WEDNESDAY, March 5 (HealthDay News) -- Teens at risk of developing a substance abuse disorder have deficits in frontal brain activation, a U.S. study concludes.

The researchers used functional MRI to study brain activity in 25 participants, ages 12 to 19, as they did an eye movement test. The scientists found a link between increased risk for a substance abuse disorder and shortfalls in executive cognitive function (ECF).

"ECF is basically the control center for governing other cognitive processes," corresponding author Rebecca Landes McNamee, assistant research professor of radiology and bioengineering at the University of Pittsburgh, said in a prepared statement.

"For example, in school, ECF would be engaged in the planning and control process required in answering a question, formulating your response, raising your hand, waiting until you are called upon, and starting your answer. A person with low levels of ECF might blurt out the answer," McNamee said.

"Another example could be interacting with someone on the playground who upsets you. A person with good ECF will think through the actions and consequences of their behavior rather than responding rashly. A person with low levels of ECF may respond with violence."

In this study, the teens did a task that required inhibition of an initial eye movement as well as a voluntary eye realignment to an alternate location. While they did this, fMRI was used to scan activation in different brain regions.

In addition, each adolescent's neurobehavioral disinhibition (ND) -- the ability to control an immediate impulsive response to a given situation -- was assessed, and their drug use/histories were recorded.

"We found that individuals who exhibit a high amount of ND -- that is, do not have a good ability to manage their impulsive responses -- have less brain activity in the frontal cortex, the region of the brain responsible for ECF, during the antisaccade task. In other words, the regions of the brain responsible for these inhibitory processes engaged less energy in individuals with higher ND scores than those with lower ND scores," McNamee said.

One of the key findings of this study, published in the March issue of the journal Alcoholism: Clinical & Experimental Research, is that behaviors and actions are directly related to brain functioning.

"Teachers, caregivers, and other individuals should understand that each adolescent matures at a different rate; they do not always respond like adults, because their brains are not at the same level of functioning as an adult," McNamee said. "Responses and behaviors related to a certain situation are less easy for some adolescents to manage than others."

More information

The Nemours Foundation has more about teens and alcohol and drugs  .

MONDAY, March 3 (HealthDay News) -- Cutting kids' TV and computer time by half reduced the amount of food they ate and helped them lose weight, a new study found.

The finding offers hope to the problem of childhood obesity in the United States, where an estimated 16 percent of children ages 6 to 19 years old are overweight, a 45 percent increase in one decade, according to federal researchers.

"Television viewing is related to consumption of fast food and foods and beverages that are advertised on television," the study authors said in a prepared statement. "Viewing cartoons with embedded food commercials can increase choice of the advertised item in preschoolers, and television commercials may prompt eating."

The findings are published in the March issue of the Archives of Pediatrics & Adolescent Medicine.

For the study, Leonard H. Epstein, a professor in the department of pediatrics and social and preventive medicine at the University at Buffalo, the State University of New York, and his colleagues studied 70 overweight children, aged 4 to 7, who watched TV or played computer games for at least 14 hours a week.

The researchers installed a monitoring device on each television and computer the child used; the device allowed for the reduction of the children's weekly screen time by 10 percent a week until a 50 percent reduction had been reached. Each family member was given a unique code to activate the TV or computer. In addition, the kids received such incentives as money and stickers to spend less time with TVs or computers.

The other overweight children had no restriction on their use of TVs or computers.

Epstein's team found that the children who had no restrictions on their computer or TV use reduced their TV watching or computer-games playing by 5.2 hours a week. But the kids with restricted use cut their TV and computer time by 17.5 hours a week.

And, the children with restricted TV and computer time lost more weight than the other children. However, the researchers found no difference between the two groups in terms of physical activity.

"Using technology to modify television viewing eliminates parental vigilance needed to enforce family rules and reduces the disciplinary action needed if a child exceeds his or her sedentary behavior limits," the authors concluded. "Perhaps most important, the device puts the choice of when to watch television in the child's control, as opposed to a rule such as 'no television time until homework is completed.'"

Dr. David Katz, director of the Yale University School of Medicine Prevention Research Center, said the study, "shows the upside to this ominous mix -- reducing screen time can help prevent childhood obesity by several mechanisms. Less screen time may be even more important to dietary pattern than to physical activity pattern. But by either means, the ends here are encouraging and highlight the importance of this strategy."

More information

For more on childhood obesity, visit the American Academy of Pediatrics  .

FRIDAY, Feb. 29 (HealthDay News) -- Ever wonder why adults tend to go ga-ga when they see a baby?

Scientists report that sophisticated imaging showed that seeing a baby's face lit up a specific region of the adult brain associated with reward circuitry. This "Christmas tree" effect didn't occur when adults looked at another adult face, suggesting there's a neural basis for protective, nurturing feelings triggered by babies.

And the findings could also shed some light on postnatal depression, which affects some 13 percent of new mothers, the study authors said.

Other experts, however, were divided on the clinical implications of the findings.

