面部表情的阈下情绪启动效应及其机制

人类大脑是否可以加工阈下情绪信息?阈下情绪启动效应为此提供了直接证据。使用视觉掩蔽和连续闪烁抑制范式,以面部表情作为启动刺激的研究发现,个体在注意和记忆、社会性评价和行为倾向中都受先前启动刺激情绪属性的影响,即表现出了阈下情绪启动效应。还有研究发现,阈下面部表情增强了个体的皮肤电导水平和心血管系统反应。而神经机制的研究发现,阈下面部表情对目标刺激的早期知觉加工和晚期情绪意义分析产生了影响,杏仁核等脑区在其中具有重要作用。情绪优先假设和感受即信息理论分别从情绪系统领域特殊性和情绪归因的角度试图阐释该效应产生的机制。在总结和分析以往研究基础上,本文对这一领域的未来研究提出了具体建议。     

雌激素对情绪的影响：心理、神经、内分泌研究

雌激素通过复杂的生理和心理学机制对中枢神经系统施加影响.生理学方面包括：雌激素在杏仁核、海马和前额叶等这些与情绪认知相关的重要脑区内影响神经递质的产生和效能;雌激素可以作用于下丘脑-垂体-肾上腺轴,改变情绪性行为;雌激素受体的基因转录也可以调节情绪性行为的变化.雌激素也通过神经心理学的因素影响情绪加工：雌激素可以提高情绪编码技能,提升表情识别的准确性;雌激素能够影响情绪的唤醒,改变个体情绪体验的强度.未来的研究要融合心理、神经和内分泌等各种因素,以解决女性情绪障碍这一难题.     

情绪调节时间知觉的作用方式及认知神经机制

人类的时间知觉会受到情绪的调节发生主观扭曲,这种调节可以通过情绪的体验与预期来实现.本文区分了体验性情绪和预期性情绪调节时间知觉的作用方式和认知机制,基于标量计时理论,提出了在不同加工阶段情绪调节时间知觉的认知理论模型,并梳理了情绪调节时间知觉的神经生理学基础和脑机制方面的证据.未来研究需更关注预期性情绪对时间知觉的调节作用,考察注意、唤醒和效价等因素的交互影响,并进一步探究情绪调节时间知觉的神经机制.     

肌内注射肉毒素后脊髓运动神经元电生理特性的变化

注射肉毒素(A 型)于成年猫一侧的内侧头腓肠肌、外侧头腓肠肌和比目鱼肮内,功能性地阻断这些肌肉与神经的联系。注射肉毒素约三星期后,用细胞内记录技术观察一侧被注射肉毒素肌肉(简称肉毒侧)的运动神经元电生理特性的变化,主要结果如下:(1)与正常动物的或一侧肌内注射肉毒素动物的对侧运动神经元比较,肉毒侧极大多数运动神经元的后超极化电位时程明显减短,动作电位上升相的弯折不明显,动作电位时程减短;并且这运动神经元在通较弱电流时就产生重复发放。(2)给二个逆向刺激时,肉毒侧的极大多数运动神经元在较短的刺激间隔时间就出现第二个 SD 峰电位。(3)肉毒侧运动神经元的静息电位、神经轴突传导速度及动作电位超射均无异常。第三项中的结果与切断轴突后的结果不同。肉毒侧内侧头腓肠肌、外侧头腓肠肌和比目鱼肌运动神经元的后超极化电位时程都减短的结果与切断轴突、横切脊髓或河豚毒阻断神经冲动使肌肉不活动后的结果也不同,后两者仅使比目鱼肌运动神经元的后超极化电位时程减短。最后讨论了产生这些结果的可能机制,它需要进一步进行研究。     

