Left visual neglect is a frequent and dramatic consequence of right hemisphere lesions. Diagnosis is important because behavioural and pharmacological treatments are available. Furthermore, neglect raises important issues concerning the brain mechanisms of consciousness, perception and attention. Recent behavioural findings and new techniques, such as transcranial magnetic stimulation, direct cortical and subcortical stimulation during brain surgery, and diffusion tensor imaging tractography, have provided evidence relevant to the debate concerning the functional mechanisms and the anatomical bases of neglect. Several component deficits appear to interact in producing different forms of neglect. Rather than lesions at single cortical levels, dysfunction of large-scale brain networks, often induced by white matter disconnection, may constitute the crucial antecedent of neglect signs.
