Distorted symptom perception in patients with medically unexplained symptoms.

The present study investigated differences in symptom perception between a clinical sample with medically unexplained symptoms (MUS) and a matched healthy control group. Participants (N = 58, 29 patients) were told that they would inhale different gas mixtures that might induce symptoms. Next, they went through 2 subsequent rebreathing trials consisting of a baseline (60 s room air breathing), a rebreathing phase (150 s, which gradually increased ventilation, PCO2 in the blood, and perceived dyspnea), and a recovery phase (150 s, returning to room air breathing). Breathing behavior was continuously monitored, and dyspnea was rated every 10 s. The within-subject correlations between dyspnea on the one hand and end-tidal CO2 and minute ventilation on the other were used to index the degree to which perceived dyspnea was related to specific relevant respiratory changes. The results showed that perceived symptoms were less strongly related to relevant physiological parameters in MUS patients than in healthy persons, specifically when afferent physiological input was relatively weak. This suggests a stronger role for top-down psychological processes in the symptom perception of patients with MUS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in unipolar depression: Evidence and theory.

A large body of evidence indicates that women are more likely than men to show unipolar depression. Five classes of explanations for these sex differences are examined and the evidence for each class is reviewed. Not one of these explanations adequately accounts for the magnitude of the sex differences in depression. Finally, a response set explanation for the sex differences in depression is proposed. According to this explanation, men are more likely to engage in distracting behaviors that dampen their mood when depressed, but women are more likely to amplify their moods by ruminating about their depressed states and the possible causes of these states. Regardless of the initial source of a depressive episode (i.e., biological or psychological) men's more active responses to their negative moods may be more adaptive on average than women's less active, more ruminative responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The symptom perception hypothesis revised: Depression and anxiety play different roles in concurrent and retrospective physical symptom reporting.

According to the classic symptom perception hypothesis (Costa & McCrae, 1987; Watson & Pennebaker, 1989), the global predisposition to frequently experience a variety of negative emotions—that is, neuroticism (N) or trait negative affectivity (NA)—is associated with inflated physical symptom reporting. We tested a revision of this hypothesis, which posits distinctive roles for depression and anxiety in the physical symptom experience. Three studies tested predictions from the revised symptom perception hypothesis: (a) that depressive affect should be related to inflated retrospective physical symptom reports and (b) that anxious affect should be related to inflated concurrent, or momentary, physical symptom reports. Study 1 assessed the relations among N/NA, depressive affect, and recall of physical symptoms experienced in the previous 3 weeks. Depressive affect was uniquely and positively associated with recalling more symptoms. When entered with depressive affect in multiple regression analyses, neuroticism was not associated with level of symptoms recalled. In Study 2, participants were randomly assigned to anxious, depressed, angry, happy, or neutral mood inductions and then reported about concurrent symptom experience. Participants in the anxious mood condition reported significantly more concurrent physical symptoms than did those in the other 4 conditions. In Study 3, anxious, depressed, or neutral mood was induced, followed by assessment of both concurrent and retrospective physical symptoms. Those assigned to the anxious mood induction reported more concurrent symptoms, while those in the depressed mood condition reported having experienced more symptoms in the past. These findings are consistent with the idea that encoding and retrieval processes, which are differentially associated with anxious versus depressed affect, influence different aspects of physical symptom reporting. The results have implications for self-diagnosis, medical treatment-seeking, and care, and potential insights about other complex social and interpersonal behaviors are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in cue perception in a visual scene: Investigation of cue type.

Sex differences in spatial navigation indicate that women may focus on positional, landmark cues whereas men favor Euclidean, directional cues. Some studies have investigated sex differences in proximal and distal cue use; however, sex differences in gradient (i.e., graded features) and pinpoint (i.e., single, defined) cue perception remain unexamined. In the current experiments, paired photographs were presented in which the 2nd photograph showed the same scene with cues removed (Experiment 1) or isolated (Experiment 2) from the 1st photograph. In Experiment 1, women showed less disruption of task performance than men showed following cue removal but were slowest after proximal pinpoint cue removal. Male performance was slowed by distal gradient and proximal pinpoint cue removal. In Experiment 2, women were faster than men at identifying isolated proximal and distal pinpoint cues and were more accurate at identifying isolated distal gradient and distal pinpoint cues. Better pinpoint cue perception and memory in women indicates one possible mechanism underlying female preference for landmark-based navigation strategies. Findings also show that whereas men may preferentially rely on distal gradient cues they are not better at perceiving those cues than are women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in social behavior: comparing social role theory and evolutionary psychology

