When is the Wilcoxon–Mann–Whitney procedure a test of location? Implications for effect-size measures

The Wilcoxon–Mann–Whitney procedure is invariant under monotone transformations but its use as a test of location or shift is said not to be so. It tests location only under the shift model, the assumption of parallel cumulative distribution functions (cdfs). We show that infinitely many monotone transformations of the measured variable produce parallel cdfs, so long as the original cdfs intersect nowhere or everywhere. Thus there are infinitely many effect sizes measured as shifts of medians, invalidating the notion that there is one true shift parameter and thereby rendering any single estimate dubious. Measuring effect size using the probability of superiority alleviates this difficulty.     

Evidence for altered configural body processing in women at risk of disorders characterized by body image disturbance

Two studies were conducted to assess appearance-related visual processing mechanisms in populations at risk of disorders characterized by body image disturbance. Using inverted stimuli, Experiment 1 assessed visual processing mechanisms associated with body, face, and house viewing in adolescents. Experiment 2 applied the same protocol to assess appearance-related configural processing in high- and low-risk adolescent women, and women recovering from disorders characterized by body image disturbance. Experiment 1 found evidence for typical configural face and body processing, although adolescent women reported higher levels of body image concern (BIC) and self-objectified to a greater extent than adolescent men. In Experiment 2, typical body inversion effects were seen in the low-risk group, whilst there was some evidence to suggest a disruption to the configural processing of body stimuli in high-risk adolescents and in women recovering from body image disorders. Women in recovery were also quicker to respond to all stimuli, whilst high-risk adolescents took longer to respond to bodies than to other stimuli. Configural face processing was intact in all groups, and effects did not directly relate to BIC or self-objectification. These findings have implications for future research looking to inform early interventions and treatment, suggesting that there could be a tendency to visually process individual body parts at the expense of the whole-body form in women at risk of developing body image disorders, as well as those in recovery.     

Misunderstandings and omissions in textbook accounts of effect sizes

There have been frequent attempts in psychology to reduce the reliance on null hypothesis significance testing (NHST) as the criterion for establishing the importance of results. Many authorities now recommend the reporting of effect sizes (ESs) as a supplement or alternative to NHST. However, there is extensive specialist literature highlighting problems associated with the use and interpretation of ESs. A review of the coverage of ESs in over 100 textbooks on statistical analysis in behavioural science revealed widespread neglect of ESs and the relevant critical issues that have widespread coverage in the more specialist literature. For example, many textbooks claim that ESs should be interpreted as a simple measure of the practical real-world importance of a result despite the fact that ESs are profoundly influenced by features of design and analysis strategy. We seek to highlight areas of misunderstanding about ESs found in the pedagogical literature in the light of the more specialist literature and make recommendations to researchers for the appropriate use and interpretation of ESs. This is critical as statistics textbooks have a crucial role in the education of researchers.     

A comparison of picture and GIF-based preference assessments for social interaction

Researchers have recently begun to evaluate video-based preference assessments; however, only two studies have evaluated the efficacy of this preference assessment modality in assessing preference for social interactions. Four individuals diagnosed with autism spectrum disorder who could not match pictures or graphic-interchange-format images (GIFs) of social interactions to in vivo interaction participated. We compared picture and GIF-based paired-stimulus preference assessments for social interaction and evaluated the preference assessment hierarchies by conducting a concurrent-operant reinforcer assessment including all social interactions. The GIF-based preference assessment produced similar hierarchies to the reinforcer assessment for all participants, whereas the picture-based preference assessments produced similar hierarchies to the reinforcer assessment for 2 of 4 subjects. Additionally, we conducted a modality preference assessment in which we evaluated participants' preference for viewing GIFs or pictures of social interactions, and found that 3 out of 4 subjects displayed a preference for GIFs.     

