【作者】 罗扬眉；

【导师】 黄希庭；

【作者基本信息】 西南大学 ， 基础心理学， 2014， 博士

【摘要】 幸福是每个个体的内在需要和核心动力,也是全人类的共同目标和共同主题。在东方,我国最古老的文献之一《易经》就有追求幸福的表述。在西方,古希腊贤哲们也对幸福有着深刻的理论思考。到现代,随着实证科学的发展,幸福已经成为了哲学、伦理学、心理学、社会学、教育学、经济学、人类学和神经科学等多学科炙手可热的研究问题之一。特别是在心理学中,研究者们对影响幸福感的主客观因素进行了大量研究,增进了人们对幸福感的理解。大脑是幸福感的产生、维持和变化的重要生理基础。随着现代脑成像技术的发展和成熟,人们对幸福感与大脑的关系问题有着越来越浓厚的兴趣。然而,目前对幸福感的神经机制研究还相对较少,幸福感是如何反映在大脑中的还不是很清楚。对幸福与大脑关系的研究,能够有效地识别幸福的神经生物学标签,有助于人类更加全面地理解幸福感的生物基础,其理论意义和实践价值是不言而喻的。鉴于理解幸福感和大脑关系的重要性,我们对幸福的神经机制展开了研究。为了便于研究,本研究将幸福界定为特质幸福,即一段较长时期内的幸福感。本研究采用磁共振成像技术,从多模态神经成像的视角,即结构态、静息态和任务态,对幸福与大脑结构和功能的关系进行了全面而系统地探索。首先,当前对幸福感神经机制的研究大多将幸福感这一复杂结构简单还原为愉悦感。而且,可能由于方法学上的局限性,很少有研究探索特质幸福感的神经机制。基于此,研究一采用结构模态中基于体素的形态学技术和静息态中的局部一致性和功能连接技术,通过3个实验来探讨总体特质幸福感与大脑结构和功能的关系。在研究一中,采用幸福感量表(Subjective Happiness Scale来测量幸福。实验1对169名健康大学生被试的大脑灰质体积进行基于体素的形态学分析。实验2是采用局部一致性的指标对高低幸福组各25名健康大学生被试的静息态进行分析。实验3是采用静息态功能连接的指标对实验2的数据进行进一步分析。总的结果发现,大脑的前额叶,颞叶、顶叶,边缘系统以及部分皮层下区域的结构和功能与总体幸福感有关,而这些区域大多位于默认网络、情绪和奖赏网络和执行控制网络等大脑网络系统。这一结果表明了总体幸福感与个体的自我评价和反思、集中注意力于当下、回忆过去和想象将来的能力,情绪体验和奖赏加工的能力,以及认知控制和执行功能的能力有关。其次,由于起源于截然不同的哲学观,特质幸福可以分成追求快乐避免痛苦的快乐论幸福与追求意义和自我实现的实现论幸福。对于快乐论幸福感与实现论幸福感在大脑的结构和功能上是否有一致表征,目前还不清楚。因此,研究二也采用了结构态中的基于体素的形态学技术和静息态中的功能连接技术,对快乐论幸福感和实现论幸福感各自的神经基础进行了研究。在研究二中,与过去研究一致,快乐论幸福是用积极和消极情感量表(Positive and Negative Affect Schedule, PANAS)中的积极情感分量表来测量的；而实现论幸福是用心理幸福感量表(Scalesof Psychological Well-Being, PWB)来测量的。实验4对124名健康大学生被试的大脑结构像的灰质体积进行了基于体素的形态学分析。实验5是采用功能连接技术对118名大学被试的静息态数据进行了分析。总的结果发现,快乐论幸福和实现论幸福在行为上有较高的相关性(rs>0.32,p<0.001)。它们分别与大脑结构和功能上既有类似的神经基础,但也存在一定的差异。具体地说来,在共同性上,默认网络(Default Mode Network, DMN)与右侧背外侧前额皮层(dorsolateral prefrontal cortex, DLPFC)的功能连接强度越负性,与右侧的额内侧回上部(Superior Medial Frontal Gyrus, sMFG)的功能连接强度越强,快乐论幸福和实现论幸福程度越高。在差异上,默认网络和颞叶、顶叶等区域的功能连接与快乐论幸福相关,而默认网络和前额皮层、小脑等区域的功能连接与实现论幸福相关。并且,快乐论幸福与颞中回的灰质体积有正相关关系,而实现论幸福与顶下沟的灰质体积有正相关关系。总的来说,快乐论幸福和实现论性在神经基础上的共同性和差异,说明了它们两者都对幸福有着重要的作用,共同促进幸福。最后,从时间心理学的角度出发,可以将对刺激的心理加工分成期待和体验两个阶段。期待就是刺激还没有到来时的心理状态,而体验主要是指对当前刺激的心理加工。目前大多数研究均集中在对特质幸福个体情绪体验加工阶段的神经机制,而很少关注特质幸福个体情绪期待加工。将来期待是趋向动机,它对心理健康和幸福有着重要的作用。因此,研究三采用基于任务的功能磁共振技术,探讨了特质幸福个体对将来期待影响的神经机制。让40名大学生被试执行情绪期待任务,同时扫描他们在期待将来积极或中性事件时的大脑活动。结果发现,双侧的内侧前额皮层(medial prefrontal cortex,MPFC)在期待将来积极事件比期待将来中性事件时有更大的激活,并且这种激活能够预测个体特质幸福感的水平。这一结果表明对追求将来积极事件的动机对于幸福感有着重要的作用。本研究采用了多种磁共振成像技术和方法,较为全方面地探讨幸福的神经机制,为丰富和发展幸福的理论提供神经科学视角,也为发展出提高个体幸福感水平的有效干预方法提供了神经科学证据。但是,这个领域还有许多问题需要进—步探索。例如,不同文化背景下人们的幸福感与大脑的关系是否是相同的；总体特质幸福与领域幸福脑机制有着怎样的关系；大脑和幸福有着怎样的因果关系等等。这些也是我们今后的研究任务。更多还原

【Abstract】 Happiness is the intrinsic need and motivation of individual. It is also the common goal and the common theme of all mankind. In eastern, there are statements on happiness in one of the oldest classic "1Ching: Book of Changes" in China. In western, philosophers in Greek times had deliberated over happiness and developed the profound theories.Nowadays, with the development of empirical research, happiness has been of considerable interest in philosophy, ethics, psychology, sociology, education, economics, anthropology and neuroscience. In psychology, a wealth of research has examined the associations between happiness and a host of diverse subjective and objective factors. The findings enhance people’s understanding of happiness.The brain plays an important role in emergence, maintenance and promotion of happiness. With the development of neuroimaging technique, there is growing interest on neural