title: Mislocalization of tactile stimuli applied to the trunk in spatial neglect.
abstract: BACKGROUND
  In patients with spatial neglect, body perception and representation are impaired - especially the projection of the anterior body midline in anterior space (the subjective "straight ahead"). However, data on more lateral body parts and the posterior body surface are scarce. We explored deviations of the perception of different body points located to the left or right of the midline and on the anterior and posterior body surfaces, and their lesion correlates in right hemisphere stroke patients.
  
  
  METHODS
  Nine patients with neglect (diagnosed with paper and pencil and behavioural tests) were compared with six non-neglect patients and 13 healthy controls. The subjects had to use a mannequin to designate the body location that had been stimulated by a blunt pencil tip. Four horizontally arranged series of locations were traced on the anterior and posterior body surfaces at shoulder and navel levels. Each horizontal series comprised five equidistant test points, from left to right and corresponded to eleven labelled points on the mannequin. Patient errors were confronted to their anatomic lesions (MRI).
  
  
  RESULTS
  We found a significant (p ≤ .05) rightward deviation of the left-side points and midpoint and a significant leftward deviation of the right-most point in neglect patients. Non-neglect patients and control subjects designated all the test points accurately. The body side (anterior or posterior) and the line (shoulder or navel) did not influence performance. Controls showed a definite reduction in variability for the midline points, which disappeared in neglect patients who showed a severe global increase of this variability. Errors depended on lesions centred on the intraparietal sulcus.
  
  
  CONCLUSIONS
  These observations were compatible with a complex bias in body perception-representation extending to various lateral body points, with a left to right gradient. The right parietal cortex likely participates in processing such information.
authors: EA 1026, University of Lille Nord de la France, Lille, France; Neurological Rehabilitation Unit, CHRU, Lille, France. Electronic address: marc.rousseaux@chru-lille.fr.
authors: Marc
authors: M
authors: Rousseaux
authors: Angéline
authors: A
authors: Sauer
authors: Arnaud
authors: A
authors: Saj
authors: Thérèse
authors: T
authors: Bernati
authors: Jacques
authors: J
authors: Honoré
mesh_terms: D000328:Adult; D000368:Aged; D001828:Body Image; D003627:Data Interpretation, Statistical; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008348:Manikins; D008875:Middle Aged; D010468:Perceptual Disorders / Q000209:etiology / Q000523:psychology*; D011597:Psychomotor Performance / Q000502:physiology; D012649:Self Concept; D012867:Skin / Q000294:innervation; D020521:Stroke / Q000150:complications / Q000523:psychology; D013909:Thorax; D014110:Touch / Q000502:physiology*
keywords: Body perception; Body schema; Spatial neglect; Stroke