Left of what? The role of egocentric coordinates in neglect.

OBJECTIVES: Egocentric coordinate systems centred on the trunk, head, and gaze have been investigated in a patient who displays severe extrapersonal neglect and in five control subjects. METHODS: The subjects were tested with a blind tactile exploration task in five different experimental conditions in which the role of the three distinct frames of reference was individually controlled. RESULTS: Only the trunk centred coordinates significantly influenced the performance of the patient, therefore proving of paramount importance in determining the boundaries of the neglected field. Similar results emerged from a single word reading task, in which the patient's performance improved when the stimuli were presented to the right of his body's midline. CONCLUSION: These findings point to the importance of the body centred coordinate system in determining the area of extrapersonal spatial neglect.

[Cervical pain and proprioceptive sensitivity]. / Cervicalgie e sensibilità propriocettiva.

With the intent of estimating the proprioceptive sensitivity of the cervical rachis, the Authors subjected 17 healthy volunteers and 20 patients suffering from various cervical disorders to a clinical head positioning test, which was previously experimented upon by several french Authors was modified under certain aspects by our equipe. The test, consists in flexion and extension of the head after maximal rotations to the left and right, then repositioning the head at the starting point "0" which corresponds to the crossing point of two orthogonal axis of a target. The positions are marked on the target by a laser beam situated on the helmet worn by the subject undergoing testing. The results obtained corresponding to the errors committed regarding point "0", permit us to confirm the reliability of the test and significant definitions between the control group and the patients suffering from cervical disorders.

Ignoring left and far: an investigation of tactile neglect.

The aims of this paper were to identify patients with tactile neglect, to corroborate its independence from visual neglect, to ascertain its presence along the radial dimension of space and to detect a gradient of performance, as recently reported for visual neglect. To this end eight patients with vascular right cerebral lesions and 28 healthy controls have been tested with a modified version of the tactile maze test of De Renzi et al. [Cortex, vol. 6, pp. 191-203, 1970] and a seven-test clinical battery to detect the presence of visual USN. Four patients presenting tactile USN were selected: two showed left tactile neglect while the other two showed tactile neglect for far space. The distribution of omissions showed a clear spatial gradient. Since our patients were blindfolded, neglect behaviour in the tactile domain cannot be attributed to the attractive power of visual information. However, 25% of the normal subjects were also significantly faster in the 'near' space pointing towards the possibility that neglect for 'far' space can reflect the exaggeration of a normal asymmetry.