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。     

Genetic Variations in COMT and DRD2 Modulate Attentional Bias for Affective Facial Expressions

Studies have revealed that catechol-O-methyltransferase (COMT) and dopaminegic receptor2 (DRD2) modulate human attention bias for palatable food or tobacco. However, the existing evidence about the modulations of COMT and DRD2 on attentional bias for facial expressions was still limited. In the study, 650 college students were genotyped with regard to COMT Val158Met and DRD2 TaqI A polymorphisms, and the attentional bias for facial expressions was assessed using the spatial cueing task. The results indicated that COMT Val158Met underpinned the individual difference in attentional bias for negative emotional expressions (P = 0.03) and the Met carriers showed more engagement bias for negative expressions than the Val/Val homozygote. On the contrary, DRD2 TaqIA underpinned the individual difference in attentional bias for positive expressions (P = 0.003) and individuals with TT genotype showed much more engagement bias for positive expressions than the individuals with CC genotype. Moreover, the two genes exerted significant interactions on the engagements for negative and positive expressions (P = 0.046, P = 0.005). These findings suggest that the individual differences in the attentional bias for emotional expressions are partially underpinned by the genetic polymorphisms in COMT and DRD2.     

Women's Greater Ability to Perceive Happy Facial Emotion Automatically: Gender Differences in Affective Priming

There is evidence that women are better in recognizing their own and others' emotions. The female advantage in emotion recognition becomes even more apparent under conditions of rapid stimulus presentation. Affective priming paradigms have been developed to examine empirically whether facial emotion stimuli presented outside of conscious awareness color our impressions. It was observed that masked emotional facial expression has an affect congruent influence on subsequent judgments of neutral stimuli. The aim of the present study was to examine the effect of gender on affective priming based on negative and positive facial expression. In our priming experiment sad, happy, neutral, or no facial expression was briefly presented (for 33 ms) and masked by neutral faces which had to be evaluated. 81 young healthy volunteers (53 women) participated in the study. Subjects had no subjective awareness of emotional primes. Women did not differ from men with regard to age, education, intelligence, trait anxiety, or depressivity. In the whole sample, happy but not sad facial expression elicited valence congruent affective priming. Between-group analyses revealed that women manifested greater affective priming due to happy faces than men. Women seem to have a greater ability to perceive and respond to positive facial emotion at an automatic processing level compared to men. High perceptual sensitivity to minimal social-affective signals may contribute to women's advantage in understanding other persons' emotional states.     

The Influence of a Working Memory Task on Affective Perception of Facial Expressions

In a dual-task paradigm, participants performed a spatial location working memory task and a forced two-choice perceptual decision task (neutral vs. fearful) with gradually morphed emotional faces (neutral ∼ fearful). Task-irrelevant word distractors (negative, neutral, and control) were experimentally manipulated during spatial working memory encoding. We hypothesized that, if affective perception is influenced by concurrent cognitive load using a working memory task, task-irrelevant emotional distractors would bias subsequent perceptual decision-making on ambiguous facial expression. We found that when either neutral or negative emotional words were presented as task-irrelevant working-memory distractors, participants more frequently reported fearful face perception - but only at the higher emotional intensity levels of morphed faces. Also, the affective perception bias due to negative emotional distractors correlated with a decrease in working memory performance. Taken together, our findings suggest that concurrent working memory load by task-irrelevant distractors has an impact on affective perception of facial expressions.     

Involvement of Right STS in Audio-Visual Integration for Affective Speech Demonstrated Using MEG

Speech and emotion perception are dynamic processes in which it may be optimal to integrate synchronous signals emitted from different sources. Studies of audio-visual (AV) perception of neutrally expressed speech demonstrate supra-additive (i.e., where AV>[unimodal auditory+unimodal visual]) responses in left STS to crossmodal speech stimuli. However, emotions are often conveyed simultaneously with speech; through the voice in the form of speech prosody and through the face in the form of facial expression. Previous studies of AV nonverbal emotion integration showed a role for right (rather than left) STS. The current study therefore examined whether the integration of facial and prosodic signals of emotional speech is associated with supra-additive responses in left (cf. results for speech integration) or right (due to emotional content) STS. As emotional displays are sometimes difficult to interpret, we also examined whether supra-additive responses were affected by emotional incongruence (i.e., ambiguity). Using magnetoencephalography, we continuously recorded eighteen participants as they viewed and heard AV congruent emotional and AV incongruent emotional speech stimuli. Significant supra-additive responses were observed in right STS within the first 250 ms for emotionally incongruent and emotionally congruent AV speech stimuli, which further underscores the role of right STS in processing crossmodal emotive signals.     

The Influence of Art Expertise and Training on Emotion and Preference Ratings for Representational and Abstract Artworks

Across cultures and throughout recorded history, humans have produced visual art. This raises the question of why people report such an emotional response to artworks and find some works more beautiful or compelling than others. In the current study we investigated the interplay between art expertise, and emotional and preference judgments. Sixty participants (40 novices, 20 art experts) rated a set of 150 abstract artworks and portraits during two occasions: in a laboratory setting and in a museum. Before commencing their second session, half of the art novices received a brief training on stylistic and art historical aspects of abstract art and portraiture. Results showed that art experts rated the artworks higher than novices on aesthetic facets (beauty and wanting), but no group differences were observed on affective evaluations (valence and arousal). The training session made a small effect on ratings of preference compared to the non-trained group of novices. Overall, these findings are consistent with the idea that affective components of art appreciation are less driven by expertise and largely consistent across observers, while more cognitive aspects of aesthetic viewing depend on viewer characteristics such as art expertise.     

Selection of Reference Genes for Normalizing Gene Expression During Seed Priming and Germination Using qPCR in Zea mays and Spinacia oleracea

Quantitative real-time RT-PCR (qPCR) has been widely used to investigate gene expression during seed germination, a process involving seed transition from dry/physiologically inactive to hydrated/active state. This transition may result in altered expression of many housekeeping genes (HKGs), conventionally used as internal controls, thereby posing a challenge about selection of HKGs in such scenarios. The objectives of this study included identifying valid reference genes for seed priming and germination studies, both of which involve the transition of seed hydration status, and assessing whether or not findings derived from the “seed model” used in this study would also be applicable to other plant species. Eight commonly used HKGs were evaluated in maize seeds during hydropriming and germination. Using Bestkeeper, geNorm, and NormFinder, we provided a rank of stability for these HKGs. Actdf, UBQ, βtub, 18S, Act, and GAPDH were adjudged as valid internal controls by geNorm and NormFinder. Under the second objective, we conducted a case study with spinach seeds collected during osmopriming and germination. Our results indicate that the conclusions derived from maize were applicable to spinach as well, in that 18S exhibited greater expression stability than GAPDH in osmoprimed and germinated seeds; this held true even under stress conditions. While both of these genes were rejected by BestKeeper, we found that 18S exhibited stable expression when “dry” and “hydrated” seeds were analyzed as separate data sets. Although this approach precludes the comparison between “hydrated” and “dry” seeds, it still provides effective comparison among samples of same hydration status.