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中文题名:

 基于预期线索的视觉空间注意机制研究    

姓名:

 赵晨光    

保密级别:

 公开    

论文语种:

 中文    

学科代码:

 04020001    

学科专业:

 01基础心理学(040200)    

学生类型:

 博士    

学位:

 理学博士    

学位类型:

 学术学位    

学位年度:

 2021    

校区:

 北京校区培养    

学院:

 心理学部    

研究方向:

 基础视觉    

第一导师姓名:

 宋艳    

第一导师单位:

 北京师范大学心理学部    

提交日期:

 2021-06-18    

答辩日期:

 2021-06-07    

外文题名:

 The Mechanisms of Cue-dependent Anticipatory Visuospatial Attention    

中文关键词:

 视觉空间注意 ; 事件相关电位 ; 脑电频谱 ; 近红外光学成像 ; 经颅光生物调节    

外文关键词:

 Visuospatial attention ; Event-related potentials ; EEG frequency spectrum ; fNIRS ; tPBM    

中文摘要:

视觉空间注意可以被分为预期的注意准备和暂时性的注意转移。预期的注意准备通常是在注意转移发生前,由视觉线索诱发特定区域的神经元持续性调制的过程。暂时性的注意转移则是在视觉搜索过程中对同时出现的多个刺激进行快速识别及选择的过程。在视觉空间注意的研究中一直存在着一个基本的问题:预期的注意准备如何促进随后的注意转移和行为表现?虽然,目前大部分研究主要集中在探究注意的脑电机制和血氧动力学机制上,但很少有研究将二者结合并探究注意潜在的神经血氧耦合机制。此外,经颅光生物调节技术transcranial photobiomodulation, tPBM)作为一种可提高前额叶的血氧代谢水平的无创干预手段,尚不清楚是否可以通过调节前额叶的血氧水平来调控空间注意以及相关过程。为了解决以上这些问题,我们系统地开展了三个研究(共八个实验)来更好地理解大脑如何根据预期视觉线索的提示去调控随后的注意过程。我们还提出通过tPBM调控空间注意以提高视觉工作记忆的新方法。

研究一采用快速事件相关任务的实验设计,在提示目标或干扰物的任务中同时记录了32名成人的脑电(Electroencephalogram, EEG)数据和功能性近红外光谱(functional near-infrared spectroscopy, fNIRS)的数据。从脑电数据中,我们发现了对目标的预期会在大脑后侧诱发一个早期的正向alpha(8 ~ 12 Hz)能量的偏侧化调制,对干扰物的预期则会诱发一个后期负向的alpha偏侧化的调制。从fNIRS数据中,我们发现对目标或干扰物的预期会在不重叠的纹外皮层区域诱发对侧的氧合血红蛋白(oxy-hemoglobin, HbO)活动相对于同侧脑区的显著增强的现象。更重要的是我们发现了alpha活动和HbO信号之间特定的神经血氧耦合关系。这种关系表现为在目标预期过程中正向的耦合效应和在干扰物预期过程中负向的耦合效应。

研究二中采用Posner范式的变式,对健康成年人进行了两个脑电实验(实验一:21名,实验二:32名)。通过检验预期阶段alpha能量偏侧化调制与随后注意选择相关的事件相关电位(event-related potential, ERP)之间的关系,我们探讨了预期阶段的神经振荡对注意选择过程的贡献。在提示目标的试次中,我们发现正向alpha调制指数的大小与随后的目标诱发的ERP 成分NT(target negativity)波幅呈正相关。相反,我们发现对干扰物的预期诱发的负向alpha调制指数与随后干扰物诱发的ERP 成分PD(distractor positivity)波幅呈负相关。因为PD的波幅反映了干扰物被动抑制的过程,因此这种关系解释为预期阶段对干扰物的主动抑制越强,选择阶段对干扰物的被动抑制越弱。接下来通过调整目标或干扰物线索对空间提示的范围,我们进一步发现与刺激编码相关的Ppc(posterior contralateral positivity)波幅随着预期阶段目标提示诱发的alpha 调制指数的增加而增加,从而伴随着随后NT波幅的降低。我们还发现与干扰物相关的PD成分随着预期阶段负向alpha调制指数增加而降低。综上,我们的结果表明个体暂时性注意转移过程的生物标记(反应为目标增强NT、干扰抑制PD)受到预期阶段线索诱发的alpha偏侧化的不同方式的调控。

