正念冥想对情绪的调节作用:理论与神经机制

正念冥想可调节个体的负性情绪、促进个体正性情绪,对于心身疾病具有显著的干预效用.正念冥想的再感知模型、正念应对模型、推动性上升螺旋模型以及正念情绪调节模型都强调了正念冥想对情绪的调节作用.认知神经科学的研究发现,正念冥想可促进左侧前额叶脑区激活增强,涉及的脑区主要包括背外侧前额叶皮层(DLPFC)和背内侧前额叶皮层(DMPFC).研究者进一步发现,正念特质是通过改善前额叶对边缘系统反应的调节来实现对情绪的调节作用.而且,这种调节作用还有可能体现为通过冥想训练分离联结在一起的两种自我参照神经机制,从而加强体验性神经机制.另外,研究者还发现,正念冥想训练还可以改变与情绪加工相关的大脑结构.进一步澄清冥想训练与大脑偏侧化的关系和不同类型被试之间的比较研究将成为该领域日后研究的重点.     

基因-大脑-行为框架下的抑制控制与老化

抑制控制能力是认知功能的重要成分。神经影像研究表明, 老年人抑制控制能力改变与前额叶皮层萎缩、神经元丧失有着密切关系, 抑制过程中前额叶需要以更高水平的激活达到代偿目的。遗传学研究表明, 抑制控制相关认知老化具有个体差异性, 大脑结构功能对个体差异的作用会出现衰退, 而遗传变异作用逐渐增加, 并使之成为认知老化个体差异性的主要原因之一。未来研究应利用遗传影像学, 结合影像学和遗传学优势, 在基因、大脑和行为框架下探索抑制控制与老化。     

左侧前额叶语言加工功能研究综述

1 引言 探讨左前额叶的认知功能是目前脑成像研究的焦点之一。前额叶皮层占人类大脑的1/3。70年代初,鲁利亚提出大脑的三个机能系统时认为,额叶属于第三机能系统,负责编制行为程序,调节、控制行为,它对于完成很多高级认知加工,如计划、控制、问题解决等有着重要作用。近年来不断有研究发现,左侧前额叶还参与了许多和语言加工有关的活动,特别是额下回、Broca区等大脑区域被研究者进行了广泛地探讨。     

不同情绪载体的神经活动及其异同——脑成像研究的ALE元分析

情绪识别一直是学界关注的热点。虽然已有研究探讨了动态面孔表情、动态身体表情和声音情绪的脑机制, 但对每种情绪载体的整体认识相对不完善, 同时对不同情绪载体之间神经机制的共性和区别知之甚少。因此, 本研究首先通过三项独立的激活似然估计元分析来识别每种情绪模式的大脑激活区域, 然后进行对比分析以评估三种情绪载体之间共同的和独特的神经活动。结果显示, 动态面孔表情的大脑活动包括广泛的额叶、枕叶、颞叶和部分顶叶皮层以及海马、小脑、丘脑、杏仁核等皮层下区域; 动态身体表情的激活集中于颞/枕叶相关脑区以及小脑和海马; 声音情绪则引起了颞叶、额叶、杏仁核、尾状核和脑岛的激活。联合分析表明, 三种情绪载体跨模态激活了左侧颞中回和右侧颞上回。对比分析的结果证明了视觉刺激比听觉刺激更占优势, 动态面孔表情尤为突出, 同时动态身体表情也发挥着重要作用, 但声音情绪有其独特性。总之, 这些发现验证和拓展了三种情绪载体的现有神经模型, 揭示了情绪处理中心的、普遍性的区域, 但每种情绪载体又有自己可靠的特异性神经回路。     

左前额叶与趋近动机加工的关系

在加工正性情绪时, 前额叶左侧激活水平大于右侧。而正性情绪往往伴随着趋近动机。因此为了探索这种现象反映的究竟是正性情绪加工还是趋近动机加工, 文章总结了两个研究领域中的有关证据：来自特质或状态愤怒情绪与左前额叶相对激活关系领域的研究证据和来自身体姿势变化(包括整体姿势变化和单侧肌肉紧缩)对左前额叶相对激活的影响领域的研究证据。前者的一致发现是：左前额叶参与加工由愤怒情绪引发的趋近动机。后者的一致发现是：不同的身体姿势能够改变左前额叶的相对激活水平。两种领域的研究证据汇聚起来证明左前额叶参与加工趋近动机。文章还指出了将来研究的注意事项和可能方向：精确定义回避型愤怒; 探索愤怒情绪是否在加工晚期诱发趋近或回避动机; 探索不同方式诱发的趋近动机是否在脑机制上存在差异。     

