CAN A DECAY PROCESS EXPLAIN THE TIMING OF CONDITIONED RESPONSES?

To explain time-scale invariant distributions of response latencies, it appears to be necessary to postulate scalar noise in the remembered intervals, against which the subjective measure of the currently elapsing interval is compared. At least in some cases, the observed variability cannot be due to variability in the subjective intervals written to memory; it must come from noise (variability) in the reading of a memory. The Staddon and Higa proposal offers no explanation for the observed variability, and it is unclear what noise assumption would yield the observed variability, given their assumption that intervals are timed by a nonlinear decay process. The decay process cannot plausibly be represented by the logarithmic function, because it begins and ends at infinity. The assumption of any form of nonlinear timing is inconsistent with the most important result of the time-left experiment, which is that the changeover time increases linearly with the comparison-standard difference.     

Group Attachment and the Reduction of Value-Driven Ambivalence

This article analyzes the effects of value-driven ambivalence and group attachment on response variability in public attitudes toward campaign finance reform. The analysis demonstrates that group attachment, when activated by affective cues, moderates the effects of ambivalence on response variability. By tipping the balance of considerations in one direction or the other, group attachments make it easier for ambivalent respondents to make tradeoffs between competing values during policy choices and, as a result, dampen response variability. Methodologically, the results offer an important cautionary note about the use of linear ambivalence scales by calling into question the assumption that indifference is an intermediate state between preference and ambivalence.     

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.     

The development of functional response units: the role of demarcating stimuli.

An experiment with rats examined the roles of demarcating stimuli and differential reinforcement probability on the development of functional response units. It examined the development of units in a probabilistic, free-operant situation in which the presence of demarcating stimuli was manipulated. In all conditions, behavior became organized into two-response sequences framed by changes in local reinforcement probability. A tone demarcating the beginning and end of contingent response sequences facilitated the development of functional response units, as in chunking, but the same units developed slowly in the absence of the tone. Complex functional response units developed even though reinforcement contigencies remained constant. These findings demonstrate that models of operant learning must include a mechanism for changing the response unit as a function of reinforcement history. Markov models may seem to be a natural technique for modeling response sequences because of their ability to predict individual responses as a function of reinforcement history; however, no class of Markov chain can incorporate changing response units in their predictions.     

统计概要表征的内容与机制

人类能够快速提取集合刺激中的统计信息, 并形成以集中趋势和变异性为主要内容的统计概要表征。根据注意资源的使用, 统计概要表征的加工方式可分为分布式注意下的整体加工和聚焦注意下的个体加工。两种加工在工作记忆中相互影响, 共同构建了对集合刺激的表征。统计概要表征适用于多种刺激类型, 发生在低水平和高水平加工中, 因而可能是一种普遍的知觉加工方式。未来研究可关注统计概要表征的神经基础及其对决策的影响。     

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.     

Analysis of Pelvis-Thorax Coordination Patterns of Professional and Amateur Golfers during Golf Swing

The aim of this research was to quantify the coordination pattern between thorax and pelvis during a golf swing. The coordination patterns were calculated using vector coding technique, which had been applied to quantify the coordination changes in coupling angle (γ) between two different segments. For this, fifteen professional and fifteen amateur golfers who had no significant history of musculoskeletal injuries. There was no significant difference in coordination patterns between the two groups for rotation motion during backswing (p = 0.333). On the other hand, during the downswing phase, there were significant differences between professional and amateur groups in all motions (flexion/extension: professional [γ] = 187.8°, amateur [γ] = 167.4°; side bending: professional [γ] = 288.4°, amateur [γ] = 245.7°; rotation: professional [γ] = 232.0°, amateur [γ] = 229.5°). These results are expected to be a discriminating measure to assess complex coordination of golfers' trunk movements and preliminary study for interesting comparison by golf skilled levels.     

Does intra-individual variability in narration matter and for what?

Building on calls to examine intra-individual variability in personality, we examined such variability in narrative. In Study 1, participants (n = 553) provided three narratives (either self-defining, turning point, transgression, low point, or trauma memories; n = 1659 narratives). Narratives were coded for coherence, autobiographical reasoning, resolution, and emotional expression. Variability was highest for resolution, lowest for coherence, and was related to well-being, depending on narrative feature and event type. In Study 2, participants (n = 103) engaged in a ‘narrative recognition’ task to see if they could identify which narratives came from the same individual. Recognizability was substantial, but not related to variability or well-being. Results showcase the importance of addressing intra-individual variability by narrative feature and event type.     

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.