The modulation of stimulus structure on visual field asymmetry effects: The case of Chinese character recognition

Recent research suggests that visual field (VF) asymmetry effects in visual recognition may be influenced by information distribution within the stimuli for the recognition task in addition to hemispheric processing differences: Stimuli with more information on the left have a right VF (RVF) advantage because the left part is closer to the centre, where the highest visual acuity is obtained. It remains unclear whether visual complexity distribution of the stimuli also has similar modulation effects. Here we used Chinese characters with contrasting structures—left-heavy, symmetric, and right-heavy, in terms of either visual complexity of components or information distribution defined by location of the phonetic component—and examined participants' naming performance. We found that left-heavy characters had the largest RVF advantage, followed by symmetric and right-heavy characters; this effect was only observed in characters that contrasted in information distribution, in which information for pronunciation was skewed to the phonetic component, but not in those that contrasted only in visual complexity distribution and had no phonetic component. This result provides strong evidence for the influence of information distribution within the stimuli on VF asymmetry effects; in contrast, visual complexity distribution within the stimuli does not have similar modulation effects.     

Brain asymmetry and autonomic conditioning: Sensitization control

In the present experiment we report effects of cerebral asymmetry, or laterality, during classical conditioning to facial emotional stimuli. Twenty-five female subjects were presented with slides of a happy face in one visual half-field (VHF), and simultaneously a slide of an angry face in the other VHF, followed by shock as the unconditioned stimulus (UCS). To control for effects of sensitization, a new stimulus, never associated with the UCS, was introduced in the extinction phase. Dependent measures were phasic heart rate responses (HR) and skin conductance responses (SCR). The HR results showed a significant right hemisphere effect for the CS-UCS association, that was not attributable to UCS sensitization. No significant effects were found for the SCRs. The basic HR finding was a right hemisphere superiority for learning of a conditioned association.     

道德概念垂直空间隐喻理解中的映射:双向性及不平衡性

通过4个实验考察道德概念垂直空间隐喻理解中的映射机制和特征。实验1采用空间Stroop范式,发现被试判断完道德词后,对判断随后呈现在屏幕上方或下方字母的反应时的差异不显著,没有发现词汇类型对空间位置的影响。实验2采用有意识迫选法,要求被试出声读出屏幕中央的道德词后,对屏幕上方或下方的希腊语非词进行二择一迫选,发现被试读出道德词后倾向于选择屏幕上方的非词,读出不道德词后倾向于选择屏幕下方的非词。实验3仍采用Stroop范式,发现被试做出空间"上"的判断后,对随后道德词的词义判断反应时显著快于不道德词,做出空间"下"的判断后,对不道德词的反应时显著快于道德词。实验4探讨空间位置是否会对判断人物的道德性产生影响,结果发现被试倾向于认为屏幕上方的人物是道德的,而屏幕下方的人物是不道德的。4个实验的结果表明,在道德概念垂直空间隐喻的理解中,映射的方式是灵活的、双向的,既可以由始源域向目标域映射,也可以由目标域向始源域映射,但两个方向上的映射力量是不平衡的。     

Is sexual-aggressive vocal communication related to asymmetric mechanisms in the brain?

In Mongolian gerbil males, a reliable asymmetric relationship has been discovered between a stereotyped ultrasonic vocalizattion and the volume of a discrete nucleus within the preoptic-anterior hypothalamic area, the sexually dimorphic area, pars compacta (SDApc). The steroid-sensitive ultrasonic, emitted at high levels during courtship interactions, is associated with the absence of aggressive encounters and appears to be necessary for the formation and maintenance of pair-bonds with females. Interactions between unfamilliar, non-pair-bonded adult male and estrous female gerbils result in male aggression, reduction of male ultrasonic calling, and disruption of normal female dartmale follow sociosexual sequences. Castration further reduces ultrasonic calling, inhibits normal sociosexual sequences, and increses aggression in interaction between unfamiliar compared to pair-bonded individuals. Bothg brain structure and lateralization of vocal function in males depend on the action of sex steroids during sexual differentiation and in adulthood. Thus, the gerbil provides a new model to study steroid-dependent lateralization of brain mechanisms of vocal behavior mediating aggressive-sexual relationships. © 1994 Wiley-Liss, Inc.     