老化对来源记忆编码的影响——一项fMRI研究

为探讨HAROLD模型在来源记忆中的适用性以及对"补偿说"进行检验,本研究以汉语双字词为材料,采用高低两种难度水平的位置回忆任务对13名老年被试和15名年轻被试的来源记忆编码过程进行fMRI扫描,考察在编码阶段大脑额叶激活模式的年龄差异。行为研究结果发现:年龄的主效应和难度的主效应均显著;神经成像研究结果发现:在高难度条件下,老年人仅激活左侧额叶,而在低难度条件下老年人的额叶呈现出双侧激活.且无论难度高低,老年人都在右侧额下回显示出比年轻人更强的激活,但这种激活的增强和行为成绩的相关并不显著。因此,HAROLD模型具有任务特异性,并非通用模型,且本研究结果不支持补偿说。     

任务难度与老化对大脑激活的影响——以线索记忆编码为例

以汉语名词双字词对为材料,采用了两种性质、三种难度水平的线索回忆任务对12名老年被试和15名年轻被试的项目记忆编码过程进行fMRI扫描,考察在编码阶段大脑激活受任务难度变化和老化的影响。行为研究结果发现:年龄的主效应、难度的主效应以及难度与年龄交互作用均显著,即,随着任务难度的增加,老年人的成绩更加明显地低于年轻人。神经成像研究结果发现:(1)当词对的相关性降低时,大脑激活的增强主要表现为面积的增加,而当词对的频率降低时,主要表现在激活强度的增加上。(2)任务难度和大脑激活面积、强度之间均不存在对应的递增变化关系。(3)仅当词对的相关性降低时,老年人比年轻人调用了更多的额叶脑区。     

动态性对简笔画动物审美的影响及其神经机制

运用行为和fMRI技术, 通过比较动态刺激与静态刺激审美判断的行为和脑机制的异同探讨动态性对简笔画动物审美的影响, 包括两个实验。结果发现, 动态简笔画动物的美观程度评分和喜欢程度评分都显著高于静态简笔画动物。同时, 动态简笔画动物审美判断激活的区域基本涵盖了静态简笔画动物审美所激活的区域, 二者都激活了枕叶区等视觉加工区域、额叶区等认知加工区域、眶额叶皮层等奖赏区域以及海马、脑岛、扣带回、杏仁核等情绪加工区域。与静态简笔画动物的审美相比, 动态简笔画动物的审美显著激活了双侧舌回、双侧MT。本研究结果表明, 动态性影响了对简笔画动物的审美, 动态简笔画动物比静态简笔画动物被判断为更加美观。     

非情绪与情绪背景下行为抑制时外侧前额叶的功能分化:一项fNIRS研究

采用功能性近红外脑成像技术(f NIRS),结合事件相关设计,在非情绪与情绪背景下,测量个体完成go/no-go任务时外侧前额叶皮层氧合血红蛋白浓度(Hb O)的变化。结果发现:在非情绪背景下,行为抑制时双侧背外侧前额叶皮层和右眶额叶皮层负激活;在情绪背景下,行为抑制时双侧背外侧前额叶皮层和眶额皮层负激活,情绪与行为抑制的交互作用显著负激活双侧腹外侧前额叶皮层。结果表明:在非情绪与情绪背景下,双侧背外侧前额叶和右眶额叶皮层可能以神经抑制的活动形式参与行为抑制反应;腹外侧前额叶皮层可能不是行为抑制的重要脑区,但对情绪与行为抑制整合具有重要意义,特别是在负性情绪背景下,双侧腹外侧前额叶皮层可能以更大程度的神经抑制活动参与到情绪与行为抑制交互作用中来。     

语言经验对大脑激活的影响：来自第二语言初学者的证据

研究采用功能磁共振成像技术考察语言经验在塑造大脑激活模式中的作用。12名只有很少英语学习经验因而熟练程度很低的小学儿童参与了实验。结果发现,在视觉呈现的押韵判断任务中,英文任务和中文任务共同激活了左侧额下回负责语音加工的脑区。更重要的是,虽然英文任务更难,也更多地激活了双侧的顶叶区域,但是它在额叶诱发的激活强度显著低于中文。这个结果进一步说明第二语言的语音皮层表征是随着学习经验的增加而逐渐发展起来的。     

Socioemotional selectivity in older adults: Evidence from the subjective experience of angry memories

Few studies have compared the phenomenological properties of younger and older adults' memories for emotional events. Some studies suggest that younger adults remember negative information more vividly than positive information whereas other studies suggest that positive emotion yields phenomenologically richer memories than negative emotion for both younger and older adults. One problem with previous studies is a tendency to treat emotion as a dichotomous variable. In contrast, emotional richness demands inclusion of assessments beyond just a positive and negative dimension (e.g., assessing specific emotions like anger, fear and happiness). The present study investigated different properties of autobiographical remembering as a function of discrete emotions and age. Thirty-two younger and thirty-one older adults participated by recalling recent and remote memories associated with six emotional categories and completed the Memory Characteristics Questionnaire for each. Results demonstrated that older adults' angry memories received lower ratings on some phenomenological properties than other emotional memories whereas younger adults' angry memories did not show this same pattern. These results are discussed within the context of socioemotional selectivity theory.     

