The Intense World Syndrome – an alternative hypothesis for autism
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Switzerland
Autism is a devastating neurodevelopmental disorder with a polygenetic predisposition that seems to be triggered by multiple environmental factors during embryonic and/or early postnatal life. While significant advances have been made in identifying the neuronal structures and cells affected, a unifying theory that could explain the manifold autistic symptoms has still not emerged. Based on recent synaptic, cellular, molecular, microcircuit, and behavioral results obtained with the valproic acid (VPA) rat model of autism, we propose here a unifying hypothesis where the core pathology of the autistic brain is hyper-reactivity and hyper-plasticity of local neuronal circuits. Such excessive neuronal processing in circumscribed circuits is suggested to lead to hyper-perception, hyper-attention, and hyper-memory, which may lie at the heart of most autistic symptoms. In this view, the autistic spectrum are disorders of hyper-functionality, which turns debilitating, as opposed to disorders of hypo-functionality, as is often assumed. We discuss how excessive neuronal processing may render the world painfully intense when the neocortex is affected and even aversive when the amygdala is affected, leading to social and environmental withdrawal. Excessive neuronal learning is also hypothesized to rapidly lock down the individual into a small repertoire of secure behavioral routines that are obsessively repeated. We further discuss the key autistic neuropathologies and several of the main theories of autism and re-interpret them in the light of the hypothesized Intense World Syndrome.
autism, microcircuit, connectivity, plasticity, neocortex, amygdala, valproic acid
Henry Markram, Tania Rinaldi and Kamila Markram (2007). The Intense World Syndrome – an alternative hypothesis for autism. Front. Neurosci. 1: 1. 77-96. doi: 10.3389/neuro.01/1.1.006.2007
Received: 15 August 2007; Paper pending published: 01 September 2007;
Accepted: 01 September 2007;
Published online: 15 October 2007.
Idan Segev, Hebrew University, Israel
Joseph LeDoux, New York University, USA
Jacqueline N. Crawley, National Institute of Mental Health, USA
© 2007 Markram, Rinaldi and Markram. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
Dr. Kamila Markram, Brain Mind Institute, EPFL SV BMI LNEP, Building AAB - Office 201 - Station 15, 1015 Lausanne, Switzerland. Tel.: +41 21 6931642; fax: +41 21 6939635. e-mail: firstname.lastname@example.org