Spatial representation of time during motor preparatory information processing in humans

计划中的研究旨在阐明人类感觉运动转换的特征。最近的研究结果表明，刺激的认知心理表征，如数字（从1到9）、听觉音高（从低到高）和字母表中的字母（从A到Z）具有空间特征，这影响了反应速度。关于数字和空间信息之间相互作用的证据，例如，较小的数字（如1和2）与右侧反应相比，更有利于左侧手动反应，而较大的数字（如8和9）与左侧反应相比，更有利于右侧反应。这表明“心理数轴”的存在，即数字大小的空间表征，这种表征与空间中的运动准备相互作用。近年来，神经心理学研究和脑成像研究表明，下顶叶反映了在感觉运动转换中对空间、时间和数量信息的共同需求，表明下顶叶是一个广义的动作幅度系统。因此，我们可以假设，在运动准备过程中，时间信息（如从早到晚）会与空间信息相互作用。基于这一假设，我计划进行实验，以阐明感觉运动转化中时空关联的特征。我进行的初步实验显示了有希望的结果：时间信息与行动中的空间信息相互作用。这一新颖的发现促使人们进一步研究与感觉运动转换相关的“精神时间线”。计划中的研究包括对正常受试者和表现出单侧忽视的脑损伤患者的调查。

The planned research aims to clarify the characteristics of sensorimotor transformations in humans. Recent findings have shown that cognitive mental representations of stimuli, such as numerals (from 1 to 9), auditory pitch (from low to high), and letters of the alphabet (from A to Z) have spatial characteristics, and that this influences speed of responses. With respect to the evidence of an interaction between numerals and spatial information, for example, smaller numbers (e.g., 1 & 2) facilitate left-side manual responses compared to right-side responses, whereas larger numbers (e.g., 8 & 9) facilitate right-side responses compared to left-side responses. This suggests the existence of the ‘mental number line,’ i.e., spatial representations of the magnitude of numbers, and such a representation interacts with motor preparation in space. Recently, neuropsychological studies and brain imaging studies revealed that the inferior parietal lobule (IPL) reflects the common need for space, time, and quantity information to be used in sensorimotor transformations, suggesting that the IPL is a generalized magnitude system for action. Therefore, it can be hypothesized that temporal information (e.g., from early to late) would interact with spatial information during motor preparation. Based on this hypothesis, I am planning to run experiments in order to clarify the characteristics of spatial-temporal associations in sensorimotor transformation. Preliminary experiments which I have conducted showed promising results: temporal information interacts with spatial information in action. This novel finding invites further investigations on the ‘mental time line’ in relation to the sensorimotor transformation. The planned research includes investigations in both normal subjects and brain injured patients who show unilateral neglect.