"It's interesting that clearly a brain area may be related to an instinctive behavior such as looking at a baby's face," said Paul Sanberg, director of the University of South Florida Center for Aging and Brain Repair. "I think [the study authors] are right that this could [be related to] an underlying brain mechanism of postnatal depression, where this part of the brain may be altered and could effect the ability of mothers to respond to infants' cues."

But Dr. Jonathan Friedman, assistant professor of surgery and neuroscience and experimental therapeutics at Texas A&M Health Science Center College of Medicine, was a bit more cautious when discussing the findings' significance.

"It's an interesting finding without question -- it's never been recorded before," said Friedman, who is also director of the Texas Brain and Spine Institute in College Station. "It's not known if it [the new study] will have clinical significance."

In the 19th century, famed naturalist Charles Darwin noticed that something about infants caused adults to respond instinctively and care for them. In his paradigm, this increased the chances that one's own genes would endure.

And Nobel Prize-winning 20th century zoologist Konrad Lorenz suggested that it was facial structure that prompted these nurturing responses in adults.

But the biological or neural basis for this phenomenon has yet to be explained -- until, perhaps, now.

Using an imaging technique called magnetoencephalography, scientists led by researchers at the University of Oxford in England scanned the faces of 12 adults as they looked at images of 13 infant and 13 adult faces. The study participants had never seen the images before. The faces were matched for emotional content, attractiveness and other features.

Brain activity started in the medial orbitofrontal cortex region of the brain within one-seventh of a second after seeing infant faces, but not adult faces. The responses were considered too rapid to be consciously controlled.

This region of the brain has been implicated in reward behavior; it also appears to be involved in visual object recognition. And depression has been linked to another region of the brain -- the subgenual cingulate cortex -- that is connected to the medial orbitofrontal cortex.

The next step, Sanberg said, would be to see how the adult brain reacts to one's own child. "It could be worth taking this further to see if this is involved in imprinting," he said. "Are there different connections when it's your own child? It's of interest from an evolutionary point of view."

The study results were published Feb. 27 in the journal PLoS ONE.

More information

Harvard University has more on magnetoencephalography  .

THURSDAY, Feb. 28 (HealthDay News) -- Researchers have uncovered another damaging consequence of spanking: risky sexual behaviors, or even sexual deviancy, when the child grows up.

"This adds one more harmful side effect to spanking," said Murray Straus, a spanking expert who was expected to present the findings of four studies at the American Psychological Association's Summit on Violence and Abuse in Relationships in Bethesda, Md., on Thursday.

"I think that it's pretty powerful," said Elizabeth Gershoff, an assistant professor at the University of Michigan's School of Social Work. "It's across several studies and across different forms of either risky or deviant sexual behavior."

Straus, who was the author of all four studies, hopes the findings will raise awareness among child development experts.

"My hope is to convince my colleagues that they ought to put this in their textbooks," said Straus, co-director of the Family Research Laboratory at the University of New Hampshire, in Durham. "It's amazing. Something experienced by all American kids gets an average of half a page in child development textbooks, and not a single one comes to the conclusion that parents should never spank."

Even the revered Dr. Spock, who was anti-spanking, never came right out and advised parents outright not to do it, he added. Instead, Spock advised "avoiding it if you can."

A meta-analysis of spanking studies conducted by Gershoff found 93 percent agreement among studies that spanking can lead to such problems as delinquent and anti-social behavior in childhood along with aggression, criminal and anti-social behavior and spousal or child abuse as an adult.

"There's probably nothing else in child development that has 93 percent agreement in results," Straus said.

Five percent of people who have never been spanked hit their partners, versus 25 percent of those who were spanked frequently.

However, some 90 percent of U.S. parents spank toddlers, according to Straus.

The review being presented at the meeting are the first to look at the relationship of spanking to sexual behavior.

They found that spanking and other corporal punishment is associated with an increased probability of verbally and physically coercing a dating partner to have sex; risky sex such as premarital sex without using a condom; and masochistic sex such as spanking during sex.

There is a "dose response" at work here. "The more parents spank, the higher the probability of harmful side effects," Straus noted.

Of course, there's a similar dose response for smokers. But if someone reaches the age of 65 without developing lung cancer, it doesn't mean that smoking isn't harmful. It means the person was one of the lucky ones.

It's the same with spanking, Straus said. "If a person says, 'I was spanked, and I don't have any interest in bondage and discipline sex, that's correct, but it's not because spanking is OK, it's because they're one of the lucky ones."

And spanking a child once may be like picking up that first cigarette. "The trouble is, if you have a 2-year-old, you pretty soon decide you can't avoid it. The recidivism rate for whatever 'crime' you correct a 2-year-old for is about 50 percent in two hours."

"I've been researching corporal punishment for 30 years and, in the course of that time, the evidence has accumulated that it doesn't work any better than non-corporal punishment but has harmful side effects. I have come to the conclusion that parents should never, ever spank because, although it does work, it's no better than non-hitting methods that don't have harmful side effects. If there was an FDA for spanking, they'd say use an alternative that doesn't have harmful side effects."

More information

Visit the Center for Effective Discipline   for other ways to discipline your child.