Gamma flicker elicits positive affect without awareness

High-frequency oscillations emerged as a neural code for both positive affect and fluent attentional processing from evolutionary simulations with artificial neural networks. Visual 50 Hz flicker, which entrains neural oscillations in the gamma band, has been shown to foster attentional switching, but can it also elicit positive affect? A three-faces display (2-female/1-male or 2-male/1-female) was preceded by a 50, 25, or 0 Hz flicker on the position of the odd-one-out (i.e., the target). Participants decided on the gender (Block 1) or on the subjective valence (Block 2) of this neutral target in an approach-avoidance task, which served as an implicit affective measure. Only the detection of 25 Hz flicker, but not of 50 Hz flicker, was above chance (Block 3). Faces primed by invisible 50 Hz flicker were explicitly evaluated more positively than with 25 Hz or 0 Hz. This gamma flicker also facilitated approach reactions, and inhibited avoidance reactions relative to 25 Hz and 0 Hz flicker in Blocks 1 and 2. Attentional switching was, moreover, enhanced by the 50 Hz flicker. According to the Affect–Gamma hypothesis, also in biological neural networks, high-frequency gamma oscillations may code for positive affect.     

I. Frege and the rise of analytic philosophy∗

Since the beginning of the ‘eighties of the present century, a circle of relatively young American sociologists who are followers of Jeffrey Alexander are making energetic and spectacular efforts to supply sociology with a uniform and comprehensive theoretical framework by continuing Talcott Parsons' lifework. The present article is an appreciation of Alexander's achievements in the justification of a general sociological theory (especially a theory of action and social order) while pointing to objections that can be raised against the character of his theory. A scrutiny of Alexander's metatheoretical deliberations and of his interpretations of sociological classics such as Marx, Durkheim, Weber, and Parsons reveals that Alexander's metatheoretical frame is not flexible enough to actually reconstruct the problem situation of the classics. Pointers are given toward a theory of action that is not subject to the antinomy of utilitarianism and normativism, so that it is more adequate and appropriate to the heritage of the sociological classics, both from a theoretical and an interpretative angle.     

How job characteristics relate to need satisfaction and autonomous motivation: implications for work effort

To explore the motivational potential of job design, we linked job demands and job resources, as defined in the job demands–resources model, to the motivational process defined in self‐determination theory. Specifically, we introduced basic need satisfaction and autonomous motivation as consecutive process variables mediating the relationship between job design and work effort. We tested this model by means of structural equation modeling in a sample of 689 employees. The comparison of several competing models provided support for the hypothesized model. We conclude that job demands thwart and job resources promote the fulfillment of 3 psychological needs. High levels of need satisfaction, in turn, are associated with autonomous motivation and, therefore, with high levels of effort.     

Increased forefoot loading is associated with an increased plantar flexion moment

The aim of this study was to identify the cascade of effects leading from alterations in force generation around the ankle joint to increased plantar pressures under the forefoot. Gait analysis including plantar pressure measurement was performed at an individually preferred and a standardized, imposed gait velocity in diabetic subjects with polyneuropathy (n = 94), without polyneuropathy (n = 39) and healthy elderly (n = 19). The plantar flexion moment at 40% of the stance phase was negatively correlated with the displacement rate of center of pressure (r = ?.749, p < .001 at the imposed, and r = ?.693, p < .001 at the preferred gait velocity). Displacement rate of center of pressure was strongly correlated with forefoot loading (r = ?.837, p < .001 at the imposed, and r = ?.731, p < .001 at the preferred gait velocity). People with a relatively high plantar flexion moment at 40% of the stance phase, have a faster forward transfer of center of pressure and consequently higher loading of the forefoot. This indicates that interventions aimed at increasing the control of the roll-off of the foot may contribute to a better plantar pressure distribution.     

Visuo-Spatial Working Memory Span: A Sensitive Measure of Cognitive Deficits in Children With ADHD

Working memory (WM) has been hypothesised to be impaired in attention-deficit/hyperactivity disorder (ADHD). However, there are few studies reported on tests measuring visuo-spatial WM (VSWM) in ADHD. Some of these studies used paradigms including episodic memory, others only used low memory loads. In the present study we used a VSWM test that has not been used previously in ADHD research. The sensitivity of the VSWM test and a choice reaction time (CRT) test was evaluated in a pilot study by comparing them to two commonly used tests in ADHD-research; the Continuous Performance Test (CPT) and a Go/no-go test, in children with and without ADHD. The groups differed significantly in performance on the VSWM test (P<.01) and CRT (P<.05) but not on the CPT (P>.1) or on the Go/no-go test (P>.1). The results from the VSWM and CRT tests were replicated in a larger sample of participants (80 boys; 27 boys with ADHD and 53 controls, mean age 11.4 years). The difference between the groups was significant for both the VSWM test (P<.01) and the CRT test (P<.01). The effect size (ES) of the VSWM test was 1.34. There was a significant age-by-group interaction on the VSWM test, with larger group differences for the older children (P<.01). Our results show that the VSWM test is a sensitive measure of cognitive deficits in ADHD and it supports the hypothesis that deficits in VSWM is a major component of ADHD.     

Predictors of willingness to register as an organ donor among dutch adolescents

Abstract

In order to identify relevant determinants of organ donor registration among Dutch adolescents, a school-based cross-sectional survey was conducted among 145 high school students. Fifty-one percent of respondents indicated they were willing to register as organ donors and 80% reported a positive general attitude towards registration. Various misconceptions about the registration and donation procedure were identified. On average only moderate knowledge levels related to organ donation were found. In order of strongest association, negative outcome expectancies, past behaviour and experience, positive outcome expectancies, and social outcome expectancies proved to be significant predictors of willingness to register as organ donors. Self-efficacy was indirectly associated with willingness via outcome expectancies. Knowledge about organ donation was not significantly associated with willingness. The results suggest that in order to persuade adolescents to register as organ donors, refutational messages will have to be developed to counterargue the prevailing negative outcome expectancies related to organ donation and registration as an organ donor.     

Demographic,health-related and psychosocial predictors of changes in depressive symptoms and anxiety in late middle-aged and older persons with fall-related injuries

Research on anxiety and depression after fall-related injuries to the extremities and its pre-fall determinants is scarce. The present study sought to examine change between pre-fall and post-fall anxiety and depression and its (pre-fall) predictors. Data were obtained from 181 Dutch persons, aged 57 and older, who sustained fall-related injuries between 1993 and 1997. Demographic (e.g. socio-economic status), health-related (e.g. number of chronic conditions), and psychosocial (e.g. social support, neuroticism) factors were determined in 1993 (prior to the fall). Depressive symptoms and anxiety were determined prior to the fall, and two, five and twelve months after the fall. Taking into account pre-fall anxiety and depression, pre-fall neuroticism was the most consistent, independent predictor of adverse changes in anxiety and depression. Other factors, including severity of the fall and age were not related to changes in anxiety and depression. Our prospective findings may be interpreted as support for the importance of personality for mental health outcomes in persons who have sustained fall-related injuries.