研究三采用严格的双盲和控制对照实验设计,选用不同波长的tPBM对91名健康被试的前额叶皮层(prefrontal cortex, PFC)进行干预。考察个体基于视觉线索的空间注意及其相关过程是否能够得到改变,同时记录了任务态的脑电数据用来寻找行为变化背后相对应的神经生理学反应。结果在四组实验中均未发现tPBM对注意控制过程直接相关的行为和脑电信号有显著的影响。有趣的是我们发现在右侧PFC上施加1064 nm tPBM,对注意范围和相应的神经标记物CDA(contralateral delay activity)均有显著影响。并且发现CDA波幅的变化可以预测行为上的提高。进一步我们发现这些行为的改善和相应的脑电的改变特异于tPBM的波长(1064 nm)和照射区域(右侧PFC)。如果改变照射波长(852 nm)或刺激区域(左侧PFC),行为的改善和相应的脑电变化就会消失。我们这些实验提供了证据表明对右侧PFC施加1064 nm的tPBM可以在视觉工作记忆中提高空间注意的范围。

外文摘要:

Selective attention can be separated into two aspects: preparatory attention and transient attention shifts. In experimental design, preparatory attention is usually induced by cues with sustained cortical facilitation in neural masses representing specific aspects of the visual scene. Transient attention shifts were considered as the responses to the occurrence of targets during a visual search. One fundamental question is how preparatory attention facilitates subsequent neural processing and behavioral performance. In particular, most of these researches focused on EEG mechanisms or hemodynamic mechanisms underlying selective enhancement and inhibition, respectively. Little is known about their underlying neurovascular mechanisms. In addition, transcranial photobiomodulation (tPBM) is a novel and noninvasive intervention with the up-regulation of vascular oxygen metabolism. It is still unclear whether tPBM can enhance spatial attention or related working memory capacity in humans by modulating brain activity. To address these issues, eight experiments in three studies were performed to gain a better understanding of how the brain prepares to enhance relevant input and inhibit distracting input to support visual attention-related processes.

Study One consisted of two experiments with a rapid event-related experimental design. We recorded simultaneous electroencephalographic (EEG) and functional near-infrared spectroscopy (fNIRS) data from human adults when they were pre-cued by the visual field of coming target or distractor. From the EEG data, we found an early positive-going alpha (8 ~ 12 Hz) modulation index for target anticipation, a late negative-going modulation index for distractor anticipation within the posterior brain. From the fNIRS data, we found enhancements of hemodynamic activity in response to both the target and the distractor anticipation but within nonoverlapping posterior brain regions. More importantly, we described the specific neurovascular modulation between alpha power and oxygenated Hemoglobin (HbO) signal, which showed a positive coupling effect during target anticipation and a negative coupling effect during distractor anticipation. Such flexible neurovascular couplings between EEG oscillation and hemodynamic activity seem to play an essential role in the final behavioral outcomes.

In Study Two, two EEG experiments were performed in healthy adults under several variants of the Posner paradigms. We explored the potential contribution of anticipatory EEG oscillations by examining how anticipatory modulation of alpha-band power influences the subsequent ERP marker of attentional selection. For target cueing trials, we found that the magnitude of the positive-going alpha modulation index was positively correlated with subsequent target-evoked ERP (NT) amplitudes. Importantly, we found the distractor-induced alpha modulation index negatively correlated with the subsequent ERP (PD) amplitudes assumed to reflect distractor inhibition. That is, the more active inhibition responded to distractor-attended cue, the less passive inhibition responded to the distractor was. Such different directions of alpha-ERP couplings seem to play an important role in the functional inhibition of selective attention. By adapting the cueing scope of target or distractor, we further found that the target-related alpha MI increased with increasing Ppc, resulting in a decreased NT. we also found that the distractor-related negative alpha MI increased with a decreasing PD. Taken together, our results suggest that each individual's attentional selection biomarkers (NT and PD) were influenced by the anticipation-induced alpha lateralization differently.

In Study Three, we delivered double-blind and sham-control tPBM with different wavelengths to the prefrontal cortex (PFC) of 91 healthy participants and conducted four EEG experiments to investigate whether individual visual cue-dependent attention control and attention scope could be modulated. If so, we could find related neuropsychological responses. We did not find any tPBM effects on attention control in four experiments. Interestingly, we found that 1064 nm tPBM applied on the right PFC has both a substantial impact on attention scope (K value) and scope-related neural response (CDA), no matter orientation or color feature of objects was memorized. Moreover, this neural enhancement could track the behavioral benefits. However, these behavioral benefits and the corresponding EEG changes disappeared with 852 nm wavelength or with the stimulation site on the left PFC. Our findings provided the converging evidence highlighting 1064 nm tPBM applied on the right PFC can improve attention scope and related working memory processing.

参考文献总数:

 221    

馆藏地:

 图书馆学位论文阅览区(主馆南区三层BC区)    

馆藏号:

 博040200-01/21003    

开放日期:

 2022-06-18    

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