Heimer-McGinn Victoria R, Wise Taylor B, Halter Emma R, Martin Dominique, Templer Victoria L
Department of Psychology and Program in Neuroscience, Providence College, United States; Department of Psychology, Roger Williams University, United States.
Department of Psychology and Program in Neuroscience, Providence College, United States; Department of Cognitive and Psychological Sciences, Brown University, United States.
Neurobiol Learn Mem. 2024 Dec;216:108004. doi: 10.1016/j.nlm.2024.108004. Epub 2024 Oct 31.
The human posterior parietal cortex (PPC) is known to support sustained attention. Specifically, top-down attention is generally processed in dorsal regions while bottom-up regulation occurs more ventrally. In rodent models, however, it is still unclear whether the PPC is required for sustained attention, or whether there is a similar functional dissociation between anatomical regions. Consequently, the aim of this study was to investigate the contribution of the rodent dorsal PPC (dPPC) in sustained attention. We used the five-choice serial reaction time task (5CSRTT) and compared rats with neurotoxic dPPC lesions to sham operated rats. We found that rats with dPPC lesions were less accurate and took longer to make correct choices, indicating impaired attention and reduced processing speed. This effect, however, was limited to the first few days of post-operative testing. After an apparent recovery, omissions became elevated in the lesion group, which, in the absence of reduced motivation and mobility, can also be interpreted as impaired attention. In subsequent challenge probes, the lesion group displayed globally elevated latency to make a correct response, indicating reduced processing speed. No differences in premature responses or perseverative responses were observed at any time, demonstrating that dPPC lesions did not affect impulsivity and compulsivity. This pattern of behavior suggests that while intact dPPC supports goal-driven (top-down) modulation of attention, it likely does not play a central role in processing stimulus-driven (bottom-up) attention. Furthermore, compensatory mechanisms can support sustained attention in the absence of a fully functioning dPPC, although this occurs at the expense of processing speed. Our results inform the literature by confirming that rodent PPC is involved in regulating sustained attention and providing preliminary evidence for a functional dissociation between top-down and bottom-up attentional processing.
已知人类后顶叶皮层（PPC）支持持续注意力。具体而言，自上而下的注意力通常在背侧区域进行处理，而自下而上的调节则更多地发生在腹侧区域。然而，在啮齿动物模型中，PPC是否是持续注意力所必需的，或者解剖区域之间是否存在类似的功能分离仍不清楚。因此，本研究的目的是调查啮齿动物背侧PPC（dPPC）在持续注意力中的作用。我们使用了五选择连续反应时间任务（5CSRTT），并将患有神经毒性dPPC损伤的大鼠与假手术大鼠进行了比较。我们发现，患有dPPC损伤的大鼠准确性较低，做出正确选择所需的时间更长，这表明注意力受损且处理速度降低。然而，这种影响仅限于术后测试的最初几天。在明显恢复后，损伤组的遗漏率升高，在没有动机和活动能力降低的情况下，这也可以解释为注意力受损。在随后的挑战探针测试中，损伤组做出正确反应的潜伏期总体升高，表明处理速度降低。在任何时候都未观察到过早反应或持续性反应的差异，这表明dPPC损伤不会影响冲动性和强迫性。这种行为模式表明，虽然完整的dPPC支持目标驱动（自上而下）的注意力调节，但它可能在处理刺激驱动（自下而上）的注意力方面不发挥核心作用。此外，补偿机制可以在dPPC功能不全的情况下支持持续注意力，尽管这是以处理速度为代价的。我们的研究结果通过证实啮齿动物PPC参与调节持续注意力，并为自上而下和自下而上的注意力处理之间的功能分离提供初步证据，为该文献提供了信息。
