基于眼的注意调节短时程眼优势可塑性的神经机制
文献类型：学位论文
| 作者 | 宋方兴
|
| 答辩日期 | 2024-06 |
| 文献子类 | 博士 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 中国科学院心理研究所 |
| 其他责任者 | 鲍敏 |
| 关键词 | 注意 眼优势 适应 眼拮抗神经元 |
| 学位名称 | 理学博士 |
| 学位专业 | 基础心理学 |
| 其他题名 | Neural Mechanisms Underlying Short-term Ocular Dominance Plasticity Regulated by Eye-based Attention |
| 中文摘要 | Visual plasticity refers to the capacity of the visual system to undergo structural and functional changes influenced by external visual experiences. Ocular dominance plasticity, an important aspect of visual plasticity, is characterized by the reshaping of ocular dominance resulting from the impact of visual experiences. Previous studies have established that ocular dominance plasticity is most robust during the critical period, yet recent research on short-term monocular deprivation has revealed that depriving visual input of one eye in adults can result in a shift of ocular dominance towards the deprived eye. This suggests that adults retain a certain degree of ocular dominance plasticity. However, the majority of these studies have primarily focused on the effect of imbalanced visual inputs on ocular dominance plasticity, neglecting the imbalanced allocation of attentional resources between the two monocular pathways during the monocular deprivation. Therefore, whether attention can modulate shortterm ocular dominance plasticity or not is worth investigating. This paper employs the “dichoptic-backward-movie” adaptation paradigm, in which participants were presented with regular movie images in one eye (i.e., attended eye) while the other eye (i.e., unattended eye) received the backward movie images of the same episode. The advantage of the “dichoptic-backward-movie” adaptation paradigm is to balance the input energy across the eyes but leave attention unbalanced across the eyes. In this dissertation, three studies were conducted to investigate the neural mechanisms underlying the modulation of short-term ocular dominance by eyebased attention. In Study 1, frequency tagging and steady-state visual evoked potential (SSVEP) were used to measure electroencephalogram (EEG) signals of each eye during adaptation, and binocular rivalry task was used to measure ocular dominance before and after adaptation. Behavioral results showed that one hour of watching this dichoptic movie caused a shift of perceptual ocular dominance towards the unattended eye (or termed aftereffect). The EEG results showed that there were strong EEG responses in both frontal and occipital regions during the adaptation phase, and the occipital response caused by the attended-eye stimulation was stronger than that of the unattended eye. More importantly, the aftereffect positively correlated with the advantage of neural activity for the attended-eye over unattended-eye signals at the frontal electrodes. These results provide evidence for eye-based attentional modulation of ocular dominance plasticity. Moreover, the aftereffect disappeared when interocular competition was minimized during adaptation. This suggests that the binocular rivalry mechanisms play an important role in attention-induced ocular dominance shift. Therefore, we propose an adaptation mechanism of opponency neurons based on the ocular-opponency-neuron model of binocular rivalry to explain the attention-induced ocular dominance shift. The aim of Study 2 was to provide evidence for the adaptation mechanism of opponency neurons and to explore whether this mechanism also contributes to the effects of short-term monocular deprivation. To this end, we used SSVEP to assess neural signals at the intermodulation (IM) frequency which is thought to reflect interocular interactions and index opponency neuronal activity. Within the context of the “dichoptic-backward-movie” adaptation, we