A comparison of methods for assessing preference for social interactions

Researchers have evaluated a variety of methods for assessing preference for social interactions, and generally have found that such assessments accurately identify differentially reinforcing, preferred interactions. However, few researchers have compared methods for assessing preference for social interactions, and none have done so with participants across different skill levels. The current study compared the stability and validity of hierarchies produced by social interaction preference assessments (SIPA) and picture-based multiple stimulus without replacement preference assessments (MSWO) with 8 individuals diagnosed with autism spectrum disorder (ASD). The MSWO most often produced valid hierarchies for participants who could match, identify, and tact pictures of social interactions and that the SIPA most often produced valid hierarchies for participants who could not identify or tact pictures of social interactions. A vocal paired-stimulus preference assessment (PSPA) was also conducted with a subset of participants who communicated vocally, and it produced valid hierarchies. Considerations and recommendations for selecting a method of assessing preference for social interactions are discussed.     

Creators and Presses: The Person–Situation Interaction in Negative Creativity

Given the recent emphasis on exploring valence in creative behavior, this study examines negative creativity via a person–situation interactionist perspective. By manipulating goal valence (uses or misuses) and object valence (positive or negative), four conditions of an adapted Divergent Thinking task were used to predict positive and negative creativity. Participants (N = 178, 103 females, M_age = 23.82, SD = 4.03, range: 18–38) responded to a single condition along with the Big Five and Dark Triad personality scales in a between-groups design. Hierarchical multiple regressions revealed that goal and object valence significantly explained variance in valences of creative responses, beyond individual differences of personality. Furthermore, the congruence between goal and object valence predicted valenced creativity; that is, the positive objects and goals condition yielded more positive-original ideas, and the negative objects and goals condition yielded more negative-original ones. Object valence alone (material presses) did not contribute significantly to explaining valenced creativity. Negative-original responses were inversely related to conscientiousness, and directly to intellect/imagination and secondary psychopathy. Thus, negative creativity was attributed relatively more to person as compared to situation variables. Results are discussed from a valence-based and interactionist perspective.     

Assessing the impact of a family nurse-led intervention on young mothers’ references to internal states

A mother's propensity to refer to internal states during mother–child interactions is important for her child's developing social understanding. However, adolescent mothers are less likely to reference internal states when interacting with their children. We investigated whether young mothers’ references to internal states are promoted by the Family Nurse Partnership (FNP) intervention, an intensive home-visiting programme designed to support adolescent mothers in England. We also investigated family, maternal, and child factors associated with young mothers’ references to inner states during interactions with their children. Adolescent mothers (n = 483, aged ≤ 19 years when recruited in pregnancy) and their children participated in an observational substudy of a randomized controlled trial investigating the impact of FNP compared to usual care. Mother–child dyads were video-recorded during free play, and mothers’ speech was coded for use of internal state language (references to cognitions, desires, emotions, intentions, preferences, physiology, and perception). We found no differences in mothers’ use of internal state language between the FNP and usual care groups. A sample-wide investigation identified that other features of mothers’ language and relationship status with the child's father were associated with internal state language use. Findings are discussed with reference to targeted interventions and implications for future research.     

视觉工作记忆回溯线索效应的产生机制：认知阶段分离

以往研究关于视觉工作记忆回溯线索效应的产生机制主要存在5种假设, 目前依然存在争议。本研究通过改进前人研究实验范式, 采用包含内源性回溯线索的颜色回忆报告范式, 进一步对这5种假设进行检验。在实验1中, 我们调控了线索与探测阵列之间的时间间隔, 发现不同时间间隔不影响无线索条件的行为表现, 而在正常线索条件中被试的记忆精度以及能记住的项目数量均优于无线索条件; 在实验2中, 我们对回溯线索伴随的干扰刺激类型进行控制, 结果显示, 在不同条件下记忆精度不存在差别, 但当回溯线索伴随干扰刺激呈现时, 被试能记住的项目数量会被降低, 降低程度受干扰刺激的类型调制; 在实验3中, 我们对伴随回溯线索的干扰刺激的呈现时间进行控制, 发现虽然回溯线索效应仍然存在, 但干扰刺激的呈现时间不会影响效应程度。研究结果表明, 回溯线索的出现使得被试能够在决策加工前完成内部注意资源的再分配, 从而避免了同时进行这两种认知加工与记忆表征维持本身竞争认知资源。本研究为认知阶段分离假设提供了支持证据, 对解决回溯线索效应产生机制的争议以及理解内部注意与视觉工作记忆的关系有重要意义。