In brief

• Taking an email vacation while on the job can boost job productivity and reduce stress, suggests research by scientists at the University of California, Irvine, and the U.S. Army, presented at a meeting of the Association for Computing Machinery in May. In the study, 13 information technology workers agreed to ignore work emails for five days. Researchers found that the co-workers who continued reading emails had more constant elevated heart rates, while the "vacationers" had more natural, variable heart rates. The email vacationers also reported feeling less stress and being better able to do their jobs and stay on task.

• A supportive supervisor can prevent absenteeism among employees with hazardous jobs, according to research led by scientists at Israel's University of Haifa and the Netherlands's Tilburg University. In the study of 508 transportation workers, researchers asked participants about job hazards, their co-workers' views on "justifiable" absences, and their supervisors' supportiveness, assistance and encouragement regarding work-related problems. Peer pressure and relatively safe jobs did little to encourage employees to come into work, but having a supportive supervisor did. (Journal of Applied Psychology, online March 5)

• When helping strangers, atheists are more motivated by compassion than religious people, according to a study by University of California, Berkeley, researchers. In one of the study's three experiments, more than 200 college students reported how compassionate they felt. Then they played "economic trust games" in which they were given money to share — or not — with a stranger. Participants who scored low on the religiosity scale and high on momentary compassion were more inclined to share their winnings with strangers than other study participants. (Social Psychological and Personality Science, online April 26)

• Anxiety increases cancer severity in mice, according to a study led by Stanford University researchers. Scientists exposed hairless mice to ultraviolet rays for 10-minute bouts three times a week for 10 weeks — exposure similar to that of humans who spend too much time in the sun. After several months, all the mice developed skin cancer, but the nervous ones — those with a proclivity for reticence and risk aversion, as determined by previous behavioral tests — had more tumors than the calmer mice and were the only ones to develop invasive forms of cancer. (PLoS ONE, online April 25)

• Depressed mothers are more likely to needlessly wake their babies at night than non-depressed moms, according to researchers at Pennsylvania State University. The researchers collected data over seven days on 45 babies, age 1 month to 2 years, and their parents. At the start of the week, the mothers also completed two surveys: one examining depressive symptoms and the other measuring their worries about their infants when the mothers woke up at night. The researchers found that mothers with the most depressive symptoms were more likely to worry excessively about their infants' starving or feeling abandoned at night and wake them than mothers with fewer symptoms of depression. (Child Development, May/June)

• By the age of 9 months, babies are better at recognizing faces and emotional expressions of people of their own race, finds research by psychologists at the University of Massachusetts, Amherst. The team placed EEG recording sensors on 48 infants' heads to record their brain activity as they viewed happy and sad people of their own race and of an unfamiliar race. Results showed that 5-month-old infants were equally able to distinguish faces from both races, while the 9-month-old infants were better at telling apart two faces within their own race. Infants were also found to shift their processing of face-related emotion information from the front of the brain to the back of the brain. (Developmental Science, May)

• Teens' impulsive behavior has roots in basic brain function, finds research out of the University of Vermont. Researchers used fmri to monitor brain responses in 1,896 14-year-olds as they moved one hand in response to a stream of commands. The researchers found that teens with a history of using alcohol, cigarettes and illegal drugs — though not under the influence during the study — had impulse control problems associated with diminished activity in their brains' orbitofrontal cortex. The researchers say the differences in these brain networks seem to precede drug use. (Nature Neuroscience, online April 29)

• White public school teachers in the New York metropolitan area appear to give more positive feedback to minority students than to white students for equal work, concludes research led by Rutgers University investigators. In the study of 113 white middle school and high school teachers in the New York metropolitan area, participants read and commented on a poorly written student essay. Results showed that the teachers displayed a "positive feedback bias," providing more praise and less criticism when they thought the essay was written by a minority student than by a white student. (Journal of Educational Psychology, online April 30)

• Motivation is rooted in different hemispheres in left- versus right-handed people, suggests a study by psychologists at The New School for Social Research in New York. Researchers used EEG to compare activity in participants' right and left brain hemispheres during rest, and then asked participants to complete a survey measuring their level of motivation. In right-handers, stronger motivation was associated with greater activity in the left hemisphere, but left-handers showed the opposite pattern. Researchers say these findings may have implications for depression and anxiety treatments that use brain stimulation. (PLoS ONE, April)

