Intra-individual variability and psychological flexibility: Affect and health in a National US sample

Intra-individual variability (IIV) and psychological flexibility (PF) in affect both describe affective change over time (i.e., within-person variability). However, IIV and PF might differ from each other and predict different psychological and physical health outcomes. A large sample of adults (n = 793) completed two assessments of daily stress, daily affect, and health over a 10-year interval in The National Study of Daily Experiences (an 8-day daily diary portion of the Midlife Development in the United States study). IIV and PF in affect were modestly reliable within and between assessments. IIV, operationalized as total variability, predicted worse psychological and physical health concurrently and prospectively. PF, operationalized as changes in dimensionality, predicted better psychological and physical health concurrently and prospectively. Other operationalizations of PF were not consistently related to health. Within-person variability in affect could therefore be adaptive or maladaptive depending on how it was defined.     

Daily variations in attachment anxiety and avoidance: A density distributions approach

Attachment theory proposes that experiences of acceptance and rejection will modify feelings of attachment security, but such processes have rarely been investigated. In this study, daily variations in attachment anxiety and avoidance were investigated across 7 days in a sample of college undergraduates currently in romantic relationships. We observed significant within-person variation in attachment avoidance and anxiety. Participants reported lower anxiety and avoidance on days on which they felt more accepted by their romantic partners. Further, perceptions of acceptance predicted the following day’s attachment security through lower negative mood. Greater variability in attachment avoidance and anxiety was associated with greater physical aggression in relationships.     

Examining the within-person effect of affect on daily satisfaction

Assessments of global life satisfaction capture beliefs about overall well-being; state satisfaction assessments focus on short-term or “in-the-moment” appraisals of current life circumstances. Prior research has examined how trait measures of life satisfaction and affect are related at between-person and within-person levels of analysis. At the state level, however, a lack of clarity exists about the nature and magnitude of the association between satisfaction and affect. In a diary study involving assessments of both affect and satisfaction at the daily level (N = 350 with 6024 assessments), we found a consequential effect of affect on state satisfaction due to greater within-person variance over time.     

Impact of series length on statistical precision and sensitivity of autocorrelation assessment in human locomotion

Long-range autocorrelations (LRA) are a robust feature of rhythmic movements, which may provide important information about neural control and potentially constitute a powerful marker of dysfunction. A clear difficulty associated with the assessment of LRA is that it requires a large number of cycles to generate reliable results. Here we investigate how series length impacts the reliability of LRA assessment. A total of 94 time series extracted from walking or cycling tasks were re-assessed with series length varying from 64 to 512 data points. LRA were assessed using an approach combining the rescaled range analysis or the detrended fluctuation analysis (Hurst exponent, H), along with the shape of the power spectral density (α exponent). The statistical precision was defined as the ability to obtain estimates for H and α that are consistent with their theoretical relationship, irrespective of the series length. The sensitivity consisted of testing whether significant differences between experimental conditions found in the original studies when considering 512 data points persisted with shorter series. We also investigate the use of evenly-spaced diffusion plots as a methodological improvement of original version of methods for short series. Our results show that the reliable assessment of LRA requires 512 data points, or no shorter than 256 data points provided that more robust methods are considered such as the evenly-spaced algorithms. Such series can be reasonably obtained in clinical populations with moderate, or even more severe, gait impairments and open the perspective to extend the use of LRA assessment as a marker of gait stability applicable to a broad range of locomotor disorders.     

Do People Order Cues by Retrieval Fluency when Making Probabilistic Inferences?

In multiple‐cue probabilistic inferences, people infer alternatives' unknown values on decision criteria, using alternatives' attributes as cues. Some inferential strategies, like take‐the‐best, assume that people consider relevant cues sequentially in order of decreasing validity. This assumption has been deemed cognitively implausible by some, who suggest memory retrieval principles to guide cue order. We test whether memory‐based inferences are better described by a model considering cues in order of validity or in order of memory retrieval. In an experiment, we manipulated the frequency with which cues appeared in a learning phase, increasing retrieval fluency of cue values related to the more frequently appearing cue. In a subsequent decision phase, participants made a series of two‐alternative decisions based on the learned cue values. We compared two sequential sampling models, which differed in whether cues are sampled in order of subjective cue validity or in order of retrieval fluency. To model retrieval order of cues in the fluency sampling model, we used the declarative memory theory embedded in the ACT‐R cognitive architecture. Most participants' decisions were best described by the model sampling cues in order of memory retrieval. Only a minority of participants were classified as sampling cues by validity. Our result suggests that retrieval fluency is the primary driver of cue order in inferences from memory, irrespective of the cues' validities. Copyright © 2017 John Wiley & Sons, Ltd.     

