Làdavas E, Berti A, Ruozzi E, Barboni F
Dipartimento di Psicologia Generale, Università di Padova, Italy.
Exp Brain Res. 1997 Oct;116(3):493-500. doi: 10.1007/pl00005777.
A previous study on neglect suggested that at least two hand parameters are crucial in producing an amelioration of neglect: the hand (left or right) and the spatial position of the hand (left or right). The improvement observed in perceiving left targets when the left hand acts in the left space can be due either to proprioceptive or to visual cuing. The stimulated left hand located in the left space may act as a powerful visual cue for the enhancement of the left visuo-spatial representation, in the same way as any other visual stimulus presented in the periphery of the visual field. Alternatively, it may be that the perceived hand location (due to the activation of the proprioceptive system) acts as an attentional field able to enhance the representation of the left space. In order to disentangle these two hypotheses, in the present study a naming task was executed by a group of neglect patients and by a control group. The subjects had to name all the objects depicted on a sheet of paper which were reflected on a mirror that inverted right and left space. While doing the naming performance, the subjects passively moved either the right or the left hand, in the left or right space. Stimuli and hand were reflected in the mirror that inverted right and left space and direct view of the stimuli and of the stimulated hand was prevented by a board. The results show that patients were more accurate at naming stimuli reflected in the left side of the mirror when the left hand was located and moved on the left side. In this condition, however, the left hand was seen in the right side of the mirror. It is therefore clear that the better performance was not due to visuo-spatial cuing but to a proprioceptive cuing effect. The results are discussed in terms of the relevance of personal and peripersonal spatial activation in the modulation of extrapersonal visual neglect. The coactivation of different spatial representations seems to be very influential on stimulus coding, thus confirming that spatial awareness is strictly related to the joint activity of multiple brain maps.
先前一项关于忽视症的研究表明，至少有两个手部参数对于改善忽视症状至关重要：手（左手或右手）以及手的空间位置（左侧或右侧）。当左手在左侧空间活动时，在感知左侧目标方面观察到的改善可能是由于本体感觉或视觉提示。位于左侧空间的受刺激左手可能作为一种强大的视觉提示，用于增强左侧视觉空间表征，就像视野周边呈现的任何其他视觉刺激一样。或者，可能是所感知的手部位置（由于本体感觉系统的激活）充当了一个注意力场，能够增强左侧空间的表征。为了区分这两种假设，在本研究中，一组忽视症患者和一个对照组执行了一项命名任务。受试者必须说出一张纸上描绘的所有物体的名称，这些物体在一面左右空间颠倒的镜子中反射呈现。在进行命名任务时，受试者在左侧或右侧空间被动地移动右手或左手。刺激物和手在左右空间颠倒的镜子中反射，并且一块板子阻止了受试者直接看到刺激物和受刺激的手。结果表明，当左手位于镜子左侧并在左侧移动时，患者对镜子左侧反射的刺激物进行命名时更准确。然而在这种情况下，左手在镜子右侧被看到。因此很明显更好的表现不是由于视觉空间提示，而是由于本体感觉提示效应。根据个人和周边空间激活在调节个人空间外视觉忽视中的相关性对结果进行了讨论。不同空间表征的共同激活似乎对刺激编码有很大影响，从而证实空间意识与多个脑图谱的联合活动密切相关。
