Colman Hayley A, Remington Roger W, Kritikos Ada
School of Psychology, University of Queensland, Brisbane, Queensland, Australia.
Department of Psychology, University of Minnesota, Minneapolis, Minnesota, United States of America.
PLoS One. 2017 Jan 26;12(1):e0170542. doi: 10.1371/journal.pone.0170542. eCollection 2017.
We examined how factors related to the internal representation of the hands (handedness and grasping affordances) influence the distribution of visuospatial attention near the body. Left and right handed participants completed a covert visual cueing task, discriminating between two target shapes. In Experiment 1, participants responded with either their dominant or non-dominant hand. In Experiment 2, the non-responding hand was positioned below one of two target placeholders, aligned with the shoulder. In Experiment 3 the near-monitor hand was positioned under the placeholder in the opposite region of hemispace, crossed over the body midline. For Experiments 2 & 3, in blocked trials the palmar and back-of hand surfaces were directed towards the target placeholder such that targets appeared towards either the graspable or non-graspable space of the hand respectively. In Experiment 2, both left and right handers displayed larger accuracy cueing effects for targets near versus distant from the graspable space of the right hand. Right handers also displayed larger response time cueing effects for objects near the graspable versus non-graspable region of their dominant hand but not for their non-dominant hands. These effects were not evident for left-handers. In Experiment 3, for right handers, accuracy biases for near hand targets were still evident when the hand was crossed over the body midline, and reflected hand proximity but not functional orientation biases. These findings suggest that biased visuospatial attention enhances object identity discrimination near hands and that these effects are particularly enhanced for right-handers.
我们研究了与手部内部表征相关的因素（利手和抓握能力）如何影响身体附近视觉空间注意力的分布。左利手和右利手参与者完成了一项隐蔽视觉线索任务，区分两种目标形状。在实验1中，参与者用优势手或非优势手做出反应。在实验2中，不做出反应的手放在两个目标占位符之一下方，与肩部对齐。在实验3中，靠近显示器的手放在半空间相反区域的占位符下方，越过身体中线。对于实验2和3，在分块试验中，手掌和手背表面指向目标占位符，使得目标分别出现在手可抓握或不可抓握的空间方向。在实验2中，左利手和右利手对于靠近或远离右手可抓握空间的目标都表现出更大的准确性线索效应。右利手对于靠近其优势手可抓握区域而非不可抓握区域的物体也表现出更大的反应时间线索效应，但对于非优势手则没有。这些效应在左利手者中不明显。在实验3中，对于右利手者，当手越过身体中线时，靠近手部目标的准确性偏差仍然明显，并且反映了手部接近程度而非功能方向偏差。这些发现表明，有偏差的视觉空间注意力增强了手部附近物体身份的辨别，并且这些效应在右利手者中尤其增强。
