Stress-induced salivary cortisol secretion during hypobaric hypoxia challenge and in vivo urinary thromboxane production in healthy male subjects

Few studies have assessed the effects of stress on in vivo platelet activation. In the present study, hypobaric hypoxia induced by rapid decompression during high-altitude simulated flight in a hypobaric chamber was used to evaluate the effects of environmental stress on salivary cortisol and urinary thromboxane metabolite (TXM) excretion, a noninvasive marker of in vivo platelet function. Twenty-one male aviators (mean ± SD age = 36 ± 7 years) experiencing hypoxia by removing their oxygen mask for 4-5 min during a simulated flight to 25,000 ft (7,620 m; pO(2) = 59.17 mmHg) and a matched control group of thirteen flying instructors wearing oxygen masks during the challenge, were studied. Hypobaric hypoxia induced a transient significant increase (P < 0.001) in the aviators' salivary cortisol concentration; the overall pattern of diurnal cortisol fluctuation was maintained in both groups. Urinary TXM showed a significant ～30% reduction (P < 0.01) after the chamber session in aviators exposed to hypobaric hypoxia, but not in controls. A significant inverse correlation was found between salivary cortisol and urinary TXM in aviators (r = - 0.64, P = 0.0015). Salivary cortisol was a significant predictor (P < 0.001) for urinary TXM concentrations in aviators. In conclusion, here we observed that an acute stress-induced salivary cortisol increase was associated with reduced urinary thromboxane biosynthesis, providing the first indirect evidence for an inhibitory effect of acute stress on in vivo platelet function.     

Understanding Continuity to Recognize Discontinuity

In this paper the author comments on the contribution by António P. Ribeiro and Miguel M. Gonçalves (in this journal) that offer a creative and unique perspective on maintenance and transformation of problematic self-narrative. From here the author contributes to the topic through the exploration of some issues: a) the relation, in the dialogical process of self-narrative construction, between semiotic processes that give voice to the semantic opposition and semiotic processes that give voice to the contradictory; b) the relation between sameness and ipseity in the self-narrative process; c) the role of a pathemic axis of meaning in the generation process of self-narratives. A final reflection is done on narrative as a device of clinical intervention in which the author makes a distinction between methods based on the recognition and extension of variability and methods based on the recognition of permanency so to get to variability.     

A Model of Intrinsic and Extrinsic Motivations on Subjective Well-Being: The Experience of Overnight Visitors to a National Park

According to the Self-Determination Theory (SDT) (Deci and Ryan 1985), intrinsic and extrinsic motivations can be differentiated with levels along a continuum representing distinct self-regulatory styles for behavior. Behavioral regulations consider different degrees to which they represent autonomous or self-determined functioning and specifically intrinsic motivations are characterized by the highest level of self-determination. Past research into the SDT has highlighted correlations between reasons with high levels of autonomy or self-determination for engaging in a particular behavior and enhanced Subjective Well-Being (SWB), as well as positive behavioral outcomes. Little is known about the relationship between visitors’ reasons for visiting a national park, associated self-regulatory styles and their self-appraisals of SWB. Therefore, the present research investigates the relationship between intrinsic and extrinsic motivations for visiting the Kruger National Park (KNP), associated self-regulatory styles and self-evaluations of SWB among 389 overnight visitors. A structural equation model (SEM) is proposed to examine both the cognitive (life satisfaction) and affective (positive and negative feelings) components of SWB in association to motivations with different degrees of self-determination. Reflecting previous research, the results show that overnight visitors who are more intrinsically motivated have higher life satisfaction levels, higher positive feelings and lower negative feelings. In contrast, overnight visitors who are less intrinsically motivated have lower life satisfaction levels, lower positive feelings and higher negative feeling. The practical implications of these findings are highlighted.     

Visuospatial working memory and mental representation of spatial descriptions

The purpose of the present research is to investigate whether different components of working memory (WM) are involved in processing spatial and nonspatial texts. The interference effects of two concurrent tasks on comprehension and recall of two kinds of text were investigated in two experiments. Each participant listened to a spatial and a nonspatial text, with one of two concurrent tasks: articulatory suppression or spatial tapping. The dependent variables in Experiment 1 were accuracy of recall and verification of information inferred from the texts. In Experiment 2 response times in the verification task were also considered. Results support the hypothesis that verbal and spatial components of working memory are differentially involved in the comprehension and memory of spatial and nonspatial texts, with a selective interference effect of the spatial concurrent task on the spatial text and an interference effect of the verbal concurrent task on both the spatial and nonspatial texts. These effects emerged for recall, sentence verification, and response times. Our findings confirm previous results showing that the verbal component of working memory is involved in the process of text comprehension and memory. In addition, they show that visuospatial working memory is involved, in so far as the text conveys visuospatial information.     

The cost of a strategy

Abstract

Experiment 1 demonstrated a new kind of dual-task interference effect. The primary task was a speeded left-right discrimination of stimulus position (R1). The un speeded secondary task consisted of reporting verbally whether the stimuli were the same or different (R2). Stimulus exposure time was either 150 or 2000 msec. Two groups of subjects performed the primary task only, whereas two other groups performed both tasks and were instructed to emit R1 before R2. It was reasoned that the decision would be made to emit R1 before R2, and that this decision would produce a lengthening of R1. The results supported this prediction. Experiment 2 showed that the interference effect also occurred when the subjects were not explicitly instructed to emit R1 before R2, and was not due to either the mere presence of the second task or to response grouping. Experiments 3 and 4 compared two possible models for explaining the interference effect, i.e. the capacity-sharing model and the postponement model. As predicted by the postponement model, task difficulty did not interact, or interacted underadditively, with task overlap (Experiment 3), and the interference effect was not influenced by the amount of processing resources devoted to the primary task (Experiment 4). It was concluded that this new type of interference effect is best explained by the version of the postponement model that locates the bottleneck at the decision stage.     

