School of Psychology and Counselling, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia.
School of Psychology, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, QLD, Australia.
PLoS One. 2021 Oct 8;16(10):e0242753. doi: 10.1371/journal.pone.0242753. eCollection 2021.
Humans are constantly exposed to a rich tapestry of visual information in a potentially changing environment. To cope with the computational burden this engenders, our perceptual system must use prior context to simultaneously prioritise stimuli of importance and suppress irrelevant surroundings. This study investigated the influence of prediction and attention in visual perception by investigating event-related potentials (ERPs) often associated with these processes, N170 and N2pc for prediction and attention, respectively. A contextual trajectory paradigm was used which violated visual predictions and neglected to predetermine areas of spatial interest, to account for the potentially unpredictable nature of a real-life visual scene. Participants (N = 36) viewed a visual display of cued and non-cued shapes rotating in a five-step predictable trajectory, with the fifth and final position of either the cued or non-cued shape occurring in a predictable or unpredictable spatial location. To investigate the predictive coding theory of attention we used factors of attention and prediction, whereby attention was manipulated as either cued or non-cued conditions, and prediction manipulated in either predictable or unpredictable conditions. Results showed both enhanced N170 and N2pc amplitudes to unpredictable compared to predictable stimuli. Stimulus cueing status also increased N170 amplitude, but this did not interact with stimulus predictability. The N2pc amplitude was not affected by stimulus cueing status. In accordance with previous research these results suggest the N170 is in part a visual prediction error response with respect to higher-level visual processes, and furthermore the N2pc may index attention reorientation. The results demonstrate prior context influences the sensitivity of the N170 and N2pc electrophysiological responses. These findings add further support to the role of N170 as a prediction error signal and suggest that the N2pc may reflect attentional reorientation in response to unpredicted stimulus locations.
人类在不断变化的环境中不断接触到丰富多彩的视觉信息。为了应对由此产生的计算负担，我们的感知系统必须利用先前的上下文，同时优先处理重要的刺激物，并抑制不相关的环境。本研究通过研究与这些过程相关的事件相关电位（ERP），即分别与预测和注意力相关的 N170 和 N2pc，来研究视觉感知中的预测和注意力的影响。使用了上下文轨迹范式，该范式违反了视觉预测，并且没有预先确定空间兴趣区域，以说明现实视觉场景中潜在的不可预测性。参与者（N=36）观看了一个提示和非提示形状在五步可预测轨迹中旋转的视觉显示，第五个也是最后一个位置的提示或非提示形状出现在可预测或不可预测的空间位置。为了研究注意力的预测编码理论，我们使用了注意力和预测的因素，其中注意力被操纵为提示或非提示条件，而预测被操纵为可预测或不可预测条件。结果表明，与可预测刺激相比，不可预测刺激的 N170 和 N2pc 振幅都增强了。刺激提示状态也增加了 N170 振幅，但这与刺激可预测性没有相互作用。N2pc 振幅不受刺激提示状态的影响。与先前的研究一致，这些结果表明 N170 部分是与更高层次视觉过程有关的视觉预测误差反应，并且 N2pc 可能索引注意力重新定向。结果表明，先前的上下文会影响 N170 和 N2pc 电生理反应的敏感性。这些发现进一步支持了 N170 作为预测误差信号的作用，并表明 N2pc 可能反映了对未预测刺激位置的注意力重新定向。