correlates of happiness. However, limited work has examined the relationship between the brain and happiness and less is known how happiness is reflected in the brain. Studying the neural basis of happiness, will effectively identify the neural markers of happiness and will provide neuroscientific evidence to enhance our knowledge on happiness, which is of great value in the theory and the practice.Given the importance of understanding the relationship between happiness and the brain, we examined the neural mechanisms of happiness. Following previous studies, happiness characterizes individuals’characteristic level of happiness during a particular period of time. From the perspective of multimodal neuroimaging, the current study used the structural magnetic resonance imaging (MRI), resting-state and task-based functional MRI (fMRI) to investigate systematically how trait happiness is reflected in brain structure and function.Few studies were conducted on trait happiness within a neuroscientific framework. Furthermore, most of current neuroscientific studies simply reduced happiness to pleasure. Thus, the study one firstly investigated the neural basis of overall happiness, by conducting three experiments using voxel-based morphometry (VBM) techniques in MRI, and Regional homogeneity (ReHo) and functional connectivity (FC) in the resting-state fMRI, respectively. In this study, happiness was measured by Subjective Happiness Scale (SHS).In experiment one, the structural MR images from169young, healthy adults were analyzed by VBM. In experiment two, regional homogeneity (ReHo) in resting-state fMRI was examined on two groups of young adults:happy and unhappy individuals (N=25per group). In experiment three, functional connectivity (FC) in resting-state fMRI was further examined on data from experiment two. The results showed that the structure and function of the prefrontal cortex, temporal lobe, parietal lobe, the limbic system and the subcortical structures were related to the overall happiness. Importantly, these areas are mostly overlap with the default network, the emotion and reward networks, and executive control network. These findings may indicate that overall happiness were related to people’s self-evaluation, self-reflection, past memories, future imagination, ability to process emotional experiences and rewards, as well as the executive function.Secondly, due to the distinct philosophy, happiness can be divided into hedonic happiness (pleasure attainment and pain avoidance) and eudaimonic happiness (meaning and self-realization). However, less is known how hedonic happiness and eudaimonic happiness are reflected in the brain and their similarities and differences. Therefore, the study two also used VBM in structural MRI and FC in resting-state fMRI to investigate the neural correlates of hedonic happiness and eudaimonic happiness, respectively. Following with previous studies, hedonic happiness was measured by positive affect sub-scales of Positive and Negative Affect Schedule (PANAS), while eudaimonic happiness was measured by Scales of Psychological Well-Being (PWB). In experiment four, the structural MR images from124young, healthy adults were analyzed by VBM. In experiment five, functional connectivity (FC) in resting-state fMRI