Failure to replicate the 'work ethic" effect in pigeons

We report six unsuccessful attempts to replicate the "work ethic" phenomenon reported by Clement, Feltus, Kaiser, and Zentall (2000). In Experiments 1-5, pigeons learned two simultaneous discriminations in which the S+ and S- stimuli were obtained by pecking an initial stimulus once or multiple (20 or 40) times. Subsequent preference tests between the S+ stimuli and between the S- stimuli mostly revealed indifference, on average, between the S+ from the multiple-peck (high-effort) trials and the S+ from the one-peck (low-effort) trials, and likewise between the two respective Sstimuli. Using a slightly different procedure that permitted assessment of the relative aversiveness of low versus high effort, Experiment 6 again revealed a pattern of indifference despite showing that pigeons took considerably longer to begin pecking on high- than on low-effort trials. Our findings call into question the reliability of the original findings and the sufficiency of the hypothesized within-trial contrast mechanism to produce them.     

Valence specific laterality effects in prosody: expectancy account and the effects of morphed prosody and stimulus lead

The majority of studies have demonstrated a right hemisphere (RH) advantage for the perception of emotions. Other studies have found that the involvement of each hemisphere is valence specific, with the RH better at perceiving negative emotions and the LH better at perceiving positive emotions [Reuter-Lorenz, P., & Davidson, R.J. (1981) Differential contributions of the 2 cerebral hemispheres to the perception of happy and sad faces. Neuropsychologia, 19, 609-613]. To account for valence laterality effects in emotion perception we propose an 'expectancy' hypothesis which suggests that valence effects are obtained when the top-down expectancy to perceive an emotion outweighs the strength of bottom-up perceptual information enabling the discrimination of an emotion. A dichotic listening task was used to examine alternative explanations of valence effects in emotion perception. Emotional sentences (spoken in a happy or sad tone of voice), and morphed-happy and morphed-sad sentences (which blended a neutral version of the sentence with the pitch of the emotion sentence) were paired with neutral versions of each sentence and presented dichotically. A control condition was also used, consisting of two identical neutral sentences presented dichotically, with one channel arriving before the other by 7 ms. In support of the RH hypothesis there was a left ear advantage for the perception of sad and happy emotional sentences. However, morphed sentences showed no ear advantage, suggesting that the RH is specialised for the perception of genuine emotions and that a laterality effect may be a useful tool for the detection of fake emotion. Finally, for the control condition we obtained an interaction between the expected emotion and the effect of ear lead. Participants tended to select the ear that received the sentence first, when they expected a 'sad' sentence, but not when they expected a 'happy' sentence. The results are discussed in relation to the different theoretical explanations of valence laterality effects in emotion perception.     

Decision-making deficit of a patient with axonal damage after traumatic brain injury

Patients with traumatic brain injury (TBI) were reported to have difficulty making advantageous decisions, but the underlying deficits of the network of brain areas involved in this process were not directly examined. We report a patient with TBI who demonstrated problematic behavior in situations of risk and complexity after cerebral injury from a traffic accident. The Iowa gambling task (IGT) was used to reveal his deficits in the decision-making process. To examine underlying deficits of the network of brain areas, we examined T1-weighted structural MRI, diffusion tensor imaging (DTI) and Tc-ECD SPECT in this patient. The patient showed abnormality in IGT. DTI-MRI results showed a significant decrease in fractional anisotropy (FA) in the fasciculus between the brain stem and cortical regions via the thalamus. He showed significant decrease in gray matter volumes in the bilateral insular cortex, hypothalamus, and posterior cingulate cortex, possibly reflecting Wallerian degeneration secondary to the fasciculus abnormalities. SPECT showed significant blood flow decrease in the broad cortical areas including the ventromedial prefrontal cortex (VM). Our study showed that the patient had dysfunctional decision-making process. Microstructural abnormality in the fasciculus, likely from the traffic accident, caused reduced afferent feedback to the brain, resulting in less efficient decision-making. Our findings support the somatic-marker hypothesis (SMH), where somatic feedback to the brain influences the decision-making process.     

Retrieval Dynamics and Retention in Cross‐Situational Statistical Word Learning

Previous research on cross‐situational word learning has demonstrated that learners are able to reduce ambiguity in mapping words to referents by tracking co‐occurrence probabilities across learning events. In the current experiments, we examined whether learners are able to retain mappings over time. The results revealed that learners are able to retain mappings for up to 1 week later. However, there were interactions between the amount of retention and the different learning conditions. Interestingly, the strongest retention was associated with a learning condition that engendered retrieval dynamics that initially challenged the learner but eventually led to more successful retrieval toward the end of learning. The ease/difficulty of retrieval is a critical process underlying cross‐situational word learning and is a powerful example of how learning dynamics affect long‐term learning outcomes.     

Female copulatory orgasm and male partner’s attractiveness to his partner and other women

Women’s copulatory orgasm may function to retain sperm from men with “good genes”, one indicator of which is attractiveness, and one benefit of which is pathogen resistance. Women who perceive their partner to be more (vs. less) attractive are more likely to report orgasm at last copulation. Another benefit of male attractiveness to women is that he may sire offspring that will gain the heritable share of this advantage (i.e., “sexy sons”). Research has not addressed the “Sexy Sons” Hypothesis (e.g., as indicated by women’s perception of other women’s assessments of their partner’s attractiveness) in regards to female copulatory orgasm. We secured self-reports from 439 women in a committed, heterosexual relationship and investigated the relationships between women’s orgasm at last copulation and (1) women’s assessments of their partner’s attractiveness and (2) women’s perceptions of other women’s assessments of their partner’s attractiveness. The results indicate that women mated to more (vs. less) attractive men are more likely to report orgasm at last copulation, and this relationship is mediated by women’s perceptions of other women’s assessments of their partner’s attractiveness. We discuss the mediated relationship, note limitations of the research, and suggest future research directions.     