自尊研究综述

自尊是一个系统,它不仅涉及了个体的认知层面,还包括个体的情感层面,并且根据个体所处的特定的情景,其表现有时稳定,有时不稳定。自尊的情感模型主要探讨了自尊的组成成分与自尊的起源;自尊的认知模型把自尊看成个体对自己作为人的价值的有意识判断;以恐惧管理理论为代表的自尊的社会学模型又从新的角度解释了自尊的理论模型。罗森伯格的自尊量表开启了自尊测量的先河,我国学者在自尊的测量方面也取得了相应的进展。同时,从社会比较理论与评价性反馈两个角度阐述了自尊的作用。自尊的研究遍布群体从幼儿、青少年到大学生,都有丰富的实证研究。自尊结构的研究领域内出现了一些新进展,主要表现在内隐自尊、具体自尊及集体自尊研究的逐步兴起。     

负性情绪加工与体验以相反方式影响冲突适应

情绪和认知控制的相互影响塑造着我们的行为.冲突适应反映了认知控制的两个关键加工(监测冲突和控制冲突),因此调查情绪对冲突适应的影响有助于说明情绪与认知控制相互作用的基本机制.不过,已有研究在负性情绪如何影响冲突适应的问题得到了矛盾的结果:有研究发现负性情绪抑制了冲突适应;有研究发现负性情绪易化了冲突适应.值得注意的是,在冲突适应受到抑制的研究中,负性情绪是通过在认知任务中插入图片临时诱发的,而在冲突适应受到易化的研究中,负性情绪是在实验前诱发并在实验中持续存在的.据此推测,抑制冲突适应的负性情绪带有更多情绪加工的成分,而易化冲突适应的负性情绪带有更多的情绪体验成分.本研究采用插入情绪图片来诱发负性情绪,但将情绪诱发分为早期组块(此时被试对情绪材料没有形成习惯化反应,情绪加工占主导地位)和晚期组块(此时被试对情绪材料已经形成习惯化反应,情绪体验占主导地位)进行分析.与本课题组的预期相符,早期组块中冲突适应受到抑制,晚期组块中冲突适应受到易化.因此,本研究解决了已有研究间的分歧,说明冲突适应之所以受到抑制是因为受到负性情绪加工的影响,而冲突适应之所以受到易化是因为受到负性情绪体验的影响.本课题组进一步提出,负性情绪加工可能是通过占用认知资源抑制冲突适应的,而负性情绪体验可能是通过提升警觉水平而易化冲突适应的.本研究也凸显了任务配置在冲突适应中的重要性,加深了对冲突适应产生机制的理解.     

自尊研究综述

自尊是一个系统,它不仅涉及了个体的认知层面,还包括个体的情感层面,并且根据个体所处的特定的情景,其表现有时稳定,有时不稳定。自尊的情感模型主要探讨了自尊的组成成分与自尊的起源;自尊的认知模型把自尊看成个体对自己作为人的价值的有意识判断;以恐惧管理理论为代表的自尊的社会学模型又从新的角度解释了自尊的理论模型。罗森伯格的自尊量表开启了自尊测量的先河,我国学者在自尊的测量方面也取得了相应的进展。同时,从社会比较理论与评价性反馈两个角度阐述了自尊的作用。自尊的研究遍布群体从幼儿、青少年到大学生,都有丰富的实证研究。自尊结构的研究领域内出现了一些新进展,主要表现在内隐自尊、具体自尊及集体自尊研究的逐步兴起。     

情绪对时间知觉的影响及其神经生理学机制

时间在人们的认知过程中发挥着重要的作用。个体对于时间的感知一直是神经科学领域以及心理学领域关心的话题。一些研究表明,人们对时间的体验受情绪的影响。早期的相关研究主要集中在心理学领域。近年来,时间知觉的神经生理学机制研究取得了较多的进展,这使得研究者们能够从神经网络机制,神经递质变化以及突触可塑性等角度探索情绪如何调节时间知觉。本文对近年来有关情绪影响时间知觉的相关研究进行综述,以期为深入探索时间知觉的神经机制提供帮助。     