• College students believe that using steroids to get an edge in sports is less ethical than using prescription stimulants to enhance one's grades, finds a study by researchers at George Washington University. Approximately 1,200 college freshmen answered a questionnaire that presented two scenarios comparing "Bill," a sprinter for his college track team who uses steroids to improve his performance in a championship meet, and "Jeff," a college student who uses a stimulant to help him focus during his midterm exams. Participants rated Bill as more of a cheater than Jeff. This difference increased among the students who reported misusing prescription stimulants themselves, and among those who play sports. (Psychology of Addictive Behaviors, online April 30)

• Male veterans who conform to traditional ideas of masculinity visit their physicians less often and exhibit other negative health behaviors, suggests research conducted at the University of Mississippi. The study found that male veterans who identified more with toughness, aggression and achievement were less likely to seek medical care, exercise and eat right, and had more post-traumatic stress disorder symptoms than those who identified less with stereotypical masculinity. The men who said that "real men" don't think much about emotions were less adept at recognizing and coping with their own, perhaps making them more vulnerable to PTSD. (Psychology of Men & Masculinity, April)

• Exposure to violence puts wear and tear on children's DNA, finds a study out of Duke University. Researchers examined data from the Environmental-Risk Longitudinal Twin Study, which has followed 1,100 British families with twins since their birth in the 1990s. The findings suggest that children who'd been exposed to violence showed prematurely aged DNA, as measured by the length of the children's telomeres — the region of repetitive DNA at the end of a chromosome that protects the chromosome from deteriorating. Emerging evidence suggests that shorter telomeres are linked to biological age and predict the emergence of chronic diseases. (Molecular Psychiatry, online April 24)

• A simple blood test may be able to help distinguish between people who are depressed and those who are not, finds a study by scientists at Northwestern University. The research used a test involving a panel of 28 biological markers that circulate in the bloodstream and found that 11 of them could predict the presence of depression at accuracy levels that ranged from medium to large. Researchers then further tested the predictive value of these biomarkers with 14 depressed teens and 14 healthy ones. They found that the teens with depression had significantly higher concentrations of the 11 targeted molecules in their blood, including Myristoylated alanine-rich C-kinase substrate (MARCKS) and proto-oncogene c-Maf (MAF). In addition, there were 18 biomarkers that could distinguish between adolescents with depression and those with depression and anxiety. (Translational Psychiatry, online April 17)

• Multitasking may not be so bad for us after all, finds a small study of 63 participants by scientists at the Chinese University of Hong Kong. Participants answered a questionnaire about their media use and then were asked to search for something on a page, both with and without the distraction of an unrelated noise. Participants who reported they frequently used different types of media at the same time performed better at the task when the noise was present than when it was absent. Frequent media users also performed worse than light media multitaskers in the tasks without the noise. (Psychonomic Bulletin & Review, online April 12)

• Playing action-based video games, even for short times, appears to improve visual attention, find University of Toronto psychologists. Twenty-five participants who had not previously played video games played either a first-person shooter video game or a three-dimensional puzzle video game for a total of 10 hours in one- to two-hour sessions. Before and after the participants played the games, scientists recorded the brain waves of participants' who were trying to detect a target among other distractions. The researchers found that those who played the shooter video game improved most on the visual attention task and showed significant changes in brain activity, indicating the brain's increased inhibition of distractors. Those who had played the puzzle game did not exhibit differences in visual attention or brain activity. (Journal of Cognitive Neuroscience, June)

• Head injuries often impair one's ability to make medical decisions, suggests a study out of the University of Alabama at Birmingham. Researchers studied 86 patients with traumatic brain injury, divided into three classifications of severity — mild, complicated mild and moderate/severe — and 40 healthy controls. They found that the more severe the injury, the less able patients were to make decisions about their care. (Neurology, May 8)

• Women who have experienced violence are more likely to later engage in risky sexual behavior, according to a study with 481 low-income women at a publicly funded sexually transmitted disease clinic in Providence, R.I. The women who'd been exposed to multiple forms of violence were later more likely to have unprotected sex, many sexual partners and use alcohol and drugs before sex. (Psychology of Violence, online March 19)

—Amy Novotney