Properties of hypothesis testing techniques and (Bayesian) model selection for exploration‐based and theory‐based (order‐restricted) hypotheses

In this paper, the performance of six types of techniques for comparisons of means is examined. These six emerge from the distinction between the method employed (hypothesis testing, model selection using information criteria, or Bayesian model selection) and the set of hypotheses that is investigated (a classical, exploration‐based set of hypotheses containing equality constraints on the means, or a theory‐based limited set of hypotheses with equality and/or order restrictions). A simulation study is conducted to examine the performance of these techniques. We demonstrate that, if one has specific, a priori specified hypotheses, confirmation (i.e., investigating theory‐based hypotheses) has advantages over exploration (i.e., examining all possible equality‐constrained hypotheses). Furthermore, examining reasonable order‐restricted hypotheses has more power to detect the true effect/non‐null hypothesis than evaluating only equality restrictions. Additionally, when investigating more than one theory‐based hypothesis, model selection is preferred over hypothesis testing. Because of the first two results, we further examine the techniques that are able to evaluate order restrictions in a confirmatory fashion by examining their performance when the homogeneity of variance assumption is violated. Results show that the techniques are robust to heterogeneity when the sample sizes are equal. When the sample sizes are unequal, the performance is affected by heterogeneity. The size and direction of the deviations from the baseline, where there is no heterogeneity, depend on the effect size (of the means) and on the trend in the group variances with respect to the ordering of the group sizes. Importantly, the deviations are less pronounced when the group variances and sizes exhibit the same trend (e.g., are both increasing with group number).     

A matter of font type: The effect of serifs on the evaluation of scientific abstracts

Text‐based communication is one of the substantial ways of spreading scientific information. While the content and contextual aspects of written words have been widely researched, the impact of font characteristics on text perception is an almost blank page. The following study deals with the influence of serifs on the evaluation of online‐presented scientific abstracts. Yet there is only evidence for faster reading times when texts are presented in sans‐serif fonts, although the opposite is stated in parts of the literature. The present work examines if the presence or absence of serifs also have an impact on the appraisal of scientific texts when all other important font characteristics do not change. For this purpose, 188 university students participated in an online experiment and rated different aspects of scientific abstracts as well as of the research outlined in the abstracts. The results show that missing serifs led to increased reading speed. However, and in contrast to the perceptual fluency hypothesis, the presence of serifs had a positive effect on all evaluation dimensions. The results of a second study with 187 participants also indicated that reading fluency counteracted the liking of texts. Implications for future studies and media production are discussed.     

中文惯用语的加工：结构和熟悉性的作用

为探讨结构和熟悉性在惯用语加工中的作用,本研究操纵惯用语的结构（偏正、动宾）和熟悉性（高、低）,采用Eyelink 1000 plus记录104名大学生阅读包含惯用语的句子时的眼睛注视过程。结果发现：高熟悉惯用语的第一遍注视时间和总注视时间均短于低熟悉惯用语;只有加工低熟悉惯用语时,偏正结构惯用语的总注视时间短于动宾结构惯用语。结果说明,结构只影响低熟悉惯用语的晚期加工,偏正结构比动宾结构惯用语语义整合更容易;熟悉性影响惯用语整个加工过程,高熟悉比低熟悉惯用语加工更快。实验结果支持惯用语的混合模型。     

风险取向类型与爱荷华赌博任务成绩的影响

神经科学领域的研究者们设计了测量情感决策的经典爱荷华赌博任务并提出了体细胞标记假说来解释其研究结果,但迄今为止这一假说还没有得到一致认可。许多研究提出了可能影响爱荷华赌博任务成绩的其他因素。本研究试图在前人研究的基础上采用实验法探讨风险取向类型这一人格因素是否影响正常个体的爱荷华赌博任务成绩。实验结果显示,不同风险取向类型的个体在爱荷华赌博任务中的成绩和表现截然不同。典型风险趋向型个体在爱荷华赌博任务中的表现类似于某些神经系统患者,倾向于更多地选择不利纸牌,其任务成绩显著差于典型风险回避型个体。这一研究结果表明：风险取向类型是影响正常个体爱荷华赌博任务成绩的重要因素之一。     

母亲消极教养、同伴侵害与FKBP5基因对青少年抑郁的影响

累积压力假说与匹配-不匹配假说均可解释远端和近端逆境对个体抑郁的影响,但鲜有研究考察遗传基因在其中的调节作用。采用问卷法和DNA分型技术,对970名青少年进行间隔3年的追踪调查。分别以母亲消极教养、同伴侵害为远端和近端压力指标, FKBP5基因多位点累加得分为遗传指标,考察三者对青少年抑郁的交互作用及性别差异。结果发现,在男青少年中, E×E×G显著。当累加得分较高、同伴侵害水平较高时,母亲消极教养显著负向预测抑郁,符合匹配-不匹配假说;累加得分较低时, E×E不显著,但倾向于以累积压力假说的方式发挥作用。女青少年中, E×E×G不显著。研究结果提示,在男青少年中,累积压力假说与匹配-不匹配假说均可阐明抑郁的发生机制,分别适用于携带不同FKBP5基因多位点累加得分的个体。