情绪的脑机制研究在社会认知神经科学中的进展

社会认知神经科学是近几年国外新兴起的交叉学科,旨在阐述社会性、情绪性的体验与行为的心理和神经基础。它综合了认知神经科学与社会心理学研究的长处,对刻板印象、态度与态度改变、他人知觉、自我认知以及情绪与认知交互作用等方面进行了深入研究。主要范式是应用认知神经科学的方法来验证社会心理学在这些范畴上的各种不同理论观点,并在某些方面取得了突破性进展,但仍存在着广泛的发展空间。随着当前各种脑成像技术的革新,人们对情绪状态下大脑的神经活动的了解在原来认知的层面上有了进一步提升。本文主要阐述社会认知神经科学在情绪的脑机制研究上所取得的进展。     

人类的利他性惩罚：认知神经科学的视角

利他性惩罚广泛存在于人类社会中,在群体合作与规范维护方面起着重要的积极作用．个体作为潜在的惩罚者,从知觉到不公平事件到做出惩罚行为,需要经过一系列的认知和情绪过程,包括公平判断、奖赏加工、自我控制以及心理化等过程,并且调用相应的神经生理机制．认知神经科学为理解人类的利他性惩罚行为提供了新的视角和方法．本文基于最新的研究发现,综述了利他性惩罚相关的神经生理基础．     

The face is not an empty canvas: how facial expressions interact with facial appearance

Faces are not simply blank canvases upon which facial expressions write their emotional messages. In fact, facial appearance and facial movement are both important social signalling systems in their own right. We here provide multiple lines of evidence for the notion that the social signals derived from facial appearance on the one hand and facial movement on the other interact in a complex manner, sometimes reinforcing and sometimes contradicting one another. Faces provide information on who a person is. Sex, age, ethnicity, personality and other characteristics that can define a person and the social group the person belongs to can all be derived from the face alone. The present article argues that faces interact with the perception of emotion expressions because this information informs a decoder''s expectations regarding an expresser''s probable emotional reactions. Facial appearance also interacts more directly with the interpretation of facial movement because some of the features that are used to derive personality or sex information are also features that closely resemble certain emotional expressions, thereby enhancing or diluting the perceived strength of particular expressions.     

The masculinity paradox: facial masculinity and beardedness interact to determine women's ratings of men's facial attractiveness

In many species, male secondary sexual traits have evolved via female choice as they confer indirect (i.e. genetic) benefits or direct benefits such as enhanced fertility or survival. In humans, the role of men's characteristically masculine androgen‐dependent facial traits in determining men's attractiveness has presented an enduring paradox in studies of human mate preferences. Male‐typical facial features such as a pronounced brow ridge and a more robust jawline may signal underlying health, whereas beards may signal men's age and masculine social dominance. However, masculine faces are judged as more attractive for short‐term relationships over less masculine faces, whereas beards are judged as more attractive than clean‐shaven faces for long‐term relationships. Why such divergent effects occur between preferences for two sexually dimorphic traits remains unresolved. In this study, we used computer graphic manipulation to morph male faces varying in facial hair from clean‐shaven, light stubble, heavy stubble and full beards to appear more (+25% and +50%) or less (?25% and ?50%) masculine. Women (N = 8520) were assigned to treatments wherein they rated these stimuli for physical attractiveness in general, for a short‐term liaison or a long‐term relationship. Results showed a significant interaction between beardedness and masculinity on attractiveness ratings. Masculinized and, to an even greater extent, feminized faces were less attractive than unmanipulated faces when all were clean‐shaven, and stubble and beards dampened the polarizing effects of extreme masculinity and femininity. Relationship context also had effects on ratings, with facial hair enhancing long‐term, and not short‐term, attractiveness. Effects of facial masculinization appear to have been due to small differences in the relative attractiveness of each masculinity level under the three treatment conditions and not to any change in the order of their attractiveness. Our findings suggest that beardedness may be attractive when judging long‐term relationships as a signal of intrasexual formidability and the potential to provide direct benefits to females. More generally, our results hint at a divergence of signalling function, which may result in a subtle trade‐off in women's preferences, for two highly sexually dimorphic androgen‐dependent facial traits.     

