Attention and Capacity Limits in Perception: A Cellular Metabolism Account
Attention and Capacity Limits in Perception: A Cellular Metabolism Account
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DOI：
10.1523/jneurosci.2368-19.2020
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发表时间：
2020-08-26
影响因子：
5.3
通讯作者：
Lavie, Nilli
中科院分区：
文献类型：
--
作者：
Bruckmaier, Merit;Tachtsidis, Ilias;Lavie, Nilli
知觉能力的限制导致了各种疏忽失明的现象。在这里，我们提出了一种神经生理学解释，将这些知觉能力限制直接归因于脑细胞代谢的限制。我们假设，总体大脑能量供应保持恒定，而不考虑总体心理处理需求；因此，需要一种注意力机制来调节有限的细胞代谢水平，以与所关注的任务需求保持一致。因此，任务中知觉负荷的增加(对神经计算的需求更大)应该会导致参与加工的潜在新陈代谢增加，而参与无人参与加工的新陈代谢减少。我们测试了这一预测，测量了细胞色素C氧化酶(OxCCO)的氧化状态，细胞内细胞代谢的标志。采用宽带近红外光谱分析技术，在高知觉负荷(复杂特征-联合搜索)和低负荷(特征突现搜索)条件下，记录被试(男女均可)的视皮层oxCCO水平。在随机的一半试验中，呈现了一个与任务无关的外围棋盘。我们的研究结果表明，在高知觉负荷和低知觉负荷条件下，对注意任务刺激作出反应的视觉皮层区域的oxCCO水平显著增加，而与无人注意加工相关的oxCCO水平显著降低。这些负荷效应的负时间相关性进一步支持了我们的新陈代谢权衡账户。这些结果证明了一种注意力补偿机制，该机制根据加工需求调节细胞代谢水平。此外，它们还为被广泛接受的规定提供了新的证据，即总体大脑新陈代谢水平保持不变，与心理任务需求无关，并建立了感知能力限制的神经生理学解释。
Limits on perceptual capacity result in various phenomena of inattentional blindness. Here we propose a neurophysiological account attributing these perceptual capacity limits directly to limits on cerebral cellular metabolism. We hypothesized that overall cerebral energy supply remains constant, regardless of overall mental processing demands; therefore, an attention mechanism is required to regulate limited cellular metabolism levels in line with attended task demands. Increased perceptual load in a task (imposing a greater demand on neural computations) should thus result in increased metabolism underlying attended processing, and reduced metabolism mediating unattended processing. We tested this prediction measuring oxidation states of cytochrome c oxidase (oxCCO), an intracellular marker of cellular metabolism. Broadband near-infrared spectroscopy was used to record oxCCO levels from human visual cortex while participants (both sexes) performed a rapid sequential visual search task under either high perceptual load (complex feature-conjunction search) or low load (feature pop-out search). A task-irrelevant, peripheral checkerboard was presented on a random half of trials. Our findings showed that oxCCO levels in visual cortex regions responsive to the attended-task stimuli were increased in high versus low perceptual load, whereas oxCCO levels related to unattended processing were significantly reduced. A negative temporal correlation of these load effects further supported our metabolism trade-off account. These results demonstrate an attentional compensation mechanism that regulates cellular metabolism levels according to processing demands. Moreover, they provide novel evidence for the widely held stipulation that overall cerebral metabolism levels remain constant regardless of mental task demand and establish a neurophysiological account for capacity limits in perception.