found evidence supporting the adaptation mechanism of opponency neurons. However, such evidence was not observed in the short-term monocular deprivation experiment. These findings point to distinct underlying mechanisms between the effects of attention-induced ocular dominance shift and those of short-term monocular deprivation. In Study 3, we combined functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) techniques to investigate the neural mechanisms underlying the shift of ocular dominance induced by “dichoptic-backwardmovie” adaptation. First, we observed robust activation in the frontal eye field (FEF), intraparietal sulcus (IPS) and superior parietal lobule (SPL) when participants were watching the dichoptic backward movie while focusing their attention on the regular movie. More importantly, the effect of attention-induced ocular dominance shift was significantly attenuated after we temporarily inhibited the cortical function of FEF via TMS. These findings suggest that the fronto-parietal attentional network is involved in controlling eye-based attention in the “dichoptic-backward-movie” adaptation paradigm, and in this network, FEF plays a crucial causal role in generating the attention-induced ocular dominance shift. In Study 3, we combined functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) techniques to investigate the neural mechanisms underlying the shift of ocular dominance induced by “dichoptic-backwardmovie” adaptation. First, we observed robust activation in the frontal eye field (FEF), intraparietal sulcus (IPS) and superior parietal lobule (SPL) when participants were watching the dichoptic backward movie while focusing their attention on the regular movie. More importantly, the effect of attention-induced ocular dominance shift was significantly attenuated after we temporarily inhibited the cortical function of FEF via TMS. These findings suggest that the fronto-parietal attentional network is involved in controlling eye-based attention in the “dichoptic-backward-movie” adaptation paradigm, and in this network, FEF plays a crucial causal role in generating the attention-induced ocular dominance shift. |
| 英文摘要 | 视觉可塑性是指视觉系统会受外界视觉经验的影响导致其结构和功能发生改变。眼优势可塑性是一种被广泛研究的视觉可塑性，表现为眼优势受视觉经验的影响而发生转移。虽然以往研究发现在生长发育的关键期内眼优势可塑性最强， 但近年来短时程单眼剥夺的研究发现对成年个体的一只眼进行剥夺会导致眼优势向剥夺眼进行转移，表明成年个体仍具有一定程度的眼优势可塑性。然而，这些研究大多都关注视觉输入的不平衡对眼优势可塑性的影响，却忽略了在单眼剥夺过程中注意资源在两条单眼通路间分配的不平衡。因此，注意是否也会对短时程眼优势可塑性产生影响是值得研究的。 本文采用“离眼倒放视频”适应范式，让被试以离眼（即双眼分离）的形式观看一段视频。其中，一只眼内呈现的是正常播放的视频画面（注意眼），而另一只眼内则是相同视频的倒放形式（非注意眼）。这样操作可以在保持两眼内视觉输入相对平衡的同时使注意更多地集中到一只眼内。我们通过三个研究深入探究了基于眼的注意对短时程眼优势可塑性的调节及其神经机制。 研究一采用频率标记技术和稳态视觉诱发电位技术来测量适应过程中被试每只眼睛的脑电信号，并在适应前后采用双眼竞争任务测量眼优势。行为结果显示，观看 1 小时的离眼倒放视频会使眼优势向非注意眼进行转移。脑电结果显示，在适应过程中额叶和枕叶区域都有较强的脑电反应，并且注意眼内刺激引起的枕叶反应强于非注意眼。更重要的是，适应过程中的额叶神经反应与适应前后的眼优势转移之间存在显著正相关。这些结果为基于眼的注意调节眼优势可塑性提供了证据。此外，我们还发现只有当适应过程和前后测中的刺激均具有眼间竞争时，眼优势转移效应才会出现。这表明双眼竞争机制在注意引起的眼优势转移中发挥着重要的作用。为此，我们根据双眼竞争的眼拮抗神经元模型提出了拮抗神经元的适应机制来解释注意引起的眼优势转移效应。 研究二的目的是为拮抗神经元的适应机制提供证据，并探究该机制是否在短时程单眼剥夺效应中也发挥作用。为此，研究二同样采用稳态视觉诱发电位技术，测量了反映眼间交互作用的交互调制频率神经信号作为拮抗神经元活动的指标。结果显示，在离眼倒放视频适应实验中发现了支持拮抗神经元适应机制的证据， 但在单眼剥夺实验中却没有发现相关证据。这些结果表明注意诱发的眼优势转移效应与单眼剥夺效应之间可能具有不同的潜在机制。 研究三结合功能性核磁共振成像技术和经颅磁刺激技术来深入探究基于眼的注意调节眼优势的神经机制并为其提供直接的因果证据。首先，我们发现当被试观看离眼倒放视频并将注意集中到正放画面上时，背侧注意网络中的额叶眼动区、顶内沟和顶上小叶出现显著的激活。更重要的是，当采用经颅磁刺激对额叶 眼动区进行抑制之后，眼优势转移效应出现明显减弱。这些结果表明在“离眼倒放视频”适应范式中额顶注意网络负责控制基于眼的注意，并且在该网络中，额叶眼动区在注意引起的眼优势转移中发挥着重要的因果作用。 综上所述，本文揭开了自上而下的基于眼的注意调节成年人短时程眼优势可塑性的神秘面纱。通过一系列研究，我们证明了一种新颖的（虽然不一定是唯一 的）借助基于眼的注意调节眼优势可塑性的机制，此机制与目前学界对短时程眼优势可塑性的主流解释“稳态平衡补偿理论”截然不同。本文也因此有力地推动了眼优势可塑性研究领域进一步的向前发展。 |
| 语种 | 中文 |
| 源URL | [http://ir.psych.ac.cn/handle/311026/47996]  |
| 专题 | 心理研究所_认知与发展心理学研究室 |
| 推荐引用方式 GB/T 7714 | 宋方兴. 基于眼的注意调节短时程眼优势可塑性的神经机制[D]. 中国科学院心理研究所. 中国科学院大学. 2024. |
入库方式： OAI收割
来源：心理研究所
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