The causes and consequences of maxillofacial injuries in elderly people

Objective: The occurrence of trauma in older people is well‐documented; however the incidence of maxillofacial trauma is scarcely reported. Therefore, the objective of this study is to determine the causes and consequences of maxillofacial trauma in older people. Design: A five‐year (March 95 ‐ March 2000) retrospective study was earned out of all patients over the age of 65 years with facial trauma presenting to Accident and Emergency Department (A&E). The information was collected using the medical notes and discharge summaries. Setting: The Departments of A&E and Maxillofacial Surgery. Subjects: A total of 42 patients' records were examined for study related data. Results: A total of 42 patients were seen during the study period. Thirty‐six gave a history of a fall, of which 15 had tripped, 5 had slipped, 3 resulted from a Transient Ischaemic Attack (TIA), 1 as a result of alcohol abuse, in 1 a prosthetic knee gave way and 11 gave no cause for the fall. Of the remaining 6 patients. 5 were assaulted and 1 had a wardrobe fall on top of him. The majority of the falls occurred during the winter months. Maxillofacial injuries were noted in 27 of the 42 patients. Sixteen patients had cheekbone fractures, 8 mandibular fractures, 2 midface and 1 orbital complex fracture. Twenty‐five percent of cheekbone fractures and 50% of mandibular fractures were treated surgically. Medical history was noted in 27 patients. Conclusions: This study clearly demonstrates the majority of the facial trauma in the older people can be treated conservatively unless the patients complain of functional problems.     

The dynamics of production and destruction: Analytic insight into complex behavior

This paper analytically explores the properties of simple differential-difference equations that represent dynamic processes with feedback dependent on prior states of the system. Systems with pure negative and positive feedback are examined, as well as those with mixed (positive/negative) feedback characteristics. Very complex time dependent behaviors may arise from these processes. Indeed, the same mechanism may, depending on system parameters and initial conditions, produce simple, regular, repetitive patterns and completely irregular random-like fluctuations.For the differential-delay equations considered here we prove the existence of: (i) stable and unstable limit cycles, where the stable cycles may have an arbitrary number of extrema per period; and (ii) chaos, meaning the presence of infinitely many periodic solutions of different period and of infinitely many irregular and mixing solutions.     

Congenital facial palsy and emotion processing: The case of Moebius syndrome

According to the Darwinian perspective, facial expressions of emotions evolved to quickly communicate emotional states and would serve adaptive functions that promote social interactions. Embodied cognition theories suggest that we understand others' emotions by reproducing the perceived expression in our own facial musculature (facial mimicry) and the mere observation of a facial expression can evoke the corresponding emotion in the perceivers. Consequently, the inability to form facial expressions would affect the experience of emotional understanding. In this review, we aimed at providing account on the link between the lack of emotion production and the mechanisms of emotion processing. We address this issue by taking into account Moebius syndrome, a rare neurological disorder that primarily affects the muscles controlling facial expressions. Individuals with Moebius syndrome are born with facial paralysis and inability to form facial expressions. This makes them the ideal population to study whether facial mimicry is necessary for emotion understanding. Here, we discuss behavioral ambiguous/mixed results on emotion recognition deficits in Moebius syndrome suggesting the need to investigate further aspects of emotional processing such as the physiological responses associated with the emotional experience during developmental age.     

The cost of fluctuating inbreeding depression

We present a phenotypic model for the evolution of self-fertilization in an infinite population of annual hermaphrodites for the case in which fitness and inbreeding depression vary among generations (e.g., due to fluctuations in the environment from year to year). Conditions for the evolution of selfing, mixed mating, and outcrossing are derived and are compared with results from numerical calculations that assume a normal distribution of inbreeding depression. In contrast to the situation in which inbreeding depression does not vary, when inbreeding depression fluctuates in a stochastic manner among generations with a mean less than 0.5, selfing is not necessarily selected. Thus, fluctuating inbreeding depression can be viewed as an additional cost of selfing that may stabilize mixed mating systems. These results emphasize the need to take into account fluctuating inbreeding depression in empirical studies aimed at understanding mating system evolution in annuals.     

