A review of the H-reflex and M-wave in the human triceps surae

The soleus is the most commonly used muscle for H-reflex studies in humans, while limited comparable data have been produced from the gastrocnemii muscles. This article reviews the fundamental differences between the structure and function of the human soleus and gastrocnemii muscles, including recent data published about their complex innervation zones. Protocols for eliciting, recording, and assessing the H-reflex and M-wave magnitude in the human triceps surae are also discussed.     

Masculinity, Femininity, and the Bem Sex Role Inventory in Turkey

The aim of this study was to examine the masculinity and femininity scales of Bem Sex Role Inventory (BSRI) among Turkish university students. Five hundred thirty-six students (280 men and 256 women) volunteered to complete the short-form of the BSRI and answer demographic questions. In factor analyses, the original factor structure (Bem, 1981) was found both in the mens and womens data. Comparisons of the factor structures with target rotation (Procrustes rotation) and comparison indexes showed no difference between the factor structures found among men and women. The internal consistency of the masculinity and femininity scales was acceptable, and t-tests showed that women scored higher on the femininity scale, and men scored higher on the masculinity scale. There were significant differences between men and women only on two masculinity items, but significant differences were found in 8 (of 10) femininity items.     

Determinants of stress-related growth: Gender,stressfulness of the event,and coping strategies

The present study aimed to investigate the determinants of stress-related growth. For this aim the associations of gender, stressfulness of the event, and three coping strategies (problem-oriented, fatalistic, and helplessness) with stress-related growth were tested by multiple regression analysis. Participants were 132 undergraduate students. Results revealed that females reported higher levels of stress-related growth than males, and as expected, higher levels of the stressfulness of the event associated with more stress-related growth. Furthermore, frequent utilization of problem-oriented and fatalistic coping strategies was associated with higher stress-related growth. These findings were discussed in the light of relevant literature and culture-specific features. This work has been supported by the Turkish Academy of Sciences, in the framework of the Young Scientist Award Program (TG-TUBA-GEB>P/2002-l-l 1).     

Schizophrenia and deliberate self-harm: a systematic review of risk factors

Deliberate self-harm (DSH) is a strong predictor of suicide in schizophrenia. The aim of this review was to identify risk factors for DSH in schizophrenia. This systematic review of the international literature examined cohort and case-control studies of patients with schizophrenia or related diagnoses that reported DSH as an outcome. Studies were identified by searching electronic databases and reference lists, and by consulting international experts. Fourteen studies met the eligibility criteria. Of the 29 variables examined by two or more studies, five (past or recent suicidal ideation, previous DSH, past depressive episode, drug abuse or dependence, and higher mean number of psychiatric admissions) were associated with an increased risk of DSH, and one (unemployment) was associated with a reduced risk. Schizophrenic patients with these risk factors need careful follow-up and monitoring, with treatment of any associated comorbid depression or drug abuse. Large, prospective studies of DSH in schizophrenia are needed to further define risk factors and to build on the findings of this review.     

Personality dimensions across cultures

In order to generalize the dimensional structure of personality-relatively independent groups of covarying traits-across languages and cultures, a large number of cultures must be studied. Until recently only a few worldwide personality datasets have been available. The first large-scale studies indicate that the pattern of covariation between personality traits is universal and is relatively easily generalizable across languages and cultures. In contrast to the structure of personality, the comparison of the mean trait scores across cultures is much more problematic because cross-cultural differences turned out to be very small in their magnitude, about one-third of the magnitude of individual differences within culture. More integral (e.g., the similarity between personality profiles) or subtle (e.g., the disparity between positively and negatively worded items) measures can reveal more systematic relationships with relevant socioeconomic and geographic variables than the mean scores themselves. Relatively modest sizes of cross-cultural differences in the mean values may imply that a reasonable scalar equivalence can be achieved, and all individuals, irrespective of their language and culture, can be represented in a common metric.     