Close to me: The importance of closeness versus superficiality in explaining the positive-negative contact asymmetry

The evidence for differential effects of positive and negative intergroup contact on prejudice is mixed. We propose that the closeness of the relationships respondents have with contact partners can explain inconsistencies in previous findings. In three studies (total N = 953), we tested the associations between positive intimate, negative intimate, positive superficial, and negative superficial contact and attitudes toward different outgroups (immigrants and gay people). We hypothesized that: (H1) the effect of positive contact would be maximized in intimate interactions; (H2) the effect of negative contact would be maximized in superficial interactions; (H3) positive intimate and negative superficial contact would have similar power in predicting attitudes. Results always supported H1, and supported H2 and H3 only with immigrants. Findings held also when controlling for category salience and agreeableness, but not for social dominance orientation, which instead strengthened the effect of negative superficial contact. Overall, findings clarify the positive–negative contact asymmetry.     

Is apparent instability a guiding feature in visual search?

ABSTRACT

Humans are quick to notice if an object is unstable. Does that assessment require attention or can instability serve as a preattentive feature that can guide the deployment of attention? This paper describes a series of visual search experiments, designed to address this question. Experiment 1 shows that less stable images among more stable images are found more efficiently than more stable among less stable; a search asymmetry that supports guidance by instability. Experiment 2 shows efficient search but no search asymmetry when the orientation of the objects is removed as a confound. Experiment 3 independently varies the orientation cues and perceived stability and finds a clear main effect of apparent stability. Experiment 4 shows converging evidence for a role of stability using different stimuli that lack an orientation cue. However, here both search for stable and unstable targets is inefficient. Experiment 5 is a control for Experiment 4, showing that the stability effect in Experiment 4 is not simple side-effects of the geometry of the stimuli. On balance, the data support a role for instability in the guidance of attention in visual search. (184 words)     

Does frontal brain activity mediate the effect of depression prevention in adolescents? A pilot study

We investigated whether (a) depression prevention was associated with depressive symptoms and medial-frontal alpha asymmetry in adolescents; (b) alpha asymmetry mediated the association between participation in a prevention program and depressive symptoms; and (c) gender affects these associations. In our randomised control group study, we compared a universal prevention program (n = 40 adolescents, 14 females) with a non-intervention control condition (n = 39 adolescents, 20 females) in German secondary school students (mean age: 13.53 years, SD = 0.53). We collected data at baseline, post-intervention, 6-month, and 12-month follow-up using the Self-Rating Questionnaire for Depressive Disorders (SBB-DES) and resting medial-frontal alpha activity on F3 and F4. We found that girls benefitted from participating in the prevention program in regards to their depressive symptoms at 12-month follow-up but not alpha asymmetry. In boys, participation in the prevention program was associated with their alpha asymmetry at 6-month follow-up but not their depressive symptoms. Alpha asymmetry did not mediate the effects of the prevention program on depressive symptoms in either gender. Although participation in the prevention program was associated with both depressive symptoms and alpha asymmetry, those associations seem independent from each other. Possible explanations for this result pattern are discussed.     

医管、医患双重博弈研究

在中国,老百姓"看病难,看病贵"问题已饱受各方诟病多时,政府不断出台的政策却收效甚微。通过分析医疗机构、管制者和患者所面临的风险与收益、行为与选择、医疗机构与管制者之间的重复博弈,医疗机构与患者之间的一次性博弈,提出医疗机构与管制者、医疗机构与患者的双重博弈假说。指出了"药价虚高"的根源以及解决的可能途径。     

关于上下视野不对称性的研究

该研究就国内外对上下视野不对称性的研究成果做了详细的阐述,主要包括上下视野的定义、上下视野不对称性的行为和神经机制方面的研究成果及当前所面临的问题,并在文章的最后提出自己的观点。     

European starlings are capable of discriminating subtle size asymmetries in paired stimuli

Small deviations from bilateral symmetry (fluctuating asymmetries) are cues to fitness differences in some animals. Therefore, researchers have considered whether animals use these small asymmetries as visual cues to determine appropriate behavioral responses (e.g., mate preferences). However, there have been few systematic studies of animals' abilities to visually discriminate such minor asymmetries. If the asymmetries cannot be discriminated, fluctuating asymmetry can not be a visual cue. Here, we report an investigation of European starlings' (Sturnus vulgaris) abilities to discriminate small size asymmetries. We trained starlings, through operant conditioning in a free-flight aviary, to discriminate achromatic, symmetric paired stimuli from size-matched asymmetric stimuli. By starting the learning process with a large asymmetry and progressing through sequential trials of decreasing asymmetry, we elucidated a behavioral limit to asymmetry discrimination. We found that starlings are capable of discriminating a 10% size asymmetry. There was weaker evidence for discrimination of 5% asymmetry but no evidence for signal discrimination at 2.5% size asymmetry. This level of asymmetry discrimination suggests that many size asymmetry cues in nature can be discriminated by birds. At each level of asymmetry discrimination, we also tested whether starlings could generalize their learned symmetry preference to unreinforced novel images. Consistent with previous findings, we found that starlings could generalize their symmetry preferences.