Editorial
As more is learned about how the healthy brain works, so it becomes tempting to push out the boundaries of what, within the spectrum of human behaviour, can nicely be reduced to ‘the integrative action of the nervous system’, leaving that which—for the while—must remain mysterious. Perhaps the most tantalising yet least tractable target for analysis-by-neuroscience is consciousness. Some resent this systematic invasion of privacy as the ruthless march of ‘neuro-scrutiny’ reduces every aspect of human culture and social structure—goodness and badness, law and order, economics and ethics—to mere collisions of the ‘soups and the sparks’ (see Brain 2007: 130; 299–302). In this issue we publish two book essays that explore these issues in some detail. Daniel Dennett is Professor of Philosophy at Tufts University, USA. His writings espouse the power of evolution to explain self, consciousness and free will, and—most recently, in Breaking the spell—he challenges those with faith to evaluate God and religion using scientific methodology. Professor Dennett predicts, in The Times (London) of January 1st 2007, the disappearance of religious fervour as facts gradually erode the possibility of belief over the next 20 years. In his review of Seeing red: a study in consciousness, Daniel Dennett considers the position proposed by the neuroscientist and philosopher, Nicholas Humphrey, in the sequel to his A history of mind (1992), books that straddle an era in which writing on consciousness changed from the occasional mild act of eccentricity to a industry embraced by mainstream philosophy and neuroscience, and in which everyone waits for the ‘eureka’ moment of illumination (page 592). Does Humphrey provide it? Dennett argues that it is for philosophers to formulate the right questions and for scientists then to provide meaningful data. This division of labour may prove unpalatable for both communities, each seeking to reveal all. When Nicholas Humphrey and Larry Weiskrantz (former deputy editor of Brain) first described blindsight, it followed that individuals can sense (see) without perceiving, and vice versa. This realisation took Humphrey away from the limitations of a developmental relationship between sensation and perception—here, ‘seeing red’—towards the formulation that we only sense things that ‘matter to us’; seeing red teaches something about ourselves since it induces a state of ‘redding’. This awareness is ‘self’, from which follows the notion of ‘other’ and, together with its deliberate and crafty yet intrinsically creative shroud of mystery, the state of ‘consciousness’ thereby evolves. Generally, and despite having many pet theories of his own, Professor Dennett approves of the ‘somewhat lawless’ approach as Nicholas Humphrey cherry-picks his way through a wide variety of sources, and nimbly steers clear of inconvenient obstacles, in assembling ‘his half-baked pudding of what-ifs’ on the neuroscience and nature of consciousness.On page 585, Andrew Scull takes up the theme of evolution, social behaviour and the brain in reviewing Law and the brain (edited by Semir Zeki and Oliver Goodenough), and Brain and culture: neurobiology, ideology and social change (by Bruce Wexler). As psychiatrist, medical historian and sociologist, now at the University of California, San Diego, Professor Scull has written on psychiatry in Britain and the USA in the 18–20th centuries, medical specialization and therapeutics, and somatic therapies in Anglo-American psychiatry including, most recently, Madhouse: A tragic tale of megalomania and modern medicine (2006). He paints a frightening picture of the expectation that brain science is set to inform and govern all aspects of the law. And he is persuasively dismissive of the insights that functional MRI and the like provide in understanding a system sculpted and honed by centuries of social evolution, and one that does not need the heavy-boots of psychologists and neuroscientists to guide its procedures and practices. He invites our readers to ‘awake from the dream of certitude’ proposed by tomorrow's brainy-lawyers; to re-read those who have visited this territory many times before; and to take a few nasty lessons from history of what goes wrong if materialism, and the wish to manipulate it, are allowed precedence over a loftier and more mysterious view of the human condition. Andrew Scull does not sign up to anything much in this ‘farrago of nonsense, unsupported speculation, breathtaking chutzpah and massive speculation’ (and worse) that has us as mere puppets helplessly acting out the imprinted neurodeterminism on offer in Law and the brain. For him, much better is Brain and culture in which the biological and social interact cooperatively. Such a relationship sits more comfortably with current ideas on the social nature of human consciousness, and benefits that accrue to the individual as member of a society aquiring novel and successful behaviours from the learning, plasticity and adaptation that, self-evidently, are the stuff of responsive and highly evolved nervous systems. But in his treatment of neurobiology and wars, crusades, genocide and inquisitions, Andrew Scull does not acquit Bruce Wexler entirely from the accusation of seduction by the siren songs of biological reductionism.
