Differentiated ratings of perceived exertion and physiological responses during aerobic dance steps by impact/type of arm movement

Overall ratings of perceived exertion, i.e., undifferentiated RPE, are often used as indicators of exercise intensity during walking, jogging, and cycling; however, conflicting results concerning RPE during aerobic dance exercise have been reported, and the use of differentiated RPE, i.e., local RPE and central RPE, has not been investigated. The purposes of this study were to assess local, central, and over-all RPE, and physiological responses [heart rate (HR); % HRmax; absolute and relative VO2;% VO2 max, ventilation (VE), ventilatory equivalent (VE.VO2(-1); and oxygen pulse] during aerobic dance exercise varied by Arm Movement (Static Arm vs Dynamic Arm) and Impact (High vs Low). Trained women (N = 25; max VO2 = 50.4 +/- 7.5 ml.kg-1.min.-1) completed four aerobic dance steps. No RPE were significantly correlated with heart rate or VO2; however, for all steps all RPE were significantly (r = .40-.62) correlated with VE.VO2(-1) or VE. No interactions were present for RPE or physiological variables, and main effects were noted for Impact and Arm Movement. All RPE were greater for High Impact and for Static Arm Movement. Because VE and VE.VO2(-1) were correlated with Overall RPE for all steps, this may suggest that participants "attended to" perceived changes in respiratory phenomena during aerobic dance exercise. It appears that during combined arm-and-leg aerobic dance exercise the use of Overall RPE is sufficient to assess perceptual sensations associated with the intensity of the exercise. Changes in Overall RPE were proportionate to objective measures of exercise intensity, i.e., HR and VO2; however, it is recommended that both HR and Overall RPE be used to assess fully a participant's objective and subjective responses during aerobic dance exercise.     

Cytokine responses to LTP induction in the rat hippocampus: a comparison of in vitro and in vivo techniques

Because exogenous application of a number of cytokines and growth factors can alter synaptic properties, we sought to determine if endogenous cytokine expression is affected by neuronal activity. In addition, we examined whether cytokine expression is altered by the techniques used to stimulate and record from hippocampal neurons. Using semi-quantitative RNase protection and RT-PCR assays, we studied the expression of 18 cytokine, growth factor, and receptor genes in the hippocampus following the induction of Schaffer collateral-CA1 long-term potentiation (LTP). We found that various cytokines are dramatically induced following preparation of slices for in vitro recording and as a result of injury following acute electrode placement in vivo. These increases can be overcome in vivo, however, using permanent electrodes implanted three weeks prior to testing. Using this chronic preparation, we found that interleukin-6 (IL-6) mRNA was upregulated nearly 20-fold by LTP induction in vivo, marking the first demonstration of endogenous regulation of this cytokine in response to LTP. In situ hybridization for IL-6 revealed that upregulation is tightly localized near the site of stimulation and is detected only in non-neuronal cells, identified as GFAP+ astrocytes and GFAP− cells within proximal blood vessels. Coupled with previous results showing that exogenously applied IL-6 can prevent the induction of LTP, this finding suggests a mechanism by which the local release of a cytokine could regulate LTP at nearby sites.     

Is the good life characterized by self-control? Perceived regulatory success and judgments of life quality

To what extent do people view self-control as central to achieving a healthy, high-quality life? While scientific evidence strongly supports the notion that self-control is associated with successful adaptation and optimal functioning, we examine whether individuals connect this trait with positive outcomes. In Study 1, participants rated the likelihood that an individual with high self-control (or self-esteem) would experience good health and a high-quality life. Studies 2–3 experimentally portrayed a target person as high or low in self-control (and self-esteem) before participants rated the target on an array of positive outcomes. Across studies, self-control was perceived as less strongly connected with a high-quality life than self-esteem. Mediation analyses suggest that people link self-esteem (but not self-control) with healthy behaviors that, in turn, lead to superior perceived physical and psychological health. While self-esteem is strongly associated with lay concepts of the good life, the importance of self-control may be comparatively under-recognized.     

Visual marking: the influence of temporary changes on time-based visual selection

The preview benefit describes the finding that participants can prioritize the selection of new stimuli by the top-down inhibition of previously presented (previewed) items already in the field (Watson & Humphreys, 1997). Previous work has shown that if the old items undergo a permanent shape change when the new are added, then the old items recompete for selection with the new-the preview benefit is abolished. This is adaptive because it would be useful to stop ignoring items which change in potentially important ways. In contrast, temporary or repeating changes might be much less behaviorally relevant than permanent changes. Accordingly, we examined the effect of temporary changes (Experiment 1) and repeating changes (Experiment 2). Overall, the results showed that temporary changes could be partially but not fully ignored, and ignoring repeating changes became more difficult as the number of repetitions increased. The findings are discussed in terms of attentional prioritization mechanisms, maintenance of inhibitory representations, and the ecological properties of time-based selection.     

Peritraumatic dissociation mediates the relationship between acute panic and chronic posttraumatic stress disorder

Although peritraumatic dissociation predicts subsequent posttraumatic stress disorder (PTSD), little is understood about the mechanism of this relationship. This study examines the role of panic during trauma in the relationship between peritraumatic dissociation and subsequent PTSD. Randomized eligible admissions to 4 major trauma hospitals across Australia (n = 244) were assessed during hospital admission and within one month of trauma exposure for panic, peritraumatic dissociation and PTSD symptoms, and subsequently re-assessed for PTSD three months after the initial assessment (n = 208). Twenty (9.6%) patients met criteria for PTSD at 3-months post injury. Structural equation modeling supported the proposition that peritraumatic derealization (a subset of dissociation) mediated the effect of panic reactions during trauma and subsequent PTSD symptoms. The mediation model indicated that panic reactions are linked to severity of subsequent PTSD via derealization, indicating a significant indirect relationship. Whereas peritraumatic derealization is associated with chronic PTSD symptoms, this relationship is influenced by initial acute panic responses.     

Effects of age on searching for and enumerating targets that cannot be detected efficiently

We investigated the effects of old age on search, subitizing, and counting of difficult-to-find targets. In Experiment 1, young and older adults enumerated targets (Os) with and without distractors (Qs). Without distractors, the usual subitization-counting function occurred in both groups, with the same subitization span of 3.3 items. Subitization disappeared with distractors; older adults were slowed more overall by their presence but enumeration rates were not slowed by ageing either with or without distractors. In contrast, search rates for a single target (O among Qs) were twice as slow for older as for young adults. Experiment 2 tested and ruled out one account of age-equivalent serial enumeration based on the need to subvocalize numbers as items are enumerated. Alternative explanations based on the specific task differences between detecting and enumerating stimuli are discussed.     

The Effect of Stimulus Preexposure on Responding during a Compound Stimulus

In two experiments with rats, three stimuli, A, B, and X, were used for an AX+ BX+ Xo discrimination in which food was presented after the simultaneous presentation of A and X, or B and X, but never after X by itself. For one group in each experiment, X was repeatedly presented by itself before the start of discrimination training. This manipulation weakened responding on test trials in which the three stimuli were presented together. The results are interpreted in terms of a configural theory of conditioning that assumes that preexposure to a stimulus will reduce its capacity to promote generalization among different configurations to which it belongs.