From corticocentrism to leucocentrism or both

Abstract

Chris Filley, the author of White Matter Dementia , is a neurologist with a special interest in the behavioural neurology of white matter. He introduced the term white matter dementia (WMD) in 1988 when evidence was accumulating for the importance of white matter in cognition, and uses it to cluster diseases that affect cerebral white matter leading to cognitive loss. He notes that a critical amount of damage must be present for clinical symptoms to develop, and emphasizes that WMD is a theoretical rather than diagnostic construct, conceived to draw attention to the importance of the white matter. White Matter Dementia provides a systematic overview of the published literature in the field and has been written to increase recognition of the cognitive symptoms seen in white matter disorders. For too long, this field has been ignored due to the dominant corticocentric perspective focusing on the role of the grey matter in cognition. It is clear that Filley is aware of the possible dangers of using only published data, such as the potential for selection bias leading to incorrect conclusions. He has done a fantastic job in giving a complete clinical overview of WMD, discussing not only the pathophysiology of several white matter diseases, but also the diagnostic issues, therapies and prognosis. Filley points out that consideration of evolution should lead one to imagine that white matter plays an important role in human behaviour. It has evolved far more than grey matter and makes up a greater proportion of the human brain than the brains of most other animals (white matter comprises 50% of total brain volume in humans compared with 14% in rodents, for example). Nonetheless the field has long been neglected in favour of the corticocentric view. Filley gives an interesting historical explanation for how this situation arose. The …