Yoxon Emma, Constable Merryn D, Welsh Timothy N
Faculty of Kinesiology & Physical Education, Centre for Motor Control, University of Toronto, Toronto, Ontario, Canada.
Department of Psychology, University of Toronto, Toronto, Ontario, Canada.
Atten Percept Psychophys. 2019 Oct;81(7):2410-2423. doi: 10.3758/s13414-019-01821-5.
Previous work has revealed that social cues, such as gaze and pointed fingers, can lead to a shift in the focus of another person's attention. Research investigating the mechanisms of these shifts of attention has typically employed detection or localization button-pressing tasks. Because in-depth analyses of the spatiotemporal characteristics of aiming movements can provide additional insights into the dynamics of the processing of stimuli, in the present study we used a reaching paradigm to further explore the processing of social cues. In Experiments 1 and 2, participants aimed to a left or right location after a nonpredictive eye gaze cue toward one of these target locations. Seven stimulus onset asynchronies (SOAs), from 100 to 2,400 ms, were used. Both the temporal (reaction time, RT) and spatial (initial movement angle, IMA) characteristics of the movements were analyzed. RTs were shorter for cued (gazed-at) than for uncued targets across most SOAs. There were, however, no statistical differences in IMAs between movements to cued and uncued targets, suggesting that action planning was not affected by the gaze cue. In Experiment 3, the social cue was a finger pointing to one of the two target locations. Finger-pointing cues generated significant cueing effects in both RTs and IMAs. Overall, these results indicate that eye gaze and finger-pointing social cues are processed differently. Perception-action coupling (i.e., a tight link between the response and the social cue that is presented) might play roles in both the generation of action and the deviation of trajectories toward cued and uncued targets.
先前的研究表明，诸如目光注视和手指指向等社交线索能够导致他人注意力焦点的转移。探究这些注意力转移机制的研究通常采用检测或定位按键任务。由于对瞄准动作的时空特征进行深入分析能够为刺激处理的动态过程提供更多见解，因此在本研究中，我们采用了伸手范式来进一步探索社交线索的处理过程。在实验1和实验2中，参与者在非预测性的目光注视线索指向其中一个目标位置后，朝着左侧或右侧位置伸手。使用了7种刺激起始异步时间（SOA），范围从100毫秒到2400毫秒。对动作的时间（反应时间，RT）和空间（初始运动角度，IMA）特征都进行了分析。在大多数SOA条件下，有线索提示（被注视）的目标的反应时间比无线索提示的目标短。然而，朝着有线索提示和无线索提示目标的动作在初始运动角度上没有统计学差异，这表明动作计划不受目光注视线索的影响。在实验3中，社交线索是指向两个目标位置之一的手指。手指指向线索在反应时间和初始运动角度上都产生了显著的线索提示效应。总体而言，这些结果表明目光注视和手指指向这两种社交线索的处理方式不同。感知 - 动作耦合（即反应与所呈现的社交线索之间的紧密联系）可能在动作的产生以及朝着有线索提示和无线索提示目标的轨迹偏差中都发挥作用。
