Diurnal pattern of luminance discrimination in humans

The visual discrimination threshold can be considered as an image of the resolution power of the visual system. Measured with a psychophysical method, it shows a diurnal pattern with a low threshold in the morning, i.e., high sensitivity and an increase in the afternoon that persists until the early evening.     

Parenting Stress and Childhood Psychopathology: An Examination of Specificity to Internalizing and Externalizing Symptoms

The purpose of this study was to examine if specificity exists between three factors of parenting stress (i.e., parental distress, parent–child (PC) dysfunctional interactions, and difficult child) and childhood internalizing and externalizing symptoms. The incremental validity of parenting stress beyond parental psychopathology was also examined. The sample was drawn from families of children aged 5–17 (N = 300), who sought treatment for their child from a community mental health clinic. Results indicated that the PC dysfunctional interactions factor showed specificity to internalizing symptoms when controlling for parental psychopathology. Parental distress did not show specificity or incremental validity and the difficult child factor was associated with both internalizing and externalizing symptoms when controlling for parental psychopathology. The influence of age, gender, and ethnicity on these associations is also presented, and findings are discussed in terms of how the results add to understanding the specific relations between parenting stress and child and adolescent symptoms.     

Selflessness Meets Higher and More Stable Happiness: An Experience Sampling Study of the Joint Dynamics of Selflessness and Happiness

Previous studies have demonstrated the existence of a positive relationship between selflessness and happiness. However, none of these studies yet differentiated the between—and within—person levels of analysis. Moreover, the Selflessness/Selfcenteredness Happiness Model (SSHM) suggests that selflessness might stabilize happiness. In this experience sampling study, we explored the relationships between selflessness and happiness—baseline and stability—at both the within and betweenperson levels. During five consecutive days, participants responded seven times a day to short questions about happiness and selflessness. Our results showed that more selfless individuals were happier and that more selfless moments of an individual were also happier moments. Moreover, more selfless individuals were more stable from one day to the other. Finally, people becoming more selfless experienced more happiness stability at the following assessment moment and the next day. This study brings new evidence of the importance of selflessness for happiness.