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961.
The influence of match length and re-matching on the effectiveness of school-based mentoring was studied in the context of a national, randomized study of 1,139 youth in Big Brothers Big Sisters programs. The sample included youth in grades four through nine from diverse racial and ethnic backgrounds. At the end of the year, youth in intact relationships showed significant academic improvement, while youth in matches that terminated prematurely showed no impact. Those who were re-matched after terminations showed negative impacts. Youth, mentor, and program characteristics associated with having an intact match were examined. Youth with high levels of baseline stress and those matched with college student mentors were likely to be in matches that terminated prematurely, while rejection-sensitive youth and mentors who had previous mentoring experience were more likely to be in intact relationships. Implications for research and practice are discussed.  相似文献   
962.
In four experiments, task-switching processes were investigated with variants of the alternating runs paradigm and the explicit cueing paradigm. The classical diffusion model for binary decisions (Ratcliff, 1978) was used to dissociate different components of task-switching costs. Findings can be reconciled with the view that task-switching processes take place in successive phases as postulated by multiple-components models of task switching (e.g., Mayr & Kliegl, 2003; Ruthruff, Remington, & Johnston, 2001). At an earlier phase, task-set reconfiguration (Rogers & Monsell, 1995) or cue-encoding (Schneider & Logan, 2005) takes place, at a later phase, the response is selected in accord with constraints set in the first phase. Inertia effects (Allport, Styles, & Hsieh, 1994; Allport & Wylie, 2000) were shown to affect this later stage. Additionally, findings support the notion that response caution contributes to both global as well as to local switching costs when task switches are predictable.  相似文献   
963.
The law of prior entry states that attended objects come to consciousness more quickly than unattended ones. This has been well established in spatial cueing paradigms, where two task-relevant stimuli are presented near-simultaneously at two different locations. Here, we suggest that prior entry also plays a pivotal role in temporal attention paradigms, where stimuli appear at the same location but at distinct moments in time, in rapid serial presentation (RSVP). Specifically, we hypothesize that prior entry can explain temporal order reversals in reporting two targets from RSVP. In support of this, three experiments show that cueing attention toward either of the targets has a strong influence on order errors. We conclude that prior entry provides a viable explanation of the way in which relevant information is prioritized in RSVP.  相似文献   
964.
The authors test the hypothesis that low-effort thought promotes political conservatism. In Study 1, alcohol intoxication was measured among bar patrons; as blood alcohol level increased, so did political conservatism (controlling for sex, education, and political identification). In Study 2, participants under cognitive load reported more conservative attitudes than their no-load counterparts. In Study 3, time pressure increased participants' endorsement of conservative terms. In Study 4, participants considering political terms in a cursory manner endorsed conservative terms more than those asked to cogitate; an indicator of effortful thought (recognition memory) partially mediated the relationship between processing effort and conservatism. Together these data suggest that political conservatism may be a process consequence of low-effort thought; when effortful, deliberate thought is disengaged, endorsement of conservative ideology increases.  相似文献   
965.
Mentally contrasting a desired future with impeding reality promotes goal pursuit when expectations of success are high and curbs goal pursuit when expectations of success are low. Four studies tested whether mental contrasting affects responses to goal-relevant negative feedback. Mental contrasting promoted the processing of negative feedback (Studies 1 and 2), which in turn helped participants to form plans beneficial for goal pursuit (Study 2). Mental contrasting also protected the self-view of competence against negative feedback (Study 3) and facilitated beneficial attributions for negative feedback (Study 4). All effects occurred in line with expectations of success. These results suggest that mental contrasting regulates effective responses to negative feedback by bringing goal pursuit in line with expectations of success.  相似文献   
966.