from118young adults was examined. The results demonstrated that hedonic happiness and eudaimonic happiness have significant correlation (rs>0.32, p<0.001). However, the neural correlates of hedonic happiness and eudaimonic happiness shared some common characteristics and also are different from each other. Specifically, the decreased functional connectivity between Default Mode Network (DMN) and dorsolateral prefrontal cortex (DLPFC), and the increased functional connectivity between DMN and Superior Medial Frontal Gyrus (sMFG) correlated with hedonic happiness and eudaimonic happiness. The functional connectivity between DMN and some regions in temporal lobe and parietal lobe correlated with hedonic happiness, while the functional connectivity between DMN and some regions in prefrontal cortex and cerebellum correlated with eudaimonic happiness. Furthermore, hedonic happiness was positively associated with right middle temporal gyrus gray matter volume, while eudaimonic happiness was positively associated with inferior parietal lobule gray matter volume. Taken together, the similarities and differences between hedonic happiness and eudaimonic happiness may suggest they play different roles and work together to promote the overall happiness.Finally, from the perspective of time, reward processing can be divided into anticipation and experience. Anticipation represents the psychological state when the stimulus is yet to come, and the experience represents the psychological processing of the current stimulus. Most current research on the neural mechanisms of emotional processing among happy and unhappy individuals focused on the experience. However, anticipation is related to approach motivation, which is important to mental health and happiness. Thus, basing on the tasked-based fMRI, the study three investigated the neural correlates of anticipation as a function of trait happiness.40young adults were instructed to conduct the emotional anticipation task. We scanned the participants’brain activity when they were anticipating future positive or neutral events. It was found that bilateral medial prefrontal cortex (MPFC) was activated when people were anticipating the future positive event rather than the future neutral events. More importantly, the activation in medial prefrontal cortex can predict the level of the individual’s trait happiness. These findings may suggest that the approach motivation for the future positive events plays a key role in trait happiness.These studies used a variety of neuroimaging techniques and methods to investigate the neural correlates of happiness. These findings may provide neuroscientific insight into the development of the happiness theories, and give neuroscientific evidence to develop intervention practices on individual’s happiness. However, several limitations and future directions need to be considered. Firstly, the future studies to investigate the happiness in different cultures within neuroscience framework are needed. Secondly, the neural relationships between overall trait happiness and specific happiness are also needed investigated. Lastly, it will be of merit to addressing the causal relationship between the brain and happiness in future study. These directions are our research tasks in future.更多还原