Kalm Kristjan, Norris Dennis
Cognition and Brain Sciences Unit, Medical Research Council, 15 Chaucer Road, Cambridge CB2 7EF, UK.
Cognition and Brain Sciences Unit, Medical Research Council, 15 Chaucer Road, Cambridge CB2 7EF, UK.
Neuroimage. 2017 Jul 15;155:138-146. doi: 10.1016/j.neuroimage.2017.04.047. Epub 2017 Apr 25.
Many complex tasks require people to bind individual events into a sequence that can be held in short term memory (STM). For this purpose information about the order of the individual events in the sequence needs to be maintained in an active and accessible form in STM over a period of few seconds. Here we investigated how the temporal order information is shared between the presentation and response phases of an STM task. We trained a classification algorithm on the fMRI activity patterns from the presentation phase of the STM task to predict the order of the items during the subsequent recognition phase. While voxels in a number of brain regions represented positional information during either presentation and recognition phases, only voxels in the lateral prefrontal cortex (PFC) and the anterior temporal lobe (ATL) represented position consistently across task phases. A shared positional code in the ATL might reflect verbal recoding of visual sequences to facilitate the maintenance of order information over several seconds.
许多复杂任务要求人们将单个事件绑定成一个可保存在短期记忆(STM)中的序列。为此,序列中各个事件顺序的信息需要在几秒钟的时间内以活跃且可访问的形式保存在STM中。在这里,我们研究了时间顺序信息是如何在STM任务的呈现和反应阶段之间共享的。我们根据STM任务呈现阶段的功能磁共振成像(fMRI)活动模式训练了一种分类算法,以预测后续识别阶段中项目的顺序。虽然在呈现和识别阶段,多个脑区的体素都代表位置信息,但只有外侧前额叶皮层(PFC)和颞叶前部(ATL)的体素在整个任务阶段都一致地代表位置。ATL中共享的位置编码可能反映了视觉序列的言语重新编码,以促进数秒内顺序信息的维持。