Drop-jumps are controlled by predictive and reactive motor strategies which differ with respect to the utilization of sensory feedback. With reaction, sensory feedback is integrated while performing the task. With prediction, sensory information may be used prior to movement onset. Certainty about upcoming events is important for prediction. The present study aimed at investigating how uncertainties in the task execution affect predictive motor control in drop-jumps. Ten healthy subjects (22±1 years, M±SD) participated. The subjects performed either (i) drop-jumps by knowing that they might had to switch to a landing movement upon an auditory cue, which was sometimes elicited prior to touch-down (uncertainty). In (ii), subjects performed drop-jumps by knowing that there would be no auditory cue and consequently no switch of the movement (certainty). The m. soleus EMG prior to touch-down was higher when subjects knew there would be no auditory cue compared to when subjects performed the same task but switching from drop-jump to landing was possible (uncertainty). The EMG was reversed in the late concentric phase, meaning that it was higher in the high uncertainty task. The results of the present study showed that the muscular activity was predictively adjusted according to uncertainties in task execution. It is argued that tendomuscular stiffness was the variable responsible for the adjustment of muscular activity. The required tendomuscular stiffness was higher in drop-jumps than in landings. Consequently, when it was not certain whether to jump or to land, muscular activity and therefore tendomuscular stiffness was reduced.  相似文献   
967.
Increasing amounts of data are collected in sports due to technological progress. From a typical soccer game, for instance, the positions of the 22 players and the ball can be recorded 25 times per second, resulting in approximately 135.000 datasets. Without computational assistance it is almost impossible to extract relevant information from the complete data. This contribution introduces a hierarchical architecture of artificial neural networks to find tactical patterns in those positional data. The results from the classification using the hierarchical setup were compared to the results gained by an expert manually classifying the different categories. Short and long game initiations can be detected with relative high accuracy leading to the conclusion that the hierarchical architecture is capable of recognizing different tactical patterns and variations in these patterns. Remaining problems are discussed and ideas concerning further improvements of classification are indicated.  相似文献   
968.
Several studies have used variability of continuous relative phase (CRP) to investigate overuse injuries, since low variability is thought to be related to running injuries. This study investigates whether the analysis of CRP variability leads to additional information about possible differences or similarities between healthy and injured runners. Further, a decision about future applications of CRP variability should be based on the ability to implement and interpret data. 18 healthy female runners (CO) and 18 female runners who suffered from iliotibial band syndrome (ITBS) were evaluated by calculating CRP variability for 4 coupling pairs. Besides analyzing continuous variability of CRP, we also averaged it for the whole stance phase and for four predefined stance phase intervals. Confidence intervals were displayed and independent t-tests for comparing the two groups were conducted. During initial and terminal stance phase as well as after heel-off an increase in CRP variability was detected for both groups of runners. In contrast, the foot flat period was characterized by stable joint coordination and a decrease in variability. This paper presents possible interpretations of CRP variability but no statistically significant differences in CRP variability were found between the two groups of runners. Despite the missing statistical significance, a relationship between high CRP variability and injury seems to be conceivable, since the injured runners demonstrated an increased variability for all couplings in the first half of the stance phase. Further application of CRP variability in biomechanical research is essential to determine whether a relationship exists between injury and coordination variability.  相似文献   
969.
Previous findings concerning the relation of risk aversion and cooperation in repeated prisoner's dilemma games have been inconclusive. We hypothesized that this was due to an interaction between personality and environment. Specifically, we argued that in cooperation-friendly environments--given certain beliefs--defection is more risky than cooperation. The main reason for this is that, in such a situation, defection potentially yields outcomes of higher variance (and vice versa, for cooperation-unfriendly environments). In line with this hypothesis, we showed, in two experiments and a reanalysis of a study by Fudenberg, Rand, and Dreber (American Economic Review, in press), that the degree of cooperation increases with dispositional risk aversion in cooperation-friendly environments, but not in cooperation-unfriendly environments. We also found similar person-situation interactions for neuroticism and extraversion.  相似文献   
970.
In two experimental studies we found that participants who recalled a highly traumatic autobiographical event (trauma recall) compared with a lesser traumatic event (stress recall) reported having increasingly grown (posttraumatic growth, PTG). Moreover, participants who recalled a traumatic (vs. stressful) event perceived more death-related thoughts (Study 1) and reported coping with this event in a more emotion-focused and in a less problem-focused way (Study 2). Mediation analyzes revealed that the effect of trauma versus stress recall on PTG was mediated by emphasizing the positive, a subscale of emotion-focused coping. These results imply that growth resulting from traumatic events can be traced back to an illusion. No evidence was found that real PTG took place or that the effects shown resulted from death-related thoughts (terror management theory).  相似文献   
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