The present issue includes two reviews and four original papers on epilepsy: of these, four deal with surgical treatment. José Téllez-Zenteno and a team from Calgary (Canada), St Louis (USA) and Mexico City (Mexico) review 15 years of publications, from all sources, on the long-term outcome (
5 years) of epilepsy surgery, not necessarily involving tissue resection, to show that, both for the most common indication (drug resistant temporal lobe epilepsy) and in all other contexts, drug treatments subsequently are redundant or much simplified in two-thirds, especially children, and these improvements accumulate over time (page 334): secondary effects of reduced drug therapy include lower mortality, less psychosocial morbidity, and improved cognitive function. More specifically, Lara Jeha and colleagues from the Cleveland Clinic, Ohio (USA) evaluate patients undergoing frontal lobe epilepsy surgery over an 8 year period of follow-up (page 574); inevitably, the initial seizure-free rate (56%) subsequently drops (to 30%); a less favourable outlook is seen in those with normal pre-operative MR imaging, lesions outside the frontal regions, widespread electroencephalographic abnormalities, a stormy post-operative course, and less than comprehensive surgical excision of any defined abnormality. These features account for a difference in favourable outcome varying between >50% and <15%. On this same topic, Lino Nobili and investigators from Milan (Italy) report an excellent surgical results in the subset of cases whose frontal epilepsy occurs more or less exclusively at night, if pre-operative assessment of the area for resection is meticulous and the histological sample reveals focal cortical dysplasia (page 561). Anita Vinton and colleagues from Melbourne (Australia) show that a poor surgical result following temporal lobectomy correlates with the extent to which the resection fails to remove an area of hypometabolism revealed by pre-operative fluordeoxyglucose positron emission tomography (FDG-PET), irrespective of whether the surgical sample shows hippocampal sclerosis, or how much brain tissue was originally hypometabolic (page 548).
Amongst three papers on the special senses, Pamela Butler and investigators from institutions in Orangeberg and New York, NY (USA) exploit the differential sensitivity of sub-cortical pathways for vision to demonstrate dysfunction of the magnocellular system that alters the activation of structures within the dorsal and ventral streams, in schizophrenics; they suggest that—apart from putting right the record on the locus of abnormal processing—this feature can be applied to a more general theory of disorganization for cognitive processing in schizophrenia (page 471). Giorgia Committeri and a team from Chieti, Rome and Lecce (Italy) compare the anatomy of lesions responsible for neglect, detected by MRI and manipulated in detail for reliable statistical comparison, to show that awareness of extrapersonal space depends on right frontal and superior temporal circuits – allocating exogenous space and re-orientating attention—whereas person-specific space uses a right inferior parietal system that ordinarily inter-connects the coding of proprioceptive and sensory inputs with areas subserving more abstract spatial representations (page 431).
The six papers on aspects of neurogenetics include work from Roger Low and colleagues in Newcastle-upon-Tyne, Bristol, Aberdeen and Gloucester (UK), Turku and Helsinki (Finland), and Göteborg, Uppsala and Stockholm (Sweden) showing that the two original families described from Sweden and England in 1977, since assumed to have the same disorder and thought likely to be ‘CADASIL’, are in fact different (page 357). The English family has a mutation of Notch3; the Swedish pedigree does not. Having spotted that the genotypes are not the same, more careful scrutiny now also reveals laboratory distinctions making it inappropriate to consider the hereditary small vessel diseases, including CADASIL, as a single disorder. Jonathan Jarry and colleagues from the Universities of Montreal and Laval, Québec, and Sherbrooke (Canada) map a novel autosomal recessive muscular dystrophy, mimicking ‘quadriceps myopathy’ but with initial involvement of the hamstrings and adductors, in 14 French-Canadians from 8 ‘different’ families, to a 3.3 cM interval at 11p13–p12 (page 368): the phenotype evolves into a typical ‘limb-girdle muscular dystrophy’. This is a term that every post-World War II textbook of neurology lists as one major category of inherited muscle disease, even if the advent of molecular classifications that implicate several responsible genetic mutations has eroded that phenotype. The concept of ‘limb–girdle muscular dystrophy’ emerged from a careful and critical review of the literature and of personal cases by John Walton and Professor F.J. Nattrass in the early 1950s. In From the Archives, we review ‘On the classification, natural history and treatment of the myopathies’ by John N. Walton and F.J. Nattrass (Brain 1954: 77; 169–231).
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