Kinematic property of target motion conditions gaze behavior and eye-hand synergy during manual tracking

This study investigated how frequency demand and motion feedback influenced composite ocular movements and eye-hand synergy during manual tracking. Fourteen volunteers conducted slow and fast force-tracking in which targets were displayed in either line-mode or wave-mode to guide manual tracking with target movement of direct position or velocity nature. The results showed that eye-hand synergy was a selective response of spatiotemporal coupling conditional on target rate and feedback mode. Slow and line-mode tracking exhibited stronger eye-hand coupling than fast and wave-mode tracking. Both eye movement and manual action led the target signal during fast-tracking, while the latency of ocular navigation during slow-tracking depended on the feedback mode. Slow-tracking resulted in more saccadic responses and larger pursuit gains than fast-tracking. Line-mode tracking led to larger pursuit gains but fewer and shorter gaze fixations than wave-mode tracking. During slow-tracking, incidences of saccade and gaze fixation fluctuated across a target cycle, peaking at velocity maximum and the maximal curvature of target displacement, respectively. For line-mode tracking, the incidence of smooth pursuit was phase-dependent, peaking at velocity maximum as well. Manual behavior of slow or line-mode tracking was better predicted by composite eye movements than that of fast or wave-mode tracking. In conclusion, manual tracking relied on versatile visual strategies to perceive target movements of different kinematic properties, which suggested a flexible coordinative control for the ocular and manual sensorimotor systems.     

Childhood Abuse and Neglect in an Outpatient Clinical Sample: Prevalence and Impact

The study examined the prevalence of five types of childhood trauma in a sample of adult clients (n = 497) as well as their long-term relation to trauma symptoms in adulthood. Results showed a high prevalence of abuse and neglect with emotional abuse and neglect being the most common ones. Emotional abuse was the best and strongest predictor of trauma symptoms in adulthood, including anxiety, depression, defensive avoidance, as well as internal confusion and emptiness. The results indicated that experience of emotional abuse is no less significant than that of physical and sexual abuse in its long-term impact. Clinical implication was provided.     

The Association Between Adult Attachment Styles and Conflict Resolution in Romantic Relationships

This study examined whether adult attachment was predictive of conflict resolution behaviors and satisfaction in romantic relationships. It adopted a two-dimensional conceptualization for both adult attachment style (model of self, model of others) and conflict resolution behaviors (concern for self, concern for others). Both adult attachment dimensions, Avoidance and Anxiety, were predictive of conflict resolution behaviors and relationship satisfaction. Gender differences existed in conflict resolution behaviors, but they were not as strong a predictor as attachment characteristics of conflict resolution and relationship satisfaction. No gender differences were found in attachment styles.     

Team–Member Exchange and Work Engagement: Does Personality Make a Difference?

Purpose

Adopting a person–situation interactionist framework, this study examined the joint effects of employee personality (i.e., extraversion, neuroticism, and conscientiousness) and social exchange relationships with peers (i.e., team–member exchange; TMX) in predicting work engagement.

Methodology

This study is based on survey responses from 235 Chinese employees collected at two time points with 3 months in between. We conducted moderated regression analyses to test the hypotheses that employees higher in extraversion or conscientiousness or lower in neuroticism would demonstrate a stronger TMX–work engagement relation.

Findings

Results from this study showed that the three focal personality traits moderated the TMX–engagement relation simultaneously. Specifically, the positive TMX–engagement relation was stronger for employees with higher extraversion or lower neuroticism than that for their counterparts. Interestingly, the TMX–engagement relation was positive for employees lower in conscientiousness but negative for those higher in conscientiousness.

Implications

These findings support the notion that lateral social exchange relationships in the workplace (i.e., TMX) are an important antecedent of work engagement and, more importantly, their beneficial effects on work engagement are contingent on certain types and/or levels of personality traits.

Originality/Value

This study not only advances our understanding of presumed antecedents of work engagement but also opens a new door for future research on work engagement by highlighting the importance of a person–situation interactionist framework.     

