Centre for Human Brain Health, School of Psychology, University of Birmingham, UK.
Centre for Human Brain Health, School of Psychology, University of Birmingham, UK.
Prog Neurobiol. 2022 Jul;214:102285. doi: 10.1016/j.pneurobio.2022.102285. Epub 2022 May 6.
Attention serves an essential role in cognition and behavior allowing us to focus on behaviorally-relevant objects while ignoring distraction. Perceptual load theory states that attentional resources are allocated according to the requirements of the task, i.e., its 'load'. The theory predicts that the resources left to process irrelevant, possibly distracting stimuli, are reduced when the perceptual load is high. However, it remains unclear how this allocation of attentional resources specifically relates to neural excitability and suppression mechanisms. In this magnetoencephalography (MEG) study, we show that brain oscillations in the alpha band (8-13 Hz) implemented the suppression of distracting objects when the perceptual load was high. In parallel, high load increased the neuronal excitability for target objects, as reflected by rapid invisible frequency tagging. We suggest that the allocation of resources in tasks with high perceptual load is implemented by a gain increase for targets, complemented by distractor suppression reflected by alpha-band oscillations closing the 'gate' for interference.
注意在认知和行为中起着至关重要的作用，使我们能够专注于行为相关的物体，同时忽略干扰。知觉负载理论指出，注意力资源是根据任务的要求分配的，即其“负载”。该理论预测，当知觉负载较高时，处理不相关、可能分散注意力的刺激的资源就会减少。然而，目前尚不清楚这种注意力资源的分配如何具体与神经兴奋性和抑制机制相关。在这项脑磁图（MEG）研究中，我们表明，当知觉负载较高时，alpha 波段（8-13 Hz）的脑振荡实现了对分心物体的抑制。同时，高负载增加了目标物体的神经元兴奋性，这反映在快速不可见的频率标记上。我们认为，高知觉负载任务中的资源分配是通过目标的增益增加来实现的，辅以 alpha 波段振荡反映的分心抑制，为干扰“关门”。
