Eimer Martin, Forster Bettina, Fieger Anne, Harbich Stefanie
Department of Psychology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK.
Clin Neurophysiol. 2004 Mar;115(3):596-608. doi: 10.1016/j.clinph.2003.10.015.
Event-related brain potentials (ERPs) were measured to investigate spatial coordinate systems involved in the control of preparatory tactile-spatial orienting, and in subsequent attentional modulations of somatosensory processing.
On each trial, a visual precue directed attention to the left or right hand, where infrequent tactile targets had to be detected. Hands were positioned either close together or wide apart. ERPs were recorded in the cue-target interval and in response to attended and unattended tactile non-targets.
A frontal anterior directing attention negativity (ADAN) and a posterior late directing attention positivity (LDAP) were elicited in the cue-target interval contralateral to the direction of an attentional shift. The ADAN was unaffected by hand posture, but the LDAP was attenuated when hands were close together. N140 amplitudes were enhanced in response to tactile stimuli presented to the attended hand, and this effect was more pronounced when hands were wide apart.
ADAN and LDAP are linked to separable anterior and posterior attentional control systems, which use coordinate systems based on somatotopic and external space, respectively. Effects of spatial attention on somatosensory stimulus processing are affected by variations in body posture.
Our results demonstrate that representations of body locations in external space play a central role in the control of tactile attention.
测量事件相关脑电位（ERP），以研究参与准备性触觉空间定向控制以及随后体感加工的注意调制所涉及的空间坐标系。
在每次试验中，一个视觉预示线索将注意力引向左手或右手，在该手需要检测不频繁出现的触觉目标。双手的位置要么靠近要么分开。在预示线索 - 目标间隔期间以及对被注意和未被注意的触觉非目标的反应中记录ERP。
在注意转移方向对侧的预示线索 - 目标间隔期间引发了一个额部前向注意负波（ADAN）和一个后部晚期注意正波（LDAP）。ADAN不受手的姿势影响，但当双手靠近时LDAP减弱。对呈现给被注意手的触觉刺激，N140波幅增强，并且当双手分开时这种效应更明显。
ADAN和LDAP分别与可分离的前部和后部注意控制系统相关联，这两个系统分别使用基于躯体定位和外部空间的坐标系。空间注意对体感刺激加工的影响受身体姿势变化的影响。
我们的结果表明，外部空间中身体位置的表征在触觉注意控制中起核心作用。
