Effect of localized muscle fatigue on vertical ground reaction forces and ankle joint motion during running

The purpose of this study was to examine the changes in the vertical ground reaction force (VGRF) and ankle joint motion during the first 50% of the stance phase of running following fatiguing exercise of either the dorsiflexors or the invertors of the foot. VGRFs, sagittal and rearfoot kinematic data were collected from 11 female recreational runners running at 2.9 m/second on a treadmill prior to and following localized muscle fatigue of either the invertors or dorsiflexors of the right foot. Loading rate of the impact peak force significantly increased following fatiguing exercise of the dorsiflexors, while the peak magnitudes of the impact and push-off forces remained unchanged. There were significant decreases in dorsiflexion at heel contact, but no significant difference in any rearfoot motion parameters tested following dorsiflexor fatigue. Following fatiguing exercise of the invertors, impact peak magnitude, push-off peak magnitude and the rate of decline of the impact peak force significantly decreased; there was no change in the loading rate of the impact peak force. Invertor fatigue also resulted in a less inverted foot position at heel contact, but there were no significant differences in any other kinematic parameters tested. The results demonstrate that localized muscle fatigue of either the invertors or dorsiflexors can have a significant effect on the loading rates, peak magnitudes and ankle joint motion seen during running. These changes, due to localized muscle fatigue, may play a role in many common lower extremity running injuries.     

Time is of the essence

Timing is essential to human behaviour, but the neural mechanisms underlying time perception are still unclear. New findings from a brain-imaging study by Coull et al. show that activity in a network of motor-related areas varies parametrically with attention to time. Given that a system in which timing is important (but not the primary function) is recruited when temporal judgements are required, we should perhaps reassess the notion of a dedicated timing system in the brain.     

An experimental investigation of daytime monitoring for sleep-related threat in primary insomnia

An experimental manipulation was conducted to test the hypothesis that monitoring for sleep-related threat during the day triggers a cycle of cognitive processes that includes increased negative thinking, increased use of safety behaviours, increased perceived impairment in functioning, and increased self-reported sleepiness. Forty-seven individuals with primary insomnia were randomly assigned to a monitoring group (instructed to monitor their body sensations), a no-monitoring group (instructed to distract from their body sensations), or a no-instruction group. The manipulations to monitor or not monitor were administered immediately on waking and participants were asked to continue the manipulation throughout the experimental day. The monitoring group reported more negative thoughts, the use of more safety behaviours, and more sleepiness during the day relative to the no-instruction group. These findings offer support to a recent cognitive model, which identifies daytime monitoring for sleep-related threat as a key factor in the maintenance of the daytime distress and difficulty functioning in chronic insomnia.     

Priming a natural or human-made environment directs attention to context-congruent threatening stimuli

Research suggests that attention is attracted to evolutionary threats (e.g., snakes) due to an evolved “fear-module” that automatically detects biological threats to survival. However, recent evidence indicates that non-evolutionary threats (e.g., guns) capture and hold attention as well, suggesting a more general “threat-relevance” mechanism that directs attentional resources toward any potential danger in the environment. The current research measured how selective attentional resources were influenced both by the type of threat (e.g., snake vs. gun) and by the context in which the threat was encountered. Participants were primed with either natural or human-made environments to assess how these contexts influence attention to evolutionary and non-evolutionary threats, as measured by a spatial-cueing task. The results indicate that whether biological or non-biological threats receive greater attentional processing is determined by the context in which they are encountered.     

“So wat do u want to wrk on 2day?”: The Ethical Implications of Online Counseling

Internet counseling is an area of rapid expansion in the field of applied psychology. Internet counseling or psychotherapy involves a variety of activities such as psychoeducation, individual therapy, and automated self-help interventions delivered via the Internet. Although other professional societies such as the National Association of Social Workers, the American Counseling Association, and the National Board of Certified Counselors have tackled the issues of Internet counseling ethics head on, the American Psychological Association has been conspicuously absent from this debate. Yet online therapy clinics are operating, and intervention efficacy is being studied. This discussion provides an overview of online counseling modalities, details the ethical concerns associated with each, and offers suggestions for the ethical practice of online counseling.     

How to stop binge drinking and speeding motorists: Effects of relational-interdependent self-construal and self-referencing on attitudes toward social marketing

How can marketers stop speeding motorists and binge drinking? Two experiments show that the beliefs consumers have about the degree to which they define themselves in terms of their close relationships (i.e., relational-interdependent self-construal (RISC)) offer useful insights into the effectiveness of communications for two key social marketing issues—road safety (Study 1, New Zealand sample) and alcohol consumption (Study 2, English sample). Further, self-referencing is a mechanism for these effects. Specifically, people who define themselves in terms of their close relationships (high-RISCs) respond most favorably to advertisements featuring a dyadic relationship (two people), and this favorable response is mediated by self-referencing. In contrast, people who do not include close relationships in their sense of self (low-RISCs) respond most favorably to self-reference advertisements featuring solitary models. Copyright © 2013 John Wiley & Sons, Ltd.     

The Effect of Movement Amplitude and Target Diameter on Reaction Time

Siegel’s (1977) interpretation that his reaction time results were solely a function of response factors (movement amplitude and target diameter) was discussed and criticized. It was argued that Siegel’s interpretation was inappropriate because stimulus factors (eccentric and visual angle) and response factors were confounded. It was also argued that the surprising U-shaped relation between reaction time and movement amplitude was probably the result of the confounding between stimulus and response factors.     

The Learning of Programmed- and Feedback-Based Processes Controlling the Production of a Positioning Response in Two Dimensions

Two experiments were conducted to investigate the learning of the programmed- and feedback-based processes controlling the production of a slow, self-paced positioning response in two dimensions (direction and extent) in the horizontal plane. Both experiments had two phases: an acquisition phase of 60 trials with KR, followed by a KR withdrawal phase of 20 trials. In Experiment 1, one group (N=15) had visual feedback about the ongoing movement and the other group (N=15) did not. In Experiment 2, one group (N=15) practiced initiating the response in the criterion direction and moving the criterion extent, whereas, the other group (N=15) practiced initiating the response in the criterion direction and moving randomly varied extents. The results of Experiment 1 indicated that the learning of a programmed-based process is a gradually acquired freedom from visual feedback. Experiment 2 revealed that a programmed-based process can be learned independent of a feedback-based process.     

Perceptions of adolescent bullying: Attributions of blame and responsibility in cases of cyber‐bullying

Cyber‐bullying (where victims are targeted via online social networking or other electronic means) has gained increased attention in research and the broadcast media, but previous research has not investigated attribution of blame in such cyber‐bullying events. This experiment hypothesized that participants would assign higher ratings of blame to bullying perpetrators when the bullying situations were depicted as having highly foreseeable outcomes (vs. unforeseeable outcomes), and as occurring in school (vs. online). In addition, a significant interaction was predicted between outcome foreseeability and bullying situation, with highly foreseeable in‐school events being rated as the most predictable and attributable to the bully's actions. One‐hundred sixty‐three participants completed surveys containing demographic items, items regarding their past experiences of victimization, and one of four randomly‐assigned vignettes detailing a bullying situation (which participants rated). While hypotheses regarding outcome foreseeability were supported, no cyber‐bullying vs. in‐school main effects (or corresponding interaction effects) were detected. Implications for future research and practice, as well as study limitations, are discussed.