In rats, copper deficiency leads to low copper metalloenzyme activity, high serum cholesterol, and cardiovascular lesions. In humans, moderately low copper intake may be common, but the consequences remain largely uncertain. The present study examined the effects of copper supplementation (2 mg/d for 4 weeks in a copper/placebo crossover design) in 20 adult men with moderately high plasma cholesterol. End-point measurements were three copper enzyme activities, erythrocyte superoxide dismutase (SOD), plasma ceruloplasmin (Cp), and plasma diamine oxidase (DAO), and three parameters related to the risk of cardiovascular disease (CVD), plasma cholesterol, plasma lipoprotein (a) [Lp(a)], and lag times for very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) oxidation in vitro. Although copper had no significant effects on any parameter for the entire study group, it did significantly increase two enzyme activities (SOD and DAO), as well as lipoprotein oxidation lag times, in 10 subjects in the lower half of a median split for precopper values. Thus, copper supplementation appeared to influence some types of measurements in subjects beginning with less than median values.     

Sex typing and androgyny in dyadic interaction: Individual differences in responsiveness to physical attractiveness.

In an expansion of the "behavioral confirmation" paradigm developed by M. Snyder et al (see record 1979-26014-001), 12 sex-typed and 12 androgynous (Bem Sex-Role Inventory) undergraduates of each sex engaged in getting-acquainted telephone conversations with allegedly attractive and unattractive members of their own and the opposite sex. Although females were more socially responsive than males, the sexes neither differed in their responsiveness to physical attractiveness nor in their responsiveness to cross-sex and same-sex interaction. As hypothesized, sex-typed individuals were rated by blind judges as being significantly more responsive toward allegedly attractive than unattractive partners. In contrast, androgynous men did not differentiate on the basis of physical attractiveness, and androgynous women actually led allegedly unattractive targets to be rated as more socially attractive than allegedly attractive targets, thereby disconfirming the physical attractiveness stereotype. Because cultural definitions of physical attractiveness are different for men and women, results are discussed in the context of recent evidence that sex-typed individuals have a particular readiness to encode and organize information in terms of gender. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in the longitudinal relations among family risk factors and childhood externalizing symptoms.

Despite potential sex differences in base rates, predictors, and maintaining processes for children's externalizing behaviors, little prospective research has examined sex differences in the relations between concurrent, proximal family risk factors and children's externalizing behaviors. The current study examined the relations among maternal depressive symptoms, maternal parenting behaviors (i.e., negativity and low warmth), and child externalizing symptoms at 24 months and first grade in a community-based sample of 1,364 children enrolled in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. Structural equation modeling revealed that maternal depression and negative parental behaviors were associated with concurrent externalizing behaviors, though maternal depression may be differentially linked to boys' and girls' externalizing problems. The relation between depression and boys' externalizing symptoms was more pronounced at 24 months, and over time, the relation between maternal depression and boys' externalizing symptoms decreased in magnitude, whereas this relation increased among girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Laterality differences in perception: A review.

Defines laterality differences (LDs) as differences in accuracy of recall of recognition, favoring information in 1 visual hemifield over that in another. In research analyzing these differences, stimulus and experimental characteristics have been manipulated to better understand processes affecting LD, and a general functional interpretation in terms of a "postexposural trace-scanning" mechanism has been advanced. Certain structural factors handedness, ocular dominance, and cerebral dominance have been related to LD. Implications of this research and of the postulated explanations are discussed. (78 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion perception explains age-related differences in the perception of social gaffes.

Young (59) adults viewed videos in which the same individual committed a faux pas, or acted appropriately, toward his coworkers. Older participants did not discriminate appropriate and inappropriate behaviors as well as young participants. Older participants also scored lower than young participants on an extensive battery of emotion recognition tests, and emotion performance fully mediated age differences in faux pas discrimination. The results provide further evidence for the role of emotion perception in a range of important social deficits. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Sex differences in self-disclosure: A meta-analysis.

