Altered Arm-Body Coordination with Triggered Pointing Responses as Influenced by Task Predictability

Abstract

Reaching movements generate reaction forces that affect postural stability, requiring sophisticated coordination between body and arm movement to maintain balance. In voluntary movement, this coordination involves feedforward shifts of posture, and such anticipatory postural muscle activity also accompanies the rapid modulation of an ongoing point to suddenly a shifting target (double-step). However, it is unknown if this early postural activity depends on target-shift predictability and whether arm and body motion are similar coordinated to voluntary movement. Body and arm motion coordination during double-step pointing movements from standing were done under differing conditions of target-shift predictability. In a proportion of trials, the pointing target was displaced, with the predictability of target-shift direction varied between two peripheral targets (target-shift direction known) and two central targets (target-shift direction uncertain). The target jump evoked an adjustment in the arm then body response, opposite to the pointing responses to the initial target. The triggered arm-then-body ordering was consistent across target-shift predictability, although known target-shift direction resulted in closer timing of arm and body onsets. The altered coordination in triggered corrections suggests that the body component in triggered reactions depend on response predictability, showing an altered control of arm and body motion.     

Planned Straight or Biased to Be So? The Influence of Visual Feedback on Reaching Movements

Abstract

Behavioral studies consistently find that subjects move their hand along straight paths despite considerations that suggest reaches should be curved. Literature on this topic makes it clear that the experimentally displayed feedback influences how subjects reach. Could the standard visual feedback, a displayed cursor, explain the lack of path curvature in experimental results? To address this question, we conducted three experiments to examine reach behavior in the absence of the standard visual feedback. In the first experiment, we found significant increases in curvature as visual feedback was progressively extinguished across groups. A second experiment revealed that practiced reaches became curved after the standard visual feedback was removed. A final experiment found that subjects’ reaches made before and after a brief display of visual feedback were similar, indicating a preference for specific curved trajectories. Our results suggest that the consistently straight reaches often observed could be due to a bias to move the displayed cursor straight, which when removed reveal subject-specific preferences for reaches that are often curved.     

Effect of Stroke on Joint Control during Reach-to-Grasp: A Preliminary Study

Abstract

We investigated changes in control of inter-segmental dynamics underlying upper extremity dyscoordination caused by stroke. Individuals with stroke and healthy individuals performed a natural reach-to-grasp movement. Kinetic analysis revealed that both groups rotated the shoulder by muscle torque and used interaction torque to rotate the elbow. However, individuals with stroke used interaction torque less than healthy individuals, actively suppressing a substantial portion of it. This resulted in inefficient use of active control and dyscoordination of the upper extremity. The degree of interaction torque suppression and inefficiency of active control at the elbow positively correlated with stroke severity. The increased interaction torque suppression can be a strategy used by individuals with stroke to compensate for deficient feedforward control of this torque.     

New Fathers’ Perceptions of Dyadic Adjustment: The Roles of Maternal Gatekeeping and Coparenting Closeness

Although the association between maternal gatekeeping and relationship functioning has been explored by a few studies, none of these have focused on fathers’ perceptions of these constructs. Given that today's new fathers are challenged by elevated expectations for active parenting and coparenting even as most new mothers remain primary caregivers of infant children, this is a critical omission. This study examined the associations between new fathers’ perceptions of maternal gatekeeping and change in dyadic adjustment as mediated through coparenting closeness. Maternal gatekeeping was reported by 182 fathers at 3 months postpartum, coparenting closeness was reported at 3 and 6 months postpartum, and dyadic adjustment was reported during the third trimester of pregnancy and at 9 months postpartum. Fathers’ perceptions of relative change in coparenting closeness from 3 to 6 months mediated associations between fathers’ perceptions of maternal gatekeeping at 3 months and relative change in dyadic adjustment from the third trimester to 9 months postpartum. In particular, findings indicate that greater perceived maternal gate opening was associated with higher levels of dyadic adjustment through higher levels of coparenting closeness, whereas greater perceived maternal gate closing was associated with lower levels of dyadic adjustment through lower levels of coparenting closeness. This study highlights the importance of studying fathers in the context of the family system and the role of the coparenting relationship at the transition to parenthood in couple relationship functioning.     

Partial memory reinstatement while (lucid) dreaming to change the dream environment

Lucid dreams often coincide with having control over dream events in real-time, although the limitations of dream control are not completely understood. The current study probed the ability of lucid dreamers to reinstate waking scene memories while dreaming. After brief exposure to an experimental scene, participants were asked to reinstate the scene while lucid dreaming (i.e., change dream scenery to match real-world scene). Qualitative analysis revealed that successful dream scene reinstatements were overwhelmingly inaccurate with respect to the original experimental scene. Importantly, reinstatement inaccuracies held even when the dreamer was aware of them during the dream, suggesting a dissociation between memory access while dreaming and dream imagery. The ability to change the environment of a dream speaks to the high amount of lucid dream control, yet the inaccuracies speak to a lack of detailed control. Reinstating context during lucid sleep offers an experimental method to investigate sleep, dreams, and memory.     