Socially meaningful vocal plasticity in adult Campbell's monkeys (Cercopithecus campbelli)

Campbell's monkeys (Cercopithecus campbelli) frequently exchange vocalizations, the combined-harmonic calls, with individuals responding to one another's calls. Previous work has shown that these calls can be grouped into several structural variants. Adult females differ in their variant repertoires, which may change during their adult life, particularly after changes in the group composition. Playback of females' currently produced variants triggered vocal responses from other group members, whereas the same females' former, no longer used variants and those of stranger females never did. In contrast, former variants caused long-term cessation of vocal behavior, whereas stranger variants had no effect. Data showed that monkeys were able to distinguish between the different types of variants, indicating that these calls form part of a long-term social memory.     

Aging and conditional probability judgments: a global matching approach

Age differences in bias in conditional probability judgments were investigated based on predictions derived from the Minerva-Decision Making model (M. R. P. Dougherty, C. F. Gettys, & E. E. Ogden, 1999), a global matching model of likelihood judgment. In this study, 248 younger and older adults completed frequency judgment and conditional probability judgment tasks. Age differences in the frequency judgment task are interpreted as an age-related deficit in memory encoding. Older adults' stronger biases in the probability judgment task point to age differences in criterion setting. Age-related biases were eliminated when age groups were equated on memory encoding by means of study time manipulation. The authors conclude that older adults' stronger judgment biases are a function of memory impairment.     

No aging bias favoring memory for positive material: evidence from a heterogeneity-homogeneity list paradigm using emotionally toned words

Some authors argue for a memory advantage of older adults for positively toned material. To investigate the contribution of selective processing to a positivity effect, the authors investigated young (n = 72, aged 18 to 31) and older (n = 72, aged 64 to 75) adults' memory for emotionally toned words using a multitrial paradigm that compares performance for heterogeneous (mixed valence) and homogeneous (single valence) lists. Regarding the age comparison, there was no evidence for an aging bias favoring positive material. Moreover, older adults' memory was less affected by emotion-based processing prioritization. Although there was no support for age-specific processing biases in memory for emotionally toned words, the findings are consistent with proposals that negative information receives processing priority in some contexts. Possible limits to the generalizability of the present findings (e.g., to nonverbal material) are discussed.     

Do chickens (Gallus gallus f. domestica) decompose visual figures?

To investigate whether learning to discriminate between visual compound stimuli depends on decomposing them into constituting features, hens were first trained to discriminate four features (red, green, horizontal, vertical) from two dimensions (colour, line orientation). After acquisition, hens were trained with compound stimuli made up from these dimensions in two ways: a separable (line on a coloured background) stimulus and an integral one (coloured line). This compound training included a reversal of reinforcement of only one of the two dimensions (half-reversal). After having achieved the compound stimulus discrimination, a second dimensional training identical to the first was performed. Finally, in the second compound training the other dimension was reversed. Two major results were found: (1) an interaction between the dimension reversed and the type of compound stimulus: in compound training with colour reversal, separable compound stimuli were discriminated worse than integral compounds and vice versa in compound training with line orientation reversed. (2) Performance in the second compound training was worse than in the first one. The first result points to a similar mode of processing for separable and integral compounds, whereas the second result shows that the whole stimulus is psychologically superior to its constituting features. Experiment 2 repeated experiment 1 using line orientation stimuli of reversed line and background brightness. Nevertheless, the results were similar to experiment 1. Results are discussed in the framework of a configural exemplar theory of discrimination that assumes the representation of the whole stimulus situation combined with transfer based on a measure of overall similarity.     

A study of 60- to 89-mo.-old children's skill at writing numerals

The skill of writing numerals necessitates a certain developmental maturity. Studying the age at which children start to develop this skill and assessing problems they encounter while writing numerals should give direction to their training. From 8 schools a total of 267 children, ages 60 to 89 mo., were asked to write the numerals 1 to 9. Analysis showed that 80% of the children wrote most of the numerals correctly, 15% wrote inverted numerals, 2.0% wrote some numerals as letters, and 4% did not write certain numerals at all. In addition, 64% of children ages 60 to 65 mo. gave correct responses, and the perception of correct responses increased across age groups until 95% were correct in the group who were 84 to 89 mo. There was no significant difference between girls and boys in these writing skills.