Zhu Jiating, Tian Karen J, Carrasco Marisa, Denison Rachel N
Department of Psychological and Brain Sciences, Boston University, 64 Cummington Mall, Boston, MA 02215, USA.
Department of Psychology, New York University, 6 Washington Place, New York, NY 10003, USA.
PNAS Nexus. 2024 Nov 29;3(12):pgae535. doi: 10.1093/pnasnexus/pgae535. eCollection 2024 Dec.
The human brain faces significant constraints in its ability to process every item in a sequence of stimuli. Voluntary temporal attention can selectively prioritize a task-relevant item over its temporal competitors to alleviate these constraints. However, it remains unclear when and where in the brain selective temporal attention modulates the visual representation of a prioritized item. Here, we manipulated temporal attention to successive stimuli in a two-target temporal cueing task, while controlling for temporal expectation with fully predictable stimulus timing. We used magnetoencephalography and time-resolved decoding to track the spatiotemporal evolution of stimulus representations in human observers. We found that temporal attention enhanced the representation of the first target around 250 ms after target onset, in a contiguous region spanning left frontal cortex and cingulate cortex. The results indicate that voluntary temporal attention recruits cortical regions beyond the ventral stream at an intermediate processing stage to amplify the representation of a target stimulus. This routing of stimulus information to anterior brain regions may provide protection from interference in visual cortex by a subsequent stimulus. Thus, voluntary temporal attention may have distinctive neural mechanisms to support specific demands of the sequential processing of stimuli.
人类大脑在处理一系列刺激中的每个项目时，能力面临重大限制。自愿性时间注意力可以在时间上的竞争项目中选择性地优先处理与任务相关的项目，以缓解这些限制。然而，大脑中选择性时间注意力在何时何地调节优先项目的视觉表征仍不清楚。在这里，我们在一个双目标时间提示任务中操纵对连续刺激的时间注意力，同时通过完全可预测的刺激时间来控制时间预期。我们使用脑磁图和时间分辨解码来追踪人类观察者中刺激表征的时空演变。我们发现，时间注意力在目标出现后约250毫秒增强了第一个目标的表征，在一个跨越左额叶皮层和扣带回皮层的连续区域。结果表明，自愿性时间注意力在中间处理阶段会调动腹侧流以外的皮层区域，以放大目标刺激的表征。这种将刺激信息路由到前脑区域的方式可能会保护视觉皮层免受后续刺激的干扰。因此，自愿性时间注意力可能具有独特的神经机制来支持刺激序列处理的特定需求。