Spouses' responses to the dietary nonadherence of their partners managing diabetes

The association between patients' dietary nonadherence and spouses' involvement in patients' diabetes diet was examined, with spouses' anxiety about nonadherence considered as a mediator of this association. Daily diary data from 128 older adult patients with type 2 diabetes and their spouses were analyzed using multilevel models. Results revealed that on days when patients reported less adherence to their diabetes diet than usual, spouses reported greater anxiety about patients' diabetes management, which, in turn, was related to greater spousal persuasion and pressure the same day. The association between patients' nonadherence and diet‐related support on the same day was not mediated, however, through spouses' anxiety. The findings contribute to an understanding of spouses' responses to patients' nonadherence to their diabetes regimen.     

Common mechanisms of executive attention underlie executive function and effortful control in children

Executive Function (EF) and Effortful Control (EC) have traditionally been viewed as distinct constructs related to cognition and temperament during development. More recently, EF and EC have been implicated in top‐down self‐regulation ‐ the goal‐directed control of cognition, emotion, and behavior. We propose that executive attention, a limited‐capacity attentional resource subserving goal‐directed cognition and behavior, is the common cognitive mechanism underlying the self‐regulatory capacities captured by EF and EC. We addressed three related questions: (a) Do behavioral ratings of EF and EC represent the same self‐regulation construct? (b) Is this self‐regulation construct explained by a common executive attention factor as measured by performance on cognitive tasks? and (c) Does the executive attention factor explain additional variance in attention deficit hyperactivity disorder (ADHD) problems to behavioral ratings of self‐regulation? Measures of performance on complex span, general intelligence, and response inhibition tasks were obtained from 136 preadolescent children (M = 11 years, 10 months, SD = 8 months), along with self‐ and parent‐reported EC, and parent‐reported EF, and ADHD problems. Results from structural equation modeling demonstrated that behavioral ratings of EF and EC measured the same self‐regulation construct. Cognitive tasks measured a common executive attention factor that significantly explained 30% of the variance in behavioral ratings of self‐regulation. Executive attention failed to significantly explain additional variance in ADHD problems beyond that explained by behavioral ratings of self‐regulation. These findings raise questions about the utility of task‐based cognitive measures in research and clinical assessment of self‐regulation and psychopathology in developmental samples.     

Approaching to a structural model of impulsivity and driving anger as predictors of risk behaviors in young drivers

Due to the high rates of traffic accidents in young drivers, psychology studies identify road anger as an important factor associated to risk driving behaviors, in order to know which psychological variables can predict road anger, the literature suggest impulsivity as an individual condition related to anger. The objective of this research is to obtain an explanatory model of risk driving as a result of the relationship of impulsivity, road anger expression and the control of impulsivity and anger. A sample of 407 subjects, both sexes drivers were surveyed, obtaining a structural equation model with acceptable adjustment values. The model showed that control of impulsivity and anger predict impulsivity (β = −0.25) and physical expression of anger (β = −0.50), Impulsivity also showed predictive capacity towards the physical expression of anger (β = 0.29), and the physical expression of anger towards risk driving behaviors (β = 0.89). Due to the findings it is suggested the implementation of social programs that promote the development of anger regulatory skills and impulse control, as part of the preventive actions of road accidents.     

Relationship between the internal locus of control and collective action: A comparison of East Asian and Western Countries

This study tested factors related to collective action in East Asian and Western countries. Although the social identity model of collective action (SIMCA) could explain which factors relate to collective action in Western countries, previous studies have found that some of the SIMCA variables did not predict collective action in non‐Western countries. We hypothesised that the internal locus of control would be positively related to collective action even in East Asian countries because previous studies have demonstrated that the former can positively influence proactive behaviour when factors inhibiting such behaviours exist. We analysed the 2010 World Values Survey data from seven countries (three East Asian and four Western countries). The results demonstrated that the internal locus of control was positively related to collective action more so among East Asians (Koreans, specifically those with low political interests, the Taiwanese, and Japanese people with lower income) than among Westerners. These results suggest that the internal locus of control is a key individual difference that predicts collective action in the presence of factors that inhibit such participation (e.g., cultural values, low political interest, and low income).     

Intention of Chinese college students to use carsharing: An application of the theory of planned behavior

Carsharing originated in Europe and then expanded to developed countries such as the United States. With the revival and popularity of the “Sharing Economy,” carsharing has remarkably increased in China in recent years. Carsharing has increased convenience for individuals without private cars and is changing the traditional view of car ownership. Chinese college students are a large, highly educated group with low incomes and low rates of car ownership. Understanding the determinants of Chinese college students' intention to carshare is critical to promote carsharing services. In this research, an expanded version of the theory of planned behavior, which contains environmental concern, is the theoretical research framework. The model was empirically tested by using the questionnaire data of 356 college students from four universities in Qingdao, China. The results indicate that subjective norm and the perceived behavioral control are directly and positively associated with Chinese college students’ intention to use carsharing, and attitude and environmental concern have no direct correlation with the intention. Environmental concern has a significant direct effect on attitude, subjective norm, and perceived behavioral control. In addition, environmental concern indirectly impacts Chinese college students’ intention to use carsharing through subjective norm and perceived behavioral control. The findings yield practical insights for carsharing organizations and transportation planners. Based on these results, limitations of this study and suggestions for further research are discussed.