Dynamic Regulation Responding to an External Stimulus: A Differential Equation Model

This study examines the dynamic regulation process responding to an external stimulus. The damped oscillator model has been used to describe this process. However, the model does not allow a nonzero steady state, even though the oscillations may continue and do not necessarily damp toward zero. This study introduces the driven damped oscillator model which has an additional parameter to identify different patterns of the steady state. Three methods, generalized local linear approximation, continuous time structural equation modeling, and analytic solutions of differential equations are provided to estimate model parameters. A simulation study indicates that parameters in the driven damped oscillator model are well recovered. The model is then illustrated using a data set on the daily reports of sales after a sale promotion. Potential applications and possible expansions of this model are also discussed.     

Detecting Misspecified Multilevel Structural Equation Models with Common Fit Indices: A Monte Carlo Study

This study investigated the sensitivity of common fit indices (i.e., RMSEA, CFI, TLI, SRMR-W, and SRMR-B) for detecting misspecified multilevel SEMs. The design factors for the Monte Carlo study were numbers of groups in between-group models (100, 150, and 300), group size (10, 20, 30, and 60), intra-class correlation (low, medium, and high), and the types of model misspecification (Simple and Complex). The simulation results showed that CFI, TLI, and RMSEA could only identify the misspecification in the within-group model. Additionally, CFI, TLI, and RMSEA were more sensitive to misspecification in pattern coefficients while SRMR-W was more sensitive to misspecification in factor covariance. Moreover, TLI outperformed both CFI and RMSEA in terms of the hit rates of detecting the within-group misspecification in factor covariance. On the other hand, SRMR-B was the only fit index sensitive to misspecification in the between-group model and more sensitive to misspecification in factor covariance than misspecification in pattern coefficients. Finally, we found that the influence of ICC on the performance of targeted fit indices was trivial.     

Interactions between interfacial dislocations and γ/γ′ interface during high temperature – low stress creep in nickel-based single crystal superalloy

ABSTRACT

The interaction between interfacial dislocations and γ/γ′ interface is critical to the high temperature creep properties of single crystal superalloys. However, only a few studies have paid attention to the detailed structure such as local interfacial morphologies and the elemental distribution around interfacial dislocations. In this paper, the interfacial protrusions and related dislocations in a single crystal superalloy after creep at high temperature – low stress have been investigated in detail. It is found that the morphology and size of the interfacial protrusions remain almost the same during the early and middle stages of high temperature creep, which indicates a local equilibrium at the interfacial protrusions. Steps at different height are formed at the γ/γ′ interface at the initial stage of high temperature creep since dislocations could move along the γ/γ′ interface, which indicates that dislocation motion at different creep stage may affect the morphology of γ/γ′ interface.     

Sedimentation of substitutional atoms and phase change in an In-Pb alloy under an ultrastrong gravitational field

It was found that an atomic-scale graded structure was formed, and a phase change occurred, in an In–Pb alloy by the sedimentation of substitutional solute atoms under an ultrastrong gravitational field (820?000?g (maximum); 150°C; 100?h). Continuous gradients in the concentration of Pb (from about 6 to 45?at.%) and In (from about 94 to 55?at.%) and resulting changes in the lattice constant were observed. Fcc (Pb-rich) and tetragonal (In-rich) phases appeared in the strong- and weak-gravity regions respectively from a single starting fct α phase. It is suggested that sedimentation of substitutional atoms can be used to control the compositions and structure of bulk materials and also thin films or layer interfaces.     

Capturing and evaluating blinks from video-based eyetrackers

Blinks are related to several emotional states, and the present report describes a simple, reliable way to measure blinks from the video stream of an eye obtained during eyetracking, where the source of the eye video is a video camera attached to a head-mounted eyetracker. Computer vision techniques are employed to determine the moments that a blink starts and ends, for the purpose of calculating blink frequency and duration. The video is first processed to show blocks of eyelid and pupil movements, and is then analyzed for blink starts and ends. The moment of a blink start is reported when the eyelid starts to move quickly, exceeding a predetermined threshold. The end of a blink arises when the pupil size increases by less than a separate threshold. We observed several different blink patterns from different subjects, and our algorithm was designed to work for all of these patterns. We evaluated our algorithm by manually measuring the true blinks of five different subjects while they were eyetracked. To test the sensitivity and specificity of the algorithm, we employed a series of threshold values to plot the receiver operating characteristic curves. Using the best thresholds, we achieved excellent sensitivity (>90 %) and specificity (>99 %) over the five subjects. Potential applications of this research include real-time, nonintrusive, continuous and automated measurements of mental workload and other emotional states related to blink rates and durations.