Autism: A world changing too fast for a mis-wired brain?

Disorders in verbal and emotional communication and imitation, social reciprocity and higher order cognition observed in individuals with autism spectrum disorders (ASD) are presented here as phenotypic expressions of temporo-spatial processing disorders (TSPDs). TSPDs include various degrees of disability in (i) processing multi-sensory dynamic stimuli online, (ii) associating them into meaningful and coherent patterns and (iii) producing real-time sensory-motor adjustments and motor outputs. In line with this theory, we found that slowing down the speed of facial and vocal events enhanced imitative, verbal and cognitive abilities in some ASD children, particularly those with low functioning autism. We then argue that TSPDs may result from Multi-system Brain Disconnectivity-Dissynchrony (MBD), defined as an increase or decrease in functional connectivity and neuronal synchronization within/between multiple neurofunctional territories and pathways. Recent functional magnetic resonance imaging (fMRI) and electrophysiological studies supporting MBD are outlined. Finally, we review the suspected underlying neurobiological mechanisms of MBD as evidenced in neuroimaging, genetic, environmental and epigenetic studies. Overall, our TSPD/MBD approach to ASD may open new promising avenues for a better understanding of neuro-physio-psychopathology of ASD and clinical rehabilitation of people affected by these syndromes. (C) 2009 Elsevier Ltd. All rights reserved.