Aging and attentional guidance during visual search: functional neuroanatomy by positron emission tomography

Positron emission tomography (PET) was used to examine adult age differences in neural activation during visual search. Target detection was less accurate for older adults than for younger adults, but both age groups were successful in using color to guide attention to a subset of display items. Increasing perceptual difficulty led to greater activation of occipitotemporal cortex for younger adults than for older adults, apparently as the result of older adults maintaining higher levels of activation within the easier task conditions. The results suggest that compensation for age-related decline in the efficiency of occipitotemporal cortical functioning was implemented by changes in the relative level of activation within this visual processing pathway, rather than by the recruitment of other cortical regions.     

How does context affect assessments of facial emotion? The role of culture and age

People from Asian cultures are more influenced by context in their visual processing than people from Western cultures. In this study, we examined how these cultural differences in context processing affect how people interpret facial emotions. We found that younger Koreans were more influenced than younger Americans by emotional background pictures when rating the emotion of a central face, especially those younger Koreans with low self-rated stress. In contrast, among older adults, neither Koreans nor Americans showed significant influences of context in their face emotion ratings. These findings suggest that cultural differences in reliance on context to interpret others' emotions depend on perceptual integration processes that decline with age, leading to fewer cultural differences in perception among older adults than among younger adults. Furthermore, when asked to recall the background pictures, younger participants recalled more negative pictures than positive pictures, whereas older participants recalled similar numbers of positive and negative pictures. These age differences in the valence of memory were consistent across culture.     

The specificity of age-related decline in interpretation of emotion cues from prosody

Older adults are not as good as younger adults at decoding prosodic emotions. We sought to determine the specificity of this finding. Performance of older and younger adults was compared on a prosodic emotion task, a "pure" prosodic emotion task, a linguistic prosody task, and a "pure" linguistic prosody task. Older adults were less accurate at interpreting prosodic emotion cues and nonemotional contours, concurrent semantic processing worsened interpretation, and performance was further degraded when identifying negative emotions and questions. Older adults display a pervasive problem interpreting prosodic cues, but further study is required to clarify the stage at which performance declines.     

Compensatory processing during rule-based category learning in older adults

Healthy older adults typically perform worse than younger adults at rule-based category learning, but better than patients with Alzheimer’s or Parkinson’s disease. To further investigate aging’s effect on rule-based category learning, we monitored event-related potentials (ERPs) while younger and neuropsychologically typical older adults performed a visual category-learning task with a rule-based category structure and trial-by-trial feedback. Using these procedures, we previously identified ERPs sensitive to categorization strategy and accuracy in young participants. In addition, previous studies have demonstrated the importance of neural processing in the prefrontal cortex and the medial temporal lobe for this task. In this study, older adults showed lower accuracy and longer response times than younger adults, but there were two distinct subgroups of older adults. One subgroup showed near-chance performance throughout the procedure, never categorizing accurately. The other subgroup reached asymptotic accuracy that was equivalent to that in younger adults, although they categorized more slowly. These two subgroups were further distinguished via ERPs. Consistent with the compensation theory of cognitive aging, older adults who successfully learned showed larger frontal ERPs when compared with younger adults. Recruitment of prefrontal resources may have improved performance while slowing response times. Additionally, correlations of feedback-locked P300 amplitudes with category-learning accuracy differentiated successful younger and older adults. Overall, the results suggest that the ability to adapt one’s behavior in response to feedback during learning varies across older individuals, and that the failure of some to adapt their behavior may reflect inadequate engagement of prefrontal cortex.     

Age differences in vocal emotion perception: on the role of speaker age and listener sex

Older adults have greater difficulty than younger adults perceiving vocal emotions. To better characterise this effect, we explored its relation to age differences in sensory, cognitive and emotional functioning. Additionally, we examined the role of speaker age and listener sex. Participants (N?=?163) aged 19–34 years and 60–85 years categorised neutral sentences spoken by ten younger and ten older speakers with a happy, neutral, sad, or angry voice. Acoustic analyses indicated that expressions from younger and older speakers denoted the intended emotion with similar accuracy. As expected, younger participants outperformed older participants and this effect was statistically mediated by an age-related decline in both optimism and working-memory. Additionally, age differences in emotion perception were larger for younger as compared to older speakers and a better perception of younger as compared to older speakers was greater in younger as compared to older participants. Last, a female perception benefit was less pervasive in the older than the younger group. Together, these findings suggest that the role of age for emotion perception is multi-faceted. It is linked to emotional and cognitive change, to processing biases that benefit young and own-age expressions, and to the different aptitudes of women and men.     

