What is Unilateral neglect?



   One of the most striking disorders of cognition is unilateral neglect. Patients with this syndrome act as though whole regions of space contralateral to their lesions do not exist.  In early stages, patients may deny ownership of their contalateral limb and also neglect parts of their own body.  When dressing, they might not clothe the contralateral side and may fail to groom their hair or shave parts of their faces on that side.  


   Right hemisphere damage is a more common and more severe cause of unilateral neglect than left hemisphere damage (Chatterjee, 1995).  Damage causing left-sided neglect is usually centred on the inferior parietal lobule or superior temporal lobe of the right hemisphere.  Patients with such damage ignore events occurring on the left side of space (Bartolomeo & Chokron, 2002).  Patients may even fail to eat the food on the left side of their plate or bump into obstacles on their left side.  Below is a copied picture of a house drawn by a patient with left unilateral neglect. 

Copy of an outline drawing by a left neglect patient.


   The severity and frequency of attentional problems in neglect patients have been repeatedly underlined (Bartolomeo & Chokron, 2001).  Recent advances in the knowledge of the mechanisms of spatial attention in controls may help to characterize attentional problems in neglect patients.  In addition to a reduction in attention to the lateralized visual stimuli, neglect patients may also disregard contrlateral auditory stimuli, however, auditory neglect is not the particular focus of this project.  



What is Attention?