Institute of Psychology, Chinese Academy of Sciences
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Advances in food flavor analysis and sensory evaluation techniques and applications: Traditional vs emerging
No full textFood flavor represents a complex, multisensory experience shaped by the interplay of volatile and non-volatile components, texture, and consumer perception. This review examines both traditional and emerging technologies in food flavor analysis, focusing on their applications, strengths, and limitations. Although traditional methods, such as sensory evaluation and chemical analysis, provide valuable insights, they are constrained by subjectivity and the inability to fully capture the dynamic nature of flavor perception. In contrast, emerging interdisciplinary approaches—integrating neuroimaging techniques and machine learning—are offering a deeper understanding of how flavors are processed by the brain and how they influence consumer behavior. The future of flavor analysis is likely to depend on the integration of chemical, sensory, psychological, and neurological data, which will enable a more comprehensive, personalized, and dynamic approach. Such integration is expected to advance our understanding of flavor perception and drive innovations in food product development, thereby enhancing consumer satisfaction.</p
Decreased Memory Suppression Ability in Restrained Eaters on Food Information-Evidence from ERP Experiment
No full textBackground/Objectives: Food-related memory influences appetite regulation, with memory inhibition potentially reducing cravings. While obesity is linked to inhibitory deficits, how restrained eating affects memory suppression in healthy-weight individuals remains unclear. This study examined the cognitive and neural mechanisms of food-memory suppression in young women. Methods: Forty-two female participants completed a think/no-think task with high-/low-calorie food cues while an EEG was recorded. Event-related potentials (ERPs) were assessed and time-frequency analyses (theta/beta oscillations) were performed. Results: Restrained eaters showed reduced memory control for both food types. The ERP analysis revealed significant N200 amplitude differences between think/no-think conditions (p = 0.03) and a significant interaction between food calories and think/no-think conditions (p = 0.032). Theta oscillations differed by group, food calories, and conditions (p = 0.038), while beta oscillations reflected food-cue processing variations. Conclusions: In conclusion, restrained eaters exhibit distinct neural processing and attenuated food-memory suppression. These results elucidate the neurocognitive mechanisms underlying dietary behavior, suggesting that targeted interventions for maladaptive eating could strengthen memory inhibition.</p
Form information modulates the temporal dynamics of walking direction and body orientation processing in biological motion perception
No full textBiological motion (BM) perception is crucial for survival and social interaction. Previous studies have shown that form structure influences the perception of walking direction and body orientation. However, the neural mechanisms underlying how form modulates the processing of these features remain unclear. To investigate how form is encoded and its interaction with the processing of walking direction and body orientation, we combined EEG and multivariate pattern analyses. Participants viewed classic point-light displays with different forms, walking directions, and body orientations. The decoding results revealed that form information was significantly decoded starting around 85 ms, peaking at 275 ms. The time generalization analysis revealed that the neural representation of form was transient before similar to 200 ms, and became stable thereafter. Importantly, decoding accuracy became significant at 100 ms for both body orientation and walking direction when form was intact, but remained at chance level for walking direction and was reduced for body orientation when form was scrambled. These results indicate that form structure influences the time course of body orientation and walking direction processing. These findings shed light on the encoding of form structure and its role in shaping the neural representation of other BM features.</p
A whole-brain voxel-based analysis of structural abnormalities in PTSD: An ENIGMA-PGC study
No full textBackground: Patients with posttraumatic stress disorder (PTSD) exhibit smaller regional brain volumes in commonly reported regions including the amygdala and hippocampus, regions associated with fear and memory processing. In the current study, we have conducted a voxel-based morphometry (VBM) meta-analysis using whole-brain statistical maps with neuroimaging data from the ENIGMA-PGC PTSD working group.
Methods: T1-weighted structural neuroimaging scans from 36 cohorts (PTSD n = 1309; controls n = 2198) were processed using a standardized VBM pipeline (ENIGMA-VBM tool). We meta-analyzed the resulting statistical maps for voxel-wise differences in gray matter (GM) and white matter (WM) volumes between PTSD patients and controls, performed subgroup analyses considering the trauma exposure of the controls, and examined associations between regional brain volumes and clinical variables including PTSD (CAPS-4/5, PCL-5) and depression severity (BDI-II, PHQ-9).