Dual-task processing in younger and older adults: similarities and differences revealed by fMRI

fMRI was used to explore age differences in the neural substrate of dual-task processing. Brain activations when there was a 100 ms SOA between tasks, and task overlap was high, were contrasted with activations when there was a 1000 ms SOA, and first task processing was largely complete before the second task began. Younger adults (M=21 yrs) showed activation in dorsolateral prefrontal cortex and in parietal areas as well as in ventral medial frontal cortex and sub-lobar areas. Activations in older adults (M=71 yrs) did not differ significantly from younger adults except for higher activations in occipital and polar prefrontal cortex. The results were well fit by a model with two networks managing dual-task interference, a medial prefrontal network that detects changes in the stimulus situation and maps them to associated changes in the valence of response mappings and a lateral frontal-parietal network that initiates and carries out the shift from one task to the other. The additional activations in older adults as a group and the correlations of individual differences in activation with performance were consistent with recruitment within each of these networks. Alternative explanations such as hemispheric asymmetry reduction and reactive rather than proactive processing in older adults were not supported.     

Posterior P1 and early frontal negativity reflect developmental changes in attentional distraction during adolescence

Previous studies in adults have revealed that attentional distraction modulates the late positive potential (LPP) during emotion regulation. To determine whether early visual components reflect developmental changes in attentional distraction during adolescence, we collected event-related potentials from 20 young adolescents, 18 older adolescents, and 18 young adults as they performed a distraction task (counting) while viewing affective images. Consistent with previous findings obtained in distraction studies, the distraction task (counting) reduced emotional modulation of the LPP. At an early stage of processing, counting reduced emotional modulation of P1 and increased the negativity bias of early frontal negativity (eFN) for negatively valenced pictures compared to simple viewing with no distraction. sLORETA analyses further revealed eFN indexing of rostral prefrontal cortical activation, a cortical area that has been shown in recent fMRI studies to be activated by distraction. Moreover, P1 amplitudes in young and older adolescents did not differ but were both larger than the P1s in young adults. In addition, eFN amplitudes significantly decreased with age. The dissociable distraction patterns between the posterior P1 and eFN provide evidence not only for the timing hypothesis of emotion regulation but also for different developmental trajectories of visual processing areas and the prefrontal cortex during affective processing in adolescence.     

Emotion experience and expression across the adult life span: insights from a multimodal assessment study

This investigation represents a multimodal study of age-related differences in experienced and expressed affect and in emotion regulatory skills in a sample of young, middle-aged, and older adults (N=96), testing formulations derived from differential emotions theory. The experimental session consisted of a 10-min anger induction and a 10-min sadness induction using a relived emotion task; participants were also randomly assigned to an inhibition or noninhibition condition. In addition to subjective ratings of emotional experience provided by participants, their facial behavior was coded using an objective facial affect coding system; a content analysis also was applied to the emotion narratives. Separate repeated measures analyses of variance applied to each emotion domain indicated age differences in the co-occurrence of negative emotions and co-occurrence of positive and negative emotions across domains, thus extending the finding of emotion heterogeneity or complexity in emotion experience to facial behavior and verbal narratives. The authors also found that the inhibition condition resulted in a different pattern of results in the older versus middle-aged and younger adults. The intensity and frequency of discrete emotions were similar across age groups, with a few exceptions. Overall, the findings were generally consistent with differential emotions theory.     

老年人日常人际问题解决中的悲伤情绪体验和情绪调节策略: 年龄和人格特质的作用

考察了日常人际问题解决中老年人的悲伤情绪体验和情绪调节策略与青年人的差异,以及年龄和人格特质的作用。共45名老年人和59名青年人接受半结构化访谈和人格特质测量。结果表明：（1）以教育水平为协变量的方差分析表明,老年人和青年人的悲伤情绪体验没有显著差异。老年人的被动情绪调节策略的使用和青年人存在显著差异;（2）老年人的被动情绪调节策略不但与年龄有关,而且与悲伤情绪体验有关。悲伤情绪体验可以显著预测其被动情绪调节策略使用;（3）老年人的悲伤情绪体验与人格特质神经质维度存在显著正相关;（4）老年人与年轻人的被动情绪调节策略都与悲伤情绪有关,但老年人的被动情绪调节策略不能由人格特质显著预测,而青年人的被动调节策略还可以由人格特质内外向维度显著预测。人格特质的内外向维度对老年人和青年人的前摄性情绪调节策略的预测效应是一致的。最后针对老年人的悲伤情绪体验和情绪调节策略的意义进行了讨论。