Abstract:
Working memory (WM) supports future behavior by retaining perceptual information obtained in the recent past. The present study tested the hypothesis that WM recodes sensory information in a format that better supports behavioral goals. We recorded EEG while participants performed color delayed-estimation tasks where the colorwheel for the response was either randomly rotated or held fixed across trials. Accordingly, observers had to remember the exact colors in the Rotation condition, whereas they could prepare for a response based on the fixed mapping between the colors and their corresponding locations on the colorwheel in the No-Rotation condition. Results showed that the color reports were faster and more precise in the No-Rotation condition even when exactly the same set of colors were tested in both conditions. To investigate how the color information was maintained in the brain, we decoded the color using a multivariate EEG classification method. The decoding was limited to the stimulus encoding period in the Rotation condition, whereas it continued to be significant during the maintenance period in the No-Rotation condition, indicating that the color information was actively maintained in the condition. Follow-up analyses suggested that the prolonged decoding was not merely driven by the covert shift of attention but rather by the recoding of sensory information into an action-oriented response format. Together, these results provide converging evidence that WM flexibly recodes sensory information depending on the specific task context to optimize subsequent behavioral performance.
摘要:
工作记忆(WM)通过保留最近获得的感知信息来支持未来的行为。本研究检验了WM以更好地支持行为目标的格式记录感官信息的假设。当参与者执行颜色延迟估计任务时,我们记录了EEG,其中响应的色轮在试验中随机旋转或固定。因此,观察者必须记住旋转条件下的确切颜色,而他们可以基于颜色之间的固定映射和在不旋转条件下它们在色轮上的相应位置来准备响应。结果表明,即使在两种条件下都测试了完全相同的一组颜色,在无旋转条件下,颜色报告也更快,更精确。为了研究颜色信息是如何在大脑中保持的,我们使用多变量脑电图分类方法解码颜色。解码被限制在旋转条件下的刺激编码周期,而在不旋转条件下的维护期间,它仍然很重要,表明颜色信息在条件下被积极地保持。后续分析表明,长时间的解码不仅是由注意力的秘密转移驱动的,而且是将感官信息重新编码为面向行动的响应格式。一起,这些结果提供了汇聚的证据,即WM根据特定的任务上下文灵活地编码感官信息,以优化随后的行为表现。