Data from: Binding space and time through action

Space and time are intimately coupled dimensions in the human brain. Several lines of evidence suggest that space and time are processed by a shared analogue magnitude system. It has been proposed that actions are instrumental in establishing this shared magnitude system. Here we provide evidence in support of this hypothesis, by showing that the interaction between space and time is enhanced when magnitude information is acquired through action. Participants observed increases or decreases in the height of a visual bar (spatial magnitude) while judging whether a simultaneously presented sequence of acoustic tones had accelerated or decelerated (temporal magnitude). In one condition (Action), participants directly controlled the changes in bar height with a hand grip device, whereas in the other (No Action), changes in bar height were externally controlled but matched the spatial/temporal profile of the Action condition. The sign of changes in bar height biased the perceived rate of the tone sequences, where increases in bar height produced apparent increases in tone rate. This effect was amplified when the visual bar was actively controlled in the Action condition, and the strength of the interaction was scaled by the magnitude of the action. Subsequent experiments ruled out that this was simply explained by attentional factors, and additionally showed that a monotonic mapping is also required between grip force and bar height in order to bias the perception of the tones. These data provide support for an instrumental role of action in interfacing spatial and temporal quantities in the brain.

时空在人类大脑中属于紧密耦合的维度。多项研究证据表明，空间与时间由同一套类比幅度系统（analogue magnitude system）进行加工。已有假说提出，动作在构建这一共享类比幅度系统中发挥着工具性作用。本研究通过实验为该假说提供了支撑证据：当通过动作获取幅度信息时，时空维度间的交互效应会显著增强。实验中，被试需观察视觉条形柱高度的升降（对应空间幅度），同时判断同步呈现的听觉音调序列是加速还是减速（对应时间幅度）。实验分为两种条件：动作组（Action）中，被试通过手持握力装置直接控制条形柱的高度变化；无动作组（No Action）中，条形柱高度变化由外部控制，但二者的时空特征完全匹配。条形柱高度变化的方向会使被试对音调序列速率的感知产生偏倚：条形柱升高时，被试会感知到音调速率变快。在被试主动控制视觉条形柱的动作组中，这一效应会被放大，且时空交互效应的强度随动作幅度的增大而递增。后续实验排除了该效应仅由注意力因素导致的可能，并进一步证实：要实现对音调感知的偏倚，握力与条形柱高度之间还需要存在单调映射关系。本研究结果证实，动作在人脑连接空间与时间数量表征的过程中发挥着工具性作用。