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Neglect can be ego-centered or object-centered depending on the reference frames for "left" and "right", of either the body or an object. It has been suggested that object-centered neglect is not a general phenomenon but is limited to words because only they have a true canonical representation. Here, we examined whether object-centered neglect could be observed for non-verbal material by creating, after repeated exposure, a canonical representation of a nonsense figure. Fourteen neglect patients repeatedly bisected a series of asymmetrical nonsense drawings containing two different shapes at their right and left end-points (canonical trials). In the critical trials, which were the last three in the series, the position of the two shapes was mirror-reversed. Afterwards, neglect patients were asked to draw the stimulus, which provided a further measure of whether a canonical representation of the object has been built by the patients. All the patients made rightward errors with the canonical stimuli. With mirror-reversed stimuli, the bisection errors were reversed to the contralesional side in one patient, returned to zero in one patient and significantly decreased in three patients. In addition, 10 patients reliably drew the canonical stimulus at the end of the series of trials, providing an indication that they built up a canonical representation of the stimulus. The present data provide evidence that object-centered neglect is a phenomenon that is not limited to words. The nature of a stimulus, verbal or non-verbal, is not critical for observing object-centered neglect. What is critical is the way in which material is represented by the patients.

Perseveration in target cancellation tasks and in drawing by copy and from memory was investigated in 21 right-brain-damaged patients, seven with no evidence of left visuo-spatial neglect, and 14 with neglect. Eight such neglect patients showed perseveration in both cancellation and drawing tasks, although no correlation was found with the severity of neglect. Patients with perseveration were not disproportionately impaired in tasks assessing executive (fluency, Stroop colour-word interference, and Weigl's sorting test), and visuo-spatial short-term memory function. In the context of a two-component hypothesis, graphic perseveration (the first component) is a specific disorder that manifests in a variety of tasks, particularly those requiring serial graphic production. Unilateral spatial neglect (the second component) may trigger and facilitate the production of perseveration errors, with a contra-ipsilateral gradient of increasing severity.

A case of unilateral visual agnosia for all types of stimuli limited to the left visual hemifield and associated with a right occipital temporal vascular lesion is reported. Questions raised by this case of hemiagnosia as compared to previous ones are discussed.