Happy to See Me,Aren’t You,Sally? Signal Detection Analysis of Emotion Detection in Briefly Presented Male and Female Faces

Using signal detection methods, possible effects of emotion type (happy, angry), gender of the stimulus face, and gender of the participant on the detection and response bias of emotion in briefly presented faces were investigated. Fifty-seven participants (28 men, 29 women) viewed 90 briefly presented faces (30 happy, 30 angry, and 30 neutral, each with 15 male and 15 female faces) answering yes if the face was perceived as emotional and no if it was not perceived as emotional. Sensitivity [d', z(hit rate) minus z(false alarm rate)] and response bias (β, likelihood ratio of "signal plus noise" vs. "noise") were measured for each face combination for each presentation time (6.25, 12.50, 18.75, 25.00, 31.25 ms). The d' values were higher for happy than for angry faces and higher for angry-male than for angry-female faces, and there were no effects of gender-of-participant. Results also suggest a greater tendency for participants to judge happy-female faces as emotional, as shown by lower β values for these faces as compared to the other emotion-gender combinations. This happy-female response bias suggests, at least, a partial explanation to happy-superiority effects in studies where performance is only measured as percent correct responses, and, in general, that women are expected to be happy.     

On the development and mechanics of delayed matching-to-sample performance

Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more secure foundation for assessing stability in future research. Six pigeons were exposed to a DMTS task with variable delays for 300 sessions (i.e., 18,000 total trials; 3,600 trials per retention interval). Percent-correct and log-d measures used to quantify the development of conditional stimulus control under the procedure generally and at each of five retention intervals (0, 2, 4, 8 and 16-s) individually revealed that high levels of accuracy developed relatively quickly under the shorter retention intervals, but increases in accuracy under the longer retention intervals sometimes were not observed until 100-150 sessions had passed, with some still increasing at Session 300. Analyses of errors suggested that retention intervals induced biases by shifting control from the sample stimulus to control by position, something that was predicted by observed response biases during initial training. These results suggest that although it may require a great deal of exposure to DMTS prior to obtaining asymptotic steady state, quantification of model parameters may help predict trends when extended exposure is not feasible.     

Musicians and tone-language speakers share enhanced brainstem encoding but not perceptual benefits for musical pitch

Behavioral and neurophysiological transfer effects from music experience to language processing are well-established but it is currently unclear whether or not linguistic expertise (e.g., speaking a tone language) benefits music-related processing and its perception. Here, we compare brainstem responses of English-speaking musicians/non-musicians and native speakers of Mandarin Chinese elicited by tuned and detuned musical chords, to determine if enhancements in subcortical processing translate to improvements in the perceptual discrimination of musical pitch. Relative to non-musicians, both musicians and Chinese had stronger brainstem representation of the defining pitches of musical sequences. In contrast, two behavioral pitch discrimination tasks revealed that neither Chinese nor non-musicians were able to discriminate subtle changes in musical pitch with the same accuracy as musicians. Pooled across all listeners, brainstem magnitudes predicted behavioral pitch discrimination performance but considering each group individually, only musicians showed connections between neural and behavioral measures. No brain-behavior correlations were found for tone language speakers or non-musicians. These findings point to a dissociation between subcortical neurophysiological processing and behavioral measures of pitch perception in Chinese listeners. We infer that sensory-level enhancement of musical pitch information yields cognitive-level perceptual benefits only when that information is behaviorally relevant to the listener.     

Impact of motivation on cognitive control in the context of vigilance lowering: an ERP study

We assessed the effects of time-on-task on cognitive control expressed by the CRN/Nc and the extent to which motivation modulates this relationship. We utilized two groups of participants, who were told that their performance would (evaluation condition) or would not (control condition) be evaluated online. Both groups performed a version of the Eriksen Flanker Task for 60 min. We observed classical vigilance lowering, manifested by a progressive performance decline with time-on-task, in the control, but not in the evaluation, condition. In the latter, performance remained stable throughout the task. ERP analysis indicated the same interaction in our main component of interest, the CRN/Nc, whose amplitude decreased from the first to the last period in the control condition but remained stable over time in the evaluation condition. To our knowledge, this study is the first to demonstrate the impact of motivation on monitoring processes as indexed by the correct response negativity, in the context of a prolonged task. Vigilance lowering caused by a repetitive and prolonged flanker task, results in compromised response control and compromised control of correct responses. Our results suggest that alterations in ACC functioning may underlie vigilance decline and can be viewed as evidence that the action monitoring functions of the ACC can be positively affected by motivation.     

