego published a paper earlier this year on “Disrupted neural synchronization in toddlers with autism“. A number of previous studies have presented evidence for a deficit in long range, but increased short range, connections in autism. Normally, various functionally connected parts of the brain are electrically synchronized such that neural activity occurs simultaneously in these areas. Such synchrony is not as obvious in autism. In the very large Courchesne study, sleeping toddlers who were diagnosed with autism (or who would later be diagnosed with autism) displayed weak synchrony between the the parts of the brain on each side that are responsible for language. Moreover, the level of this deficit in synchrony correlated with deficits in verbal ability! Deficits in synchrony have also been reported in adolescents and adults with autism.
Interestingly, the mouse model of an environmental risk factor for autism described in Chap. 6 of my book also displays a feature of this type. As shown by David Bilkey and colleagues at the University of Otago in New Zealand, the offspring of mothers whose immune systems were activated during pregnancy exhibit reduced synchrony between the hippocampus and prefrontal cortex. These authors make the point that such a deficit is also seen in schizophrenia. This is relevant for this mouse model because maternal infection is a risk factor for both schizophrenia and autism, as discussed in Chap. 5.