Put yourself in my wheelchair: Perspective-taking can reduce prejudice toward people with disabilities and other stigmatized groups

This study aimed to compare perspective-taking with a hypothetical target and perspective-taking occurring during a real interaction with an outgroup member in reducing prejudice toward people with disabilities and other groups (e.g., immigrants, homosexual people), via increased empathy. We adopted an experimental design with two treatment groups (Hypothetical target vs. Real target) and one control group (no intervention), one pretest and two posttest measures. Participants, who were 437 students aged 11–17 years (M = 14.28; SD = 1.17), were randomly assigned to the various conditions on a classroom basis. Perspective-taking was facilitated asking participants to travel in a wheelchair on a path that simulated a real pavement in the presence (or not) of an individual with a motor disability. Findings showed that perspective-taking in the presence of a real target was more effective in reducing prejudice toward people with disabilities than perspective-taking task without encountering an outgroup member. Perspective-taking with a hypothetical target was not sufficient to increase participants' empathy toward people with disabilities, which instead was enhanced when the task was performed at the presence of a real member of that group. Positive effects produced by perspective-taking (with both a hypothetical and a real target) were transferred to immigrants and homosexuals. These findings suggest that, when possible, perspective-taking in the presence of the target, which can improve empathy by favoring a two-way exchange process, is highly recommended to improve attitudes toward different stigmatized groups, not necessarily targeted by the intervention.     

Temperament and Character Inventory-R (TCI-R) and Big Five Questionnaire (BFQ): convergence and divergence

This study evaluated the correspondence between measures of two competing theories of personality, the five-factor model as measured by the Big Five Questionnaire (BFQ), and Cloninger's psychobiological theory measured by the Temperament and Character Inventory-Revised (TCI-R). A sample of 900 Italian participants, balanced with respect to sex (393 men and 507 women), and representative of the adult population with respect to age (range 18 to 70 years; M = 39.6, SD = 15.7) completed the TCI-R and the Big Five Questionnaire. All TCI-R personality dimensions except Self-Transcendence were moderately correlated with one or more of the Big Five dimensions (from r = .40 to .61), and the two instruments showed areas of convergence. However, the differences outweighed the similarities, indicating that these current conceptualizations and measures of personality are somewhat inconsistent with each other.     

The role of mental rotation and age in spatial perspective‐taking tasks: when age does not impair perspective‐taking performance

The relationship between self‐evaluation of sense of direction, mental rotation, and performance in map learning and pointing tasks has been investigated in a life‐span perspective. Study 1 compared younger and older people in the Mental Rotation Test (MRT) and on the Sense of Direction and Spatial Representation (SDSR) Scale. Older people achieved higher scores on the SDSR Scale, but a lower performance in MRT compared with younger participants. In Study 2, groups of younger and older adults, one of each, were matched in the MRT, and pointing tasks in aligned and counter‐aligned perspectives were administered. Our results showed that, when so matched, older participants performed better than the younger counterparts in perspective‐taking tasks, but their performance was worse in map learning. Aligned pointing was performed better than the counter‐aligned task in both age groups, showing an alignment effect. Furthermore the performance in the counter‐aligned pointing was significantly correlated with MRT scores. Copyright © 2006 John Wiley & Sons, Ltd.     

Holistic face processing can be independent of gaze behaviour: Evidence from the composite face illusion

People tend to perceive identical top halves (i.e. above the nose) of two face stimuli as being different when they are aligned with distinct bottom halves. This composite face illusion is generally considered as the most compelling evidence that facial features are integrated into a holistic representation. Here, we recorded eye‐movements during the composite face illusion in a delayed matching task of top halves of faces. Behavioural results showed a strong composite face effect, participants making more mistakes and taking longer time to match two identical top halves of faces when they were aligned (vs. misaligned) with different bottom halves. Importantly, fixation sites and eye‐movements were virtually identical when the top and bottom parts were aligned (composite illusion) or misaligned (no illusion), indicating that holistic face processing can be independent of gaze behaviour. These findings reinforce the view that holistic representations of individual faces can be extracted early on from information at a relatively coarse scale, independently of overt attention.     

Depressive personality styles, dysphoria, and social comparisons in everyday life

"Sociotropic" people are supposedly vulnerable to dysphoria after negative interpersonal events, whereas "autonomous" people are supposedly vulnerable to achievement-related failures. The present study examined whether these personality styles are borne out in social comparison processes. For 3 weeks, 27 sociotropic and 35 autonomous undergraduates completed records of their social comparisons. Depressive personality style moderated comparison frequency and the affective consequences of comparisons, especially for dysphoric individuals: Dysphoric respondents were especially likely to make comparisons in domains that were congruent with their personalities, and comparisons in congruent domains were associated with greater mood change than comparisons in other domains, perhaps especially for dysphoric respondents. These results have implications for the literatures on social comparison and on depressive personality styles.