Results: PTSD patients exhibited smaller GM volumes across the frontal and temporal lobes, and cerebellum, with the most significant effect in the left cerebellum (Hedges' g = 0.22, p(corrected) = .001), and smaller cerebellar WM volume (peak Hedges' g = 0.14, p(corrected) = .008). We observed similar regional differences when comparing patients to trauma-exposed controls, suggesting these structural abnormalities may be specific to PTSD. Regression analyses revealed PTSD severity was negatively associated with GM volumes within the cerebellum (p(corrected) = .003), while depression severity was negatively associated with GM volumes within the cerebellum and superior frontal gyrus in patients (p(corrected) = .001).
Conclusions: PTSD patients exhibited widespread, regional differences in brain volumes where greater regional deficits appeared to reflect more severe symptoms. Our findings add to the growing literature implicating the cerebellum in PTSD psychopathology
A Replicable and Generalizable Neuroimaging-Based Indicator of Pain Sensitivity Across Individuals
No full textRevealing the neural underpinnings of pain sensitivity is crucial for understanding how the brain encodes individual differences in pain and advancing personalized pain treatments. Here, six large and diverse functional magnetic resonance imaging (fMRI) datasets (total N = 1046) are leveraged to uncover the neural mechanisms of pain sensitivity. Replicable and generalizable correlations are found between nociceptive-evoked fMRI responses and pain sensitivity for laser heat, contact heat, and mechanical pains. These fMRI responses correlate more strongly with pain sensitivity than with tactile, auditory, and visual sensitivity. Moreover, a machine learning model is developed that accurately predicts not only pain sensitivity (r = 0.20 similar to 0.56, ps 200 for univariate whole brain correlation analysis and >150 for multivariate machine learning modeling. Altogether, this study demonstrates that fMRI activations encode pain sensitivity across various types of pain, thus facilitating interpretations of subjective pain reports and promoting more mechanistically informed investigations into pain physiology
Discovering Semantic Subdimensions through Disentangled Conceptual Representations
