Neurosciences Graduate Program, University of California, San Diego, La Jolla, California 92093-0109,
Neurosciences Graduate Program, University of California, San Diego, La Jolla, California 92093-0109.
J Neurosci. 2018 Jun 13;38(24):5632-5648. doi: 10.1523/JNEUROSCI.3638-17.2018. Epub 2018 May 17.
Two factors play important roles in shaping perception: the allocation of selective attention to behaviorally relevant sensory features, and prior expectations about regularities in the environment. Signal detection theory proposes distinct roles of attention and expectation on decision-making such that attention modulates early sensory processing, whereas expectation influences the selection and execution of motor responses. Challenging this classic framework, recent studies suggest that expectations about sensory regularities enhance the encoding and accumulation of sensory evidence during decision-making. However, it is possible, that these findings reflect well documented attentional modulations in visual cortex. Here, we tested this framework in a group of male and female human participants by examining how expectations about stimulus features (orientation and color) and expectations about motor responses impacted electroencephalography (EEG) markers of early sensory processing and the accumulation of sensory evidence during decision-making (the early visual negative potential and the centro-parietal positive potential, respectively). We first demonstrate that these markers are sensitive to changes in the amount of sensory evidence in the display. Then we show, counter to recent findings, that neither marker is modulated by either feature or motor expectations, despite a robust effect of expectations on behavior. Instead, violating expectations about likely sensory features and motor responses impacts posterior alpha and frontal theta oscillations, signals thought to index overall processing time and cognitive conflict. These findings are inconsistent with recent theoretical accounts and suggest instead that expectations primarily influence decisions by modulating post-perceptual stages of information processing. Expectations about likely features or motor responses play an important role in shaping behavior. Classic theoretical frameworks posit that expectations modulate decision-making by biasing late stages of decision-making including the selection and execution of motor responses. In contrast, recent accounts suggest that expectations also modulate decisions by improving the quality of early sensory processing. However, these effects could instead reflect the influence of selective attention. Here we examine the effect of expectations about sensory features and motor responses on a set of electroencephalography (EEG) markers that index early sensory processing and later post-perceptual processing. Counter to recent empirical results, expectations have little effect on early sensory processing but instead modulate EEG markers of time-on-task and cognitive conflict.
将选择性注意分配给与行为相关的感觉特征，以及对环境中规律的先验期望。信号检测理论提出了注意和期望对决策的不同作用，即注意调节早期感觉处理，而期望影响运动反应的选择和执行。挑战这一经典框架，最近的研究表明，对感觉规律的期望增强了决策过程中感觉证据的编码和积累。然而，这些发现可能反映了视觉皮层中已有充分记录的注意力调节。在这里，我们通过检查参与者对刺激特征（方向和颜色）和运动反应的期望如何影响决策过程中早期感觉处理和感觉证据积累的脑电图（EEG）标记物（早期视觉负电位和中顶正电位），在一组男性和女性人类参与者中测试了这一框架。我们首先证明这些标记物对显示中感觉证据数量的变化敏感。然后，与最近的发现相反，尽管期望对行为有显著影响，但这两种标记物都不受特征或运动期望的调节。相反，违反对可能的感觉特征和运动反应的期望会影响后阿尔法和额前 theta 振荡，这些信号被认为是整体处理时间和认知冲突的指标。这些发现与最近的理论观点不一致，表明期望主要通过调节信息处理的后知觉阶段来影响决策。对可能的特征或运动反应的期望在塑造行为方面起着重要作用。经典理论框架假设，期望通过偏向决策的后期阶段（包括运动反应的选择和执行）来调节决策。相比之下，最近的观点表明，期望还通过改善早期感觉处理的质量来调节决策。然而，这些影响可能反映了选择性注意的影响。在这里，我们检查了对感觉特征和运动反应的期望对一组脑电图（EEG）标记物的影响，这些标记物可以指示早期感觉处理和后期知觉后处理。与最近的实证结果相反，期望对早期感觉处理几乎没有影响，而是调节了与任务时间和认知冲突有关的脑电图标记物。