The size coding of responses: The size of switches and the force feedback

We aimed to understand which factors have a functional role in the size coding of responses, either the size of the switches or the force required to trigger each switch. This question is of relevance because it allows a better understanding of processes underlying action coding. In each trial, participants saw a small or large object. Depending on its colour, the participants had to press one of two switches. In the “size” condition, the response device consisted of two switches of different visual size, but both required the same amount of force. In the “force-feedback” condition, the response device consisted in two switches of identical visual size, but one switch required more force than the other. We found a compatibility effect in the “size,” not in the “force-feedback” condition, supporting that the size-coding of responses would be due to the size of the switches.     

A rapid effect of stimulus quality on the durations of individual fixations during reading

We developed a variant of the single fixation replacement paradigm (Yang & McConkie, 2001, 2004) in order to examine the effect of stimulus quality on fixation duration during reading. Subjects' eye movements were monitored while they read passages of text for comprehension. During critical fixations, equal changes to the luminance of the background produced either an increase (Up-Contrast) or a decrease (Down-Contrast) of the contrast of the text. The durations of critical fixations were found to be lengthened in the Down-Contrast but not the Up-Contrast condition. Ex-Gaussian modelling of the distributions of fixation durations showed that the reduction in stimulus quality lengthened the majority of fixations, and a survival analysis estimated the onset of this effect to be approximately 141 ms following fixation onset. Because the stimulus quality of the text during critical fixations could not be predicted or parafoveally previewed prior to foveation, the present effect can be attributed to an immediate effect of stimulus quality on fixation duration.     

情绪Stroop效应：威胁驱动还是反应偏差？

为了考查情绪Stroop效应的产生机制是威胁驱动还是反应偏差,本研究进行了两个实验.实验一用一般负性情绪词语和中性词语作为实验材料,实验二用威胁性的情绪图片和中性图片作为实验材料.每个实验均要求一组被试做按键反应,另一组被试做摇杆反应.结果发现,当实验材料为词语时,未出现情绪Stroop效应;当实验材料为威胁性图片时,无论是趋向性反应方式还是回避性反应方式,都出现了情绪Stroop效应.本研究结果支持威胁驱动机制.     

基于作答时间数据的改变点分析在检测加速作答中的探索——已知和未知项目参数

相对于传统的离散作答数据, 作答时间作为连续数据, 可以提供更多信息。改变点分析(change point analysis)技术在心理和教育领域是一个比较新的技术。本文一方面对改变点分析在心理测量领域的应用进行了一个综合的总结和分析; 另一方面, 将基于作答数据的两种改变点分析统计量推广到作答时间数据, 将改变点分析技术应用到测验异常作答模式：加速作答speededness的检测上。采用两种检验方法：似然比检验和Wald检验, 分别在已知和未知项目参数的条件下, 实现异常作答模式的检测。结果表明, 所采用的方法对于加速作答行为的检测具有很高的检验力, 同时能够很好的控制I类错误率。实证数据分析进一步表明本文中所使用的方法具有应用价值。     

提取过程越久记忆保持越好吗？材料难度的调节作用

提取练习效应揭示了提取对记忆保持的关键意义;学习时间分配的有关研究表明提取练习效应的大小可能与材料难度有关。两个实验探讨了提取时间与材料难度对提取练习效应的影响：实验1采用2（提取时间：短,长）×2（材料难度：容易,困难）的混合设计,5分钟后测查记忆保持水平。实验2采用类似设计,将最终测试间隔延长至24小时。结果发现,⑴ 延长提取时间均提高了记忆成绩和记忆保持率。⑵ 即时测试条件下,提取时间较短时,不同难度材料的记忆成绩差异不显著;提取时间较长时,困难材料的记忆成绩高于容易材料;困难材料的记忆保持率在不同提取时间下均高于容易材料。⑶ 延迟测试条件下,无论提取时间长短,困难材料的记忆成绩及保持率均高于容易材料。研究表明,延长提取时间对提取练习效应的影响受材料难度的调节;情境背景和必要难度是解释该调节作用的可能理论框架。     

A hierarchy of cortical responses to sequence violations in three-month-old infants

The adult human brain quickly adapts to regular temporal sequences, and emits a sequence of novelty responses when these regularities are violated. These novelty responses have been interpreted as error signals that reflect the difference between the incoming signal and predictions generated at multiple cortical levels. Do infants already possess such a hierarchy of violation-detection mechanisms? Using high-density recordings of event-related potentials during an auditory local–global violation paradigm, we show that three-month-old infants process novelty in temporal sequences at two distinct levels. Violations of local expectancies, such as perceiving a deviant vowel “a” after repeated presentation of another vowel i-i-i, elicited an early auditory mismatch response. Conversely, violations of global expectancies, such as hearing the rare sequence a-a-a-a instead of the frequent sequence a-a-a-i, modulated this early mismatch response and led to a late frontal negative slow wave, whose cortical sources included the left inferior frontal region. These results suggest that the infant brain already possesses two dissociable systems for temporal sequence learning.