No full textUnderstanding the core dimensions of conceptual semantics is fundamental to uncovering how meaning is organized in language and the brain. Existing approaches often rely on predefined semantic dimensions that offer only broad representations, overlooking finer conceptual distinctions. This paper proposes a novel framework to investigate the subdimensions underlying coarse-grained semantic dimensions. Specifically, we introduce a Disentangled Continuous Semantic Representation Model (DCSRM) that decomposes word embeddings from large language models into multiple sub-embeddings, each encoding specific semantic information. Using these sub-embeddings, we identify a set of interpretable semantic subdimensions. To assess their neural plausibility, we apply voxel-wise encoding models to map these subdimensions to brain activation. Our work offers more fine-grained interpretable semantic subdimensions of conceptual meaning. Further analyses reveal that semantic dimensions are structured according to distinct principles, with polarity emerging as a key factor driving their decomposition into subdimensions. The neural correlates of the identified subdimensions support their cognitive and neuroscientific plausibility.</p
Functional Interaction Between the Hippocampus and Cortex During Offline Memory Reactivation
No full text记忆在大脑中是一个不断演化的动态过程，其中一些记忆随着时间的推移而历久弥新，而另一些则逐渐淡化甚至消失。研究者们长期以来一直致力于探索这一现象背后的神经机制。目前普遍认为，大脑的离线状态（如静息或睡眠）在记忆巩固和演化中起着至关重要的作用。根据记忆巩固理论，新形成的记忆最初储存在海马体中，而在离线状态下，这些记忆逐渐转移到新皮层，形成稳定的长期记忆。离线期间的记忆重激活现象反映了这一记忆转移的过程。因此，理解海马体与新皮层在记忆重激活过程中的动态交互，对于揭示记忆巩固的神经机制至关重要。然而，受限于信号采集技术的时空分辨率，相关研究尚未深入。本论文结合人类颅内脑电技术（intracranial EEG）与目标记忆重激活范式（targeted memory reactivation, TMR），探讨记忆重激活期间海马体与皮层的神经活动特征与交互模式。具体而言，研究一聚焦于清醒静息状态下记忆重激活的神经机制；研究二探讨睡眠期间的目标记忆重激活；研究三构建皮层-海马神经计算模型，解析离线期记忆转移与巩固的神经计算机制。
研究一发现，休息期的记忆重激活强度在记忆痕迹之间存在竞争，并且海马 -皮层的信息交互在重激活期间增强，具体表现为海马尖波涟漪发生率的升高和海马-皮层在 theta 频带的连通性增强。研究二发现，睡眠中声音刺激会诱发多次重激活现象，并且多次重激活之间对应着不同的海马和皮层的活动状态。其中，第一次重激活期间，海马尖波涟漪发生率升高，海马和皮层的连通性增强；第二次重激活期间，皮层的纺锤波活动增强，海马和皮层的连通性下降。这种重激活期间海马-皮层从耦合到解耦合状态的动态变化是记忆巩固领域的全新发现，有助于揭示记忆巩固背后复杂的神经机制。研究三通过计算建模仿真模拟了记忆巩 固与泛化的实验现象，提出了记忆的精确性和泛化性之间不可兼得的观点，并发现海马体中情景神经元的比例在平衡记忆精确性与泛化之间起关键作用。
总体而言，本论文扩展了对离线期记忆巩固神经机制的理解，明确了海马皮层信息交互在记忆重激活中的重要作用，并通过神经计算模型为记忆巩固与泛化过程提供了新的视角。</p
