手近效应:研究内容、影响因素与神经机制

Hand Proximity Effect: Content, Influencing Factors and Neural Mechanisms

把手放在刺激旁边,会对知觉、记忆、语义和执行控制等认知加工产生影响,这类现象被称为手近效应。手近效应反映了身体与环境的互动对认知的塑造作用,为具身认知提供了新证据。本文从手近效应的内容,影响因素,及其认知、神经机制等方面对相关研究进行梳理。并从手近效应的神经机制,应用研究,以及动作意图和人际社会因素的调节作用等方面探讨当前手近效应还未解决的问题。

Recent studies have shown that human visual perception and attentional selection near the hands are substantially altered compared with the stimuli far from the hands. For example, visual stimuli near the hands are detected more quickly, discriminated more accurately and processed more thoroughly compared with those far from the hands. This cluster effect of hand-stimulus proximity on vision is termed the ＂hand proximity effect （HPE）＂. The research on the HPE has flourished in the past ten years. The purpose of this essay is to provide a systematic review of the existing body of literature. Research repeatedly found that placing hands near stimuli enhanced perceptual processing and spatial working memory in people with impaired perception and object-based perception. However, the results of hand-stimulus proximity＇s effect on executive control were inconsistent. Moreover, placing hands near the stimuli facilitated processing information relevant to grasp affordances. Thus, the affordance for specific actions moderated the HPE. The ownership of hand was another moderator. It was suggested that participants＇ own hand but not other＇s hand or fake hand near to the stimuli could affect visual processing. If the fake hand was somatically and visually similar to a real hand, however, putting fake hand near the stimuli could affect visual processing. After having cooperated to accomplish a task, other＇s hand near the stimuli could induce HPE as well. Consistent with the embodied cognition theory, the attention theories proposed action-based explanations of HPE： objects near the hands are candidates for action, thus they received enhanced processing. There were two attention theories for HPE. The attentional priority theory suggested that hand-stimulus proximity affected early visual processing, whereas the delayed disengagement theory suggested that hand-stimulus proximity affected later visual processing. However, a recent study that used event-related potentials found that the effect of hand-stimulus proximity on the visual processing ranged from early sensory processing to later cognitive processing. Two distinct theoretical accounts explained the neural mechanisms of HPE. The bimodal visuo-tactile neurons account suggested that stimuli in peri-hand space might activate the bimodal visuo-tactile neurons. Thus, the visual targets near the hand might be more salient than targets far from the hand because there were additional neural substrates representing the objects in peri-hand space. However, the trade-off of two visual pathways account suggested objects near the hand induced a bias toward the action-oriented magnocellular visual pathway. Conversely, objects far from the hand biased vision toward the perception-oriented parvocellular visual pathway. Future research should focus on the neural mechanisms, and the practical applications of the I-IPE. Moreover, the modulation of action- affordance, and the modulation of interpersonal and social factors on HPE may be promising in the future studies.