Evidence for adaptive design in human gaze preference

Many studies have investigated the physical cues that influence face preferences. By contrast, relatively few studies have investigated the effects of facial cues to the direction and valence of others' social interest (i.e. gaze direction and facial expressions) on face preferences. Here we found that participants demonstrated stronger preferences for direct gaze when judging the attractiveness of happy faces than that of disgusted faces, and that this effect of expression on the strength of attraction to direct gaze was particularly pronounced for judgements of opposite-sex faces (study 1). By contrast, no such opposite-sex bias in preferences for direct gaze was observed when participants judged the same faces for likeability (study 2). Collectively, these findings for a context-sensitive opposite-sex bias in preferences for perceiver-directed smiles, but not perceiver-directed disgust, suggest gaze preference functions, at least in part, to facilitate efficient allocation of mating effort, and evince adaptive design in the perceptual mechanisms that underpin face preferences.     

Indirect vegetation–soil moisture feedback with application to Holocene North Africa climate1

Using a fully coupled climate–terrestrial ecosystem model, we demonstrate explicitly that an initial perturbation on vegetation induces not only a direct positive vegetation feedback, but also a significant indirect vegetation–soil moisture feedback. The indirect feedback is generated through either fractional cover change or soil moisture depletion. Both indirect feedback mechanisms are triggered by a vegetation perturbation, but involve subsequent effects of soil moisture and evaporation, indirectly. An increase in vegetation tends to reduce bare‐ground evaporation through either the area reduction in bare ground or the depletion of soil moisture; the reduced evaporation may then counter the initial plant transpiration, favoring a negative net vegetation feedback. Furthermore, grasses are more effective in inducing the indirect vegetation–soil feedbacks, because of their limited plant evapotranspiration and shallower roots that tend to change surface soil moisture, and, in turn, evaporation, effectively. In comparison, trees favor a direct positive vegetation feedback due to their strong plant transpiration on subsurface soil moisture as well as a lower albedo.     

An interspecific analysis of relative jaw‐joint height in primates

Jaw‐joint height (JJH) above the occlusal plane is thought to be influenced by cranial base angle (CBA) and facial angulation during growth. To better understand how JJH relates to midline craniofacial form, we test the hypothesis that relative increases in JJH are correlated with increasing CBA flexion and facial kyphosis (i.e., ventral bending) across primates. We compared JJH above the occlusal plane to CBA and the angle of facial kyphosis (AFK) across adults from 82 species. JJH scales with positive allometry relative to a skull geometric mean in anthropoids and most likely strepsirrhines. Anthropoid regressions for JJH are elevated above strepsirrhines, whereas catarrhines exhibit a higher slope than platyrrhines. Semipartial correlations between relative JJH and both CBA and AFK show no association across a small strepsirrhine sample, limited associations among catarrhines and anthropoids, but strong correlations in platyrrhines. Contrary to our hypothesis, however, increases in relative JJH are correlated with relatively less flexed basicrania and more airorhynch faces (i.e., reduced ventral bending) in platyrrhines. The mosaic pattern of relationships involving JJH across primate clades points to multiple influences on JJH across primates. In clades showing little association with basicranial and facial angles, such as strepsirrhines, the potential morphological independence of JJH may facilitate a relative freedom for evolutionary changes related to masticatory function. Finally, failure to associate relative JJH and basicranial flexion in most clades suggests that the relatively taller JJH and more flexed basicrania of anthropoids compared to strepsirrhines may have evolved as an isolated event during the origin of anthropoids. Am J Phys Anthropol 142:519–530, 2010. © 2010 Wiley‐Liss, Inc.