Studying the variability of handwriting patterns using the Kinematic Theory

The variability observed in handwriting patterns is analyzed from the perspective of integrating the resulting motor control knowledge in the design of more powerful handwriting recognizers in personal digital assistants (PDAs) and smartphones. Using the highest representational level of the Kinematic Theory of Rapid Human Movement, the Sigma-Lognormal model, this article reports basic theoretical and practical results that could be taken into account in the design of such systems. The main movement variability introduced by the neuromuscular system (NMS) and induced through the scheduling of motor tasks by the central nervous system (CNS) is divided into global and local fluctuations. From a fiducial action plan decoded by this model, a wide range of handwriting distortions are artificially generated by acting on the Sigma-Lognormal parameters. The resulting patterns are studied to understand scale changes and rotational deformations, the two basic features that a recognizer has to take into account. An experiment based on the writing of the same word by six writers is also reported. The results, obtained by an ANOVA analysis, corroborate the predictions and support the relevance of the Kinematic Theory for the analysis and synthesis of handwriting disruptions. These findings consolidate the results of previous studies on single strokes using the Sigma-Lognormal model. Overall, this report provides new insights into our understanding of motor control, as well as into practical cues for the development of huge databases of letters and words to train and test on-line handwriting classifiers and recognizers.     

Statistical inference and sensitivity to sampling in 11-month-old infants

Research on initial conceptual knowledge and research on early statistical learning mechanisms have been, for the most part, two separate enterprises. We report a study with 11-month-old infants investigating whether they are sensitive to sampling conditions and whether they can integrate intentional information in a statistical inference task. Previous studies found that infants were able to make inferences from samples to populations, and vice versa [Xu, F., & Garcia, V. (2008). Intuitive statistics by 8-month-old infants. Proceedings of the National Academy of Sciences of the United States of America, 105, 5012-5015]. We found that when employing this statistical inference mechanism, infants are sensitive to whether a sample was randomly drawn from a population or not, and they take into account intentional information (e.g., explicitly expressed preference, visual access) when computing the relationship between samples and populations. Our results suggest that domain-specific knowledge is integrated with statistical inference mechanisms early in development.     

任务难度、决策培训诸因素对群体决策的影响

通过3人群体的人员选拔模拟实验。考察了任务难度、群体结构和决策培训三个变量对群体决策信息取样的影响。结果显示：(1)部分证明了Stasser的信息取样模型,分享信息具有讨论的优势,同时偏好是影响群体决策的中介因素,但是,该模型只适合于任务难度较大的情况;(2)设立具有信息管理作用的领导者这种群体结构在信息取样中没有表现出主效应,它只是通过与决策培训和任务难度一起对信息取样产生影响;(3)策略计划和信息警戒性的决策培训对信息取样有影响,一定程度上提高了非分享信息的讨论比例,然而这种影响仅发生在任务难度小或适中的情况下。决策培训对信息取样的影响发生在讨论的开始部分,并影响了讨论前的个体偏好;(4)群体结构和决策培训具有交互作用,从而影响了群体讨论的信息取样,群体结构和决策培训都受到任务难度的影响。     

Implications of accuracy, sensitivity, and variability of body size estimations to disordered eating

The current study was conducted to investigate the relationships between body size estimations and disordered eating symptomatology. The method of constant stimuli was used to derive three measures of self-perceived body size in 93 women: (1) accuracy of body size estimations (body image distortion); (2) sensitivity in discriminating body size within blocks of trials (body image sensitivity); and (3) variability in making body size estimations between blocks of trials (body image variability). Participants also completed measures of disordered eating. Although body image distortion correlated with dietary restraint and eating concern, body image variability accounted for additional variance in these variables, as well as variance in binge eating. The relationships involving body image variability were found to be mediated by body dissatisfaction and internalization of the thin ideal. Together, these results are consistent with the proposition that body image variability is a significant factor in disordered eating.     

Mood trajectories following daily life events

Little is known about the magnitude and duration of mood responses to daily negative events as a function of gender, history of mood disorder, and current substance use. Using computerized ambulatory monitoring techniques, perceived negativity of minor daily events and state affect were prospectively examined every 3 h on average for a 7-day period. Event negativity was associated with depressed mood for 6–9 h following event occurrence, and was associated with happy mood for 3–6 h. Gender and substance use moderated the relationship between event negativity and mood states concurrently, and remained influential for approximately 3 h following the event. History of mood disorder did not moderate any within- or across-day relationships between event negativity and mood. No evidence was found for mood uplifts following daily events in either within- or across-day analyses. The findings are discussed relative to assessment timing in investigations of vulnerability-stress theories.