Làdavas E, Carletti M, Gori G
Dipartimento di Psicologia, Università di Bologna, Italy.
Neuropsychologia. 1994 Oct;32(10):1195-208. doi: 10.1016/0028-3932(94)90102-3.
The present study was aimed at testing internally and externally-controlled mechanisms of covert orienting in patients with visuo-spatial neglect. Internally-controlled orienting was tested by presenting central informative cues. Externally-controlled orienting was tested by presenting peripheral non-informative cues. We also tested for the presence of vertical neglect in patients with horizontal neglect, and tried to assess whether altitudinal neglect is an attentional deficit. Finally we examined whether altitudinal neglect manifests itself only in the visual field contralateral to the lesion or, as has been shown for horizontal neglect, whether it is also present in the ipsilesional visual field. The results showed that patients with neglect have a deficit of externally-controlled covert orienting in the visual field opposite to that of the lesion. Further, the impairment appeared to be more pronounced in the lower than in the upper visual field and to be mainly evident in the visual field contralateral to the lesion. The deficit could, however, be partially compensated for by the use of internally-controlled covert orienting. These findings seems to support the dual-mechanisms hypothesis which maintains that automatic and voluntary orienting are subserved by separate mechanisms possibly located in different parts of the brain.
本研究旨在测试视觉空间忽视患者隐蔽定向的内部和外部控制机制。通过呈现中央信息线索来测试内部控制定向。通过呈现外周非信息线索来测试外部控制定向。我们还测试了水平忽视患者中垂直忽视的存在情况，并试图评估高度忽视是否是一种注意力缺陷。最后，我们研究了高度忽视是否仅在病变对侧视野中表现出来，或者如水平忽视所示，它是否也存在于同侧视野中。结果表明，忽视患者在与病变相反的视野中存在外部控制隐蔽定向缺陷。此外，这种损害在下部视野比上部视野中似乎更明显，并且主要在病变对侧视野中明显。然而，通过使用内部控制隐蔽定向，这种缺陷可以得到部分补偿。这些发现似乎支持双机制假说，该假说认为自动和自愿定向由可能位于大脑不同部位的不同机制提供支持。