Cerebellar Function Representation and Neuromodulation of Reward Processing in People with Schizophrenia and Social Anhedonia
No full text动机缺乏与快感缺失是精神分裂症阴性症状动机维度的核心表现，也是社会快感缺失特质个体的关键特征，其心理机制主要源于奖赏加工的异常。传统神经机制研究主要聚焦于皮层-纹状体回路，难以全面阐释奖赏加工异常的复杂病理机制。近年来，随着小脑非运动功能研究的深入，其在奖赏加工中的关键作用日益凸显：它不仅直接参与奖赏期待、即时性体验、奖赏学习及努力决策等多阶段加工，还通过与奖赏网络的功能连接实现跨脑区调控。临床研究发现，精神分裂症患者与社会快感缺失个体表现出奖赏加工相关的小脑激活异常，以及小脑与奖赏网络核心区域功能连接的改变，但异常的模式及其与症状的关联仍存在争议。此外，小脑作为神经调控的重要靶点，在非运动功能调节及阴性症状干预方面的潜力已初步显现，但其对奖赏加工的调控效应仍有待阐明。基于此，本论文通过三项研究，系统探讨了精神分裂症与社会快感缺失个体中奖赏加工相关的小脑功能表征，并验证小脑神经调控的效果。
研究一利用静息态功能磁共振成像探讨小脑与奖赏网络的功能连接。实验一采用双样本验证设计（样本 1：62 例精神分裂症患者/61 例健康对照；样本2：53 例精神分裂症患者/55 例健康对照），发现患者基底神经节区域（背侧纹状体与苍白球）与小脑（后叶 Crus I 叶、VI 叶及蚓部 IV&V 区）的功能连接显著减弱，且连接强度越弱，动机维度症状越严重。
实验二纳入 355 例非临床样本，按社会快感缺失特质水平分为高（144 例）、 中（113 例）、低（128 例）三组，比较高分组与低分组间功能连接的差异，并分析其在整体样本中与特质及症状的相关性。结果显示，小脑与奖赏网络的功能连接在高低分组间无显著差异，但在整体样本中，小脑内部（蚓部 VIII、IX、X 区）的功能连接增强与动机维度缺损表现呈显著正相关。
研究二结合元分析和任务态脑成像，探讨精神分裂症患者与社会快感缺失个体在奖赏加工任务中的小脑功能表征。实验三基于对 37 项脑成像研究的元分析发现，精神分裂症谱系群体在奖赏即时性体验中左侧小脑 IV/V 叶激活降低，奖赏学习阶段左侧小脑 Crus I 区激活降低。
实验四探讨精神分裂症患者中小脑功能异常的亚组特异性，纳入重度阴性症状患者 29 例、非重度阴性症状患者 34 例和健康对照组 33 例，采用金钱奖赏延迟（MID）任务诱发脑激活。结果显示，重度阴性症状患者在奖赏期待中基底神经节（苍白球、尾状核、壳核）与小脑 I-IV 叶激活降低，并伴随两区域间功能连接增强；而非重度阴性症状患者仅表现基底神经节激活减弱。对所有患者的相关分析表明，小脑 I-IV 叶激活程度与动机维度症状呈显著负相关。
实验五采用改编 MID 任务，解析精神分裂症患者在奖赏加工中多阶段（奖赏期待、即时性体验及奖赏学习预测误差）相关的脑功能异常。对 76 例精神分裂症患者与 72 例健康对照的分析发现，健康对照在三个奖赏加工阶段中均表现出小脑后叶的激活，而患者组在即时性体验阶段小脑后叶 Crus I/II 及其他相关区域（额叶、楔前叶等）的激活显著弱于健康对照。
实验六延续实验五的任务设计，纳入 233 例非临床样本（包括高分组 83 例, 中分组 69 例，低分组 81 例），发现与社会快感缺失高分组相较低分组，在奖赏期待过程中小脑 I-IV 区激活呈降低趋势，且对于整体样本，该区域激活程度与社会快感缺失特质水平呈显著负相关。
研究三进一步探讨靶向小脑的神经调控对奖赏加工的影响。实验七采用单盲随机对照设计，纳入了 63 例非临床个体，随机分为真刺激组（31 例）和伪刺激组（32 例），接受靶向小脑的高精度直流电刺激。结果显示，与伪刺激相比，真刺激能有效维持奖赏的期待性和即时性积极情绪，并对奖赏学习率产生边缘显著的影响，但未显著影响基于奖赏的努力决策行为。
综上，本论文系统揭示了精神分裂症患者与社会快感缺失个体奖赏加工相关的小脑功能表征改变，并验证了小脑神经调控对于奖赏加工的影响。研究深化了对小脑在奖赏加工及动机维度症状中作用的理解，强调了小脑-奖赏网络在精神分裂症谱系病理机制中的重要地位，并为未来基于小脑的精准干预策略提供了重要支持。</p
Exploratory Research on Defensive Decision-Making: Phenomena, Mechanisms, and Intervention Approaches
No full text防御性决策（defensive decision-making）是一种在现实生活中普遍存在但鲜少被系统研究的决策现象。决策者出于自我保护的动机，不选择对委托人最优但 可能带来问责风险的选项，而选择对委托人次优但能够规避问责风险的选项。这种决策行为在医疗健康、工业工程、金融投资、公共管理等领域广泛存在，造成了严重的负面影响和社会资源浪费。
目前学界对防御性决策的研究主要集中在医疗领域，且多关注导致防御性决策的外部因素（如问责制度），而对决策者内部心理机制的探讨相对不足。同时， 如何有效干预防御性决策，促使决策回归到为委托人"效用最大化"的轨道上，也缺乏系统研究。基于此，本研究通过三个系列实验，系统探究了防御性决策的普遍性特征、内部心理机制及其干预策略。