Conducted a meta-analysis of 205 studies involving 23,702 Ss to determine whether there are sex differences in self-disclosure. Across these studies, women disclosed slightly more than men (d?=?18). This effect size was not homogeneous across studies. Several moderator variables were found. Sex of target and the interaction effect of relationship to target and measure of self-disclosure moderated the effect of sex on self-disclosure. Sex differences in self-disclosure were significantly greater to female and same-sex partners than to opposite-sex or male partners. When the target had a relationship with the discloser (i.e., friend, parent, or spouse), women disclosed more than men regardless of whether self-disclosure was measured by self-report or observation. When the target was a stranger, men reported that they disclosed similarly to women; however, studies using observational measures of self-disclosure found that women disclosed more than men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in impulsivity: A meta-analysis.

Men are overrepresented in socially problematic behaviors, such as aggression and criminal behavior, which have been linked to impulsivity. Our review of impulsivity is organized around the tripartite theoretical distinction between reward hypersensitivity, punishment hyposensitivity, and inadequate effortful control. Drawing on evolutionary, criminological, developmental, and personality theories, we predicted that sex differences would be most pronounced in risky activities with men demonstrating greater sensation seeking, greater reward sensitivity, and lower punishment sensitivity. We predicted a small female advantage in effortful control. We analyzed 741 effect sizes from 277 studies, including psychometric and behavioral measures. Women were consistently more punishment sensitive (d = ?0.33), but men did not show greater reward sensitivity (d = 0.01). Men showed significantly higher sensation seeking on questionnaire measures (d = 0.41) and on a behavioral risk-taking task (d = 0.36). Questionnaire measures of deficits in effortful control showed a very modest effect size in the male direction (d = 0.08). Sex differences were not found on delay discounting or executive function tasks. The results indicate a stronger sex difference in motivational rather than effortful or executive forms of behavior control. Specifically, they support evolutionary and biological theories of risk taking predicated on sex differences in punishment sensitivity. A clearer understanding of sex differences in impulsivity depends upon recognizing important distinctions between sensation seeking and impulsivity, between executive and effortful forms of control, and between impulsivity as a deficit and as a trait. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in influenceability.

Examines the hypothesis that women are more influenceable than men in a variety of situations. For persuasion research and for conformity studies not involving group pressure, there is scant empirical support for a sex difference, and for group pressure conformity research, there is support among a substantial minority of studies. Also explored is the possibility that various sex differences in social influence studies are a product of contextual features of experimental settings. This is suggested by the fact that findings reporting greater influenceability among females were more prevalent in studies published prior to 1970 than in those published in the 1970s. Finally, sex differences in various psychological processes that may mediate persuasion and conformity are evaluated as possible explanations for those influenceability sex differences that appear to be genuine. It is suggested that a propensity to yield inherent in the female sex role appears to account for some aspects of influenceability findings, but a 2nd explanation, a tendency for women more than men to be oriented to interpersonal goals in group settings, is also plausible. (7? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in the perception of closure.

This experiment represents an attempt to increase one's general understanding of cognitive functioning in senescence. A comparison is made between the performance of 2 disparate age groups, with mean ages of 26.8 years and 78.1 years, on 2 kinds of perceptual tasks which earlier factorial studies have shown to reflect "the ability to fuse a perceptual field into a single percept" and "flexibility of closure." One group consisted of 16 Ss made up of doctors and nurses, and the other consisted of 16 residents in a home for the aged. They were roughly equated for intelligence. The 2 procedures were a Gestalt Completion Test, adapted by Thurstone from a technique devised by Street, and a Concealed Figures test, adapted by Thurstone from the Gottschaldt Figures Test. The older Ss were distinctly inferior on both tasks. "The over-all results were viewed as reflecting the overly loose or overly rigid cognitive functioning of the aged." 22 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in persistent fatigue

This study examines factors differentiating women and men who suffer from fatigue. It is based on diaries kept by Dutch citizens over a 21-day period between 1987-88. The majority of those with persistent fatigue complaints (PFs) were male, middle-aged, lower-educated and unemployed, and they had more psychological and psycho-social problems than the incidental fatigue sufferers (IFs). Factors differentiating the PFs from the IFs are not the same for both sexes. Moreover, on a number of socio-demographic variables PF men and women differed less from each other than IF men and women. Future research should focus on the gender-specificity of the factors that lead to the development of persistent fatigue.     

