Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Institute of Brain and Behavior Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Elife. 2018 Nov 6;7:e38677. doi: 10.7554/eLife.38677.
Adaptive behavior requires the separation of current from future goals in working memory. We used fMRI of object-selective cortex to determine the representational (dis)similarities of memory representations serving current and prospective perceptual tasks. Participants remembered an object drawn from three possible categories as the target for one of two consecutive visual search tasks. A cue indicated whether the target object should be looked for first (currently relevant), second (prospectively relevant), or if it could be forgotten (irrelevant). Prior to the first search, representations of current, prospective and irrelevant objects were similar, with strongest decoding for current representations compared to prospective (Experiment 1) and irrelevant (Experiment 2). Remarkably, during the first search, prospective representations could also be decoded, but revealed anti-correlated voxel patterns compared to currently relevant representations of the same category. We propose that the brain separates current from prospective memories within the same neuronal ensembles through opposite representational patterns.
适应性行为需要在工作记忆中分离当前和未来目标。我们使用了物体选择性皮层的 fMRI，来确定服务于当前和预期感知任务的记忆表征的表示（不）相似性。参与者记住了从三个可能类别中选出的一个物体作为两个连续视觉搜索任务之一的目标。一个提示表明目标物体应该首先（当前相关）、其次（预期相关）还是可以被遗忘（不相关）。在第一次搜索之前，当前、预期和不相关物体的表示相似，与预期（实验 1）和不相关（实验 2）相比，当前表示的解码能力最强。值得注意的是，在第一次搜索期间，也可以对预期的表示进行解码，但与同一类别的当前相关表示相比，呈现出反相关的体素模式。我们提出，大脑通过相反的表示模式，在同一神经元集合中分离当前和预期的记忆。