研究一通过问卷调查和情境实验，考察了防御性决策在中国情境下的普遍性特征，并比较了专业人员（医护人员）与非专业人员在防御性决策倾向上的差异。研究二基于大样本数据探索了防御性决策的心理机制，重点考察了不同时间取向（跨期决策偏好）在防御性决策中的作用，并通过中介模型揭示了政策压力通过对自己/他人利益的考量及决策信心三个中介变量影响防御性决策的具体路径。 研究三系统评估了三种可能的干预策略：决策模式转换（接受 vs.拒绝）、查询内容改变（现在原因：好想法 vs. 坏想法；未来结果：好结果 vs. 坏结果；现在原 因 vs.未来结果）和决策视角转换（为自己 vs.为他人）。
研究发现，与德国被试群体相比，防御性决策在中国情境下更为普遍，且专业人员（医护人员）表现出更强的防御性决策倾向。在机制层面，越倾向于做出防御性决策的决策者，越倾向于在跨期决策中表现出对“现在失去，未来得到”这 一模式的偏好。政策压力主要通过影响个体对自身利益和他人利益的考虑程度来影响防御性决策，主要通过决策信心这一中介变量来影响决策后的负性情绪。在干预策略中，自我-他人视角转换是唯一一种能够同时降低防御性决策倾向和负性情绪的有效方法，而决策模式转换（将决策的接受模式转换为拒绝模式）与查询内容改变（优先查询防御性选项的负面信息与未来结果）虽然能降低防御性决 策倾向，但同时伴随着负性情绪的增强。
本研究不仅拓展了防御性决策的研究视野，也提供了一系列可能的助推工具箱。通过探索自我-他人视角转换、接受 vs.拒绝反应模式转换、改变决策时查询内容等干预手段，为将防御性决策拉回到为委托人“效用最大化”正轨上提供了新的思路。这些发现对于在更广的视角、更大的框架中理解和干预防御性决策具有重要意义，也为未来研究者和实践者共同努力降低防御性决策造成的伤害提供了理论基础和实践指导。</p
The Intervention Effect of High-Precision Transcranial Direct Current Stimulation on Cognitive Impairment in Schizophrenia and Its Electrophysiological Mechanisms
No full text精神分裂症是具有高度致残性的严重精神疾病，往往存在认知障碍，严重影响患者的社会功能和预后。目前，临床上治疗精神分裂症主要依靠抗精神病药物，其副作用大，并且在改善阴性症状和认知功能方面效果有限。近年来，神经调控技术开始应用于精神疾病的临床干预。其中，高精度经颅直流电刺激（High Definition-Transcranial Direct Current Stimulation, HD-tDCS）具有精度高，强度大，副作用小，效果好的优势。本研究旨在探讨 HD-tDCS 对改善精神分裂症患者临床症状和认知功能的效果，以及其电生理机制。
研究一采用横断面设计，比较了精神分裂症患者与健康人在认知功能评分方面的差异，以及 TMS 诱发电位（（TMS-evoked potential, TEP）特征值和频段功率。精神分裂症状采用阳性与阴性症状量表（Positive and Negative Syndrome Scale, PANSS）评估，被试的认知功能采用可重复神经心理状态评定量表（Repeatable Battery for the Assessment of Neuropsychological Status, RBANS）评估。经颅磁刺激同步脑电（Transcranial Magnetic Stimulation-Electroencephalography, TMS-EEG） 数据使用全脑平均场振幅（Global Mean Field Amplitude, GMFA）方法获取全脑电极电位并平均，以计算 TEP 的波幅。结果发现，精神分裂症患者存在显著的认知损伤，且在脑电指标上存在异常，表现于 TEP 各特征值和频段功率与健康 人存在显著差异；且这些脑电指标与精神分裂症患者的症状和认知功能损伤存在关联。
研究二采用纵向随机对照设计，将入组患者随机分为 HD-tDCS 真刺激组和 伪刺激组，进行为期 20 天的 20 次 HD-tDCS 干预，比较治疗前后的症状和认知功能得分，以测量 HD-tDCS 的干预效果。混合方差分析表明，组别×时间对临床症状和认知功能均有显著的交互效应。与伪刺激相比，真刺激组 PANSS 各项得分有显著降低，RBANS 各项得分则显著提高。
研究三基于研究二的结果，比较了治疗前后 HD-tDCS 组和伪刺激组在TEP 特征值方面的变化，并探讨了这些变化与患者症状及认知功能改善程度的关系。结果发现，HD-tDCS 干预显著提升患者 N100 波幅，且该提升与临床症状的改善有关。P180 波幅的提升也与临床症状改善有关。而基线期左侧背外侧前额叶脑区的 N45 波幅、N100 波幅与 RBANS 视觉空间功能的改善程度呈显著正相关。
结论：HD-tDCS 能够显著减轻精神分裂症患者的临床症状，并增强其认知功能。HD-tDCS 的干预效果可能通过调节大脑皮层的兴奋性-抑制性平衡，以及促进神经可塑性的改善实现。</p
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