Sex differences in occupational performance

Nineteen patients with cystic fibrosis were seen in the I Department of Tuberculosis and Lung Diseases during 3.5 years. There were 12 (63%) female, and 7 male, aged from 16 to 35 years (mean 23.2). Most patients were diagnosed in childhood, but 4 were diagnosed in their early adulthood. The diagnosis was confirmed by positive chloride sweat test in all cases. Molecular DNA analyses were performed in 16 cases. In 9 (56%) cases two mutations in the CFTR gene were identified. In 5 cases one mutation was identified. All patients had bronchiectases confirmed by CT. Spirometry showed lung function impairment with predominantly obstructive pattern. Mean VC was 2.57l, mean FEVI was 1.66l. In 7 (37%) cases FEVI was lower then 30% of predictive value. Hypoxemia was found in 11 (58%) cases and hypercapnia in 3 (16%) cases. Sputum cultures were positive for mucoid P. aeruginosa in 12 (63%) cases, for Staph. aureus in 16 (84%) cases. Persistent colonisation with nontuberculous mycobacteria was found in 2 (10.5%) cases. Aspergillus fumigatus was identified in sputum cultures in 2 subjects who had also positive precipitation test. Diabetes mellitus was diagnosed in 2 cases. Meconium ileus equivalent was seen in 1 case. Pneumothorax was seen in 1 case. One patient died in the endstage of the illness.     

Sex differences in the nervous system of reptiles

1. The study of sex differences in the brain and behavior of reptiles presents an excellent opportunity both to discern general principles of sexual differentiation in the nervous system and to explore the evolutionary history of this process in amniote vertebrates. 2. Findings in several reptiles suggest that some sex differences found in mammals and birds are conserved while others are not. Conserved features include areas in the limbic forebrain involved in the regulation of social and sexual behaviors. As in mammals and birds, it is rare to find differences in the distribution of sex steroid concentrating neurons in reptiles but common to find differences in the distribution of the various steroid hormone receptors and in their regulation. 3. This research has revealed that differences in social and sexual behavior are reflected better by the activity, not by the size, of hormone-sensitive limbic areas. 4. Finally, species differences in plasma levels of sex hormones are paralleled by differences in behavioral sensitivity to these hormones as well as by differences in the regulation of genes coding for steroid hormone receptors.     

Sex differences in the recall of affective experiences

Three studies tested hypotheses for sex differences in the recall of life events: differences in (a) affect intensity at encoding, (b) affect intensity at retrieval, (c) rehearsal, (d) detail of encoding, and (e) artifacts such as motivation or verbal ability. In Study 1 (N = 419), women recalled more positive (p < .01) and more negative (p < .05) life events than men. Differences in retrieval mood were not found. Study 2 (N = 55) replicated the recall differences and showed that neither rehearsal nor artifacts were responsible. Sex differences in recalling neutral everyday events also were obtained (p < .05), suggesting that affect intensity was not responsible. In Study 3 (N = 132), affective reactions to events were unrelated to recall, but sex differences in the detail of encoding (p < .001) were related to recall (p < .05). Sex differences in autobiographical memory are reliable and may be due to differences in the detail of encoding.     

Sex differences in the allocation of pay.

Examined the possibility that relative to males, females perceive less of a connection between their work and monetary rewards. In Study 1, 66 females and 60 males (respondents to an advertisement in a student newspaper) determined either their own pay or the pay of another person. Results support the hypothesis in that females paid themselves less than did males and less than other people (males or females) paid females. Results also suggest that Ss were more generous when they paid females. In Study 2, sex differences in self-pay were examined in 80 1st-, 4th-, 7th-, and 10th-grade Ss. Results replicate those of Study 1, in that at every grade level, females paid themselves less than did males. In addition, the extent to which females allocated pay the way their male counterparts did was highly related to the masculinity of their career goals. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in dehydroepiandrosterone-induced hepatocarcinogenesis in the rat

The direct quantification of antibiotics in agar allows one to study the quality of the agar matrix, the kinetics of diffusion and the bacteria-antibiotic interaction. Mueller-Hinton agar (MHA) plates from three manufacturers were tested using HPLC and the disc diffusion test of ceftazidime (CAZ). Notable differences in the chromatographic profiles of MHA plate extracts from OXOID, DID and Becton Dickinson (BD) were shown, with a higher CAZ concentration after 24 h a 6 mm in BD P. aeruginosa inoculated plates (5.1 +/- 1.7 micrograms/ml, n = 6) vs. OXOID and DID (1.6 +/- 0.3 micrograms/ml, n = 12). BD plates gave also a different inhibition zone diameter (26 +/- 0.5 mm, n = 3) with respect to DID and OXOID (29 +/- 0.5 mm, n = 3).