Attention Disorders After Right Brain Damage: Living in Halved Worlds PDF
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In a neurological ward, it is frequent to come upon patients who look at objects on their right side with intense interest, while paying no attention to what happens on their left. Left visual neglect is a dramatic but often overlooked consequence of right hemisphere damage, usually of vascular origin, but also resulting from other causes, such as neurodegenerative conditions. Patients do not eat from the left part of their dish, they bump their wheelchair into obstacles situated on their left side, and have a tendency to look at right-sided details as soon as a visual scene deploys, as if their attention were “magnetically” attracted to these details.
They are usually unaware of their defi cits (anosognosia) and often obstinately deny being hemiplegic. Patients with left brain damage may also show signs of contralesional, rightsided neglect, but much more rarely and usually in a less severe form. Diagnosis is important because neglect predicts poor functional outcome in stroke. Moreover, effective rehabilitation strategies are becoming available, and there are promising possibilities for pharmacological treatments. At least since the time of Paul Broca’s famous statement that “we speak with the left hemisphere,” the role of the right, “nonspeaking” hemisphere has been the object of questioning. After decades of limited interest in the then called “nondominant” or “minor” hemisphere, beginning in the second half of the twentieth century (Brain 1941; McFie et al. 1950), a wealth of research has burgeoned in subjects dealing with defi cits resulting from right hemisphere lesions, especially in the domain of visual neglect. Clinically, damage to the right hemisphere can lead to substantial levels of handicap and disability, which are probably even more severe and long-lasting than those occurring after lesions of similar volume and localization in the left hemisphere (Denes et al. 1982). For example, as Ennio De Renzi stated in his seminal book on spatial cognition (De Renzi 1982), “Unilateral spatial neglect after right hemispheric lesions has equal clinical and scientifi c importance to language disorders after left lesions.”