Six-month-old babies are severely limited in what they can remember about the objects they see in the world; if you hide several objects from an infant, they will only remember one of those objects with any detail. But a new study, which will be published in an upcoming issue of Psychological Science, a journal of the Association for Psychological Science, finds that when babies “forget” about an object, not all is lost.

Researchers used to think that babies less than two years old did not understand that an object continues to exist when it is not currently in the baby’s view. But in the mid-1980s, new ways of doing experiments with babies found that they do, in fact, know that objects don’t disappear when you’re not looking at them—a concept known as object permanence. But it was still unknown what babies needed to remember about objects in order to remember their existence.

Now Melissa Kibbe, of Johns Hopkins University, and Alan Leslie, of Rutgers University, are working to figure out exactly what it is that babies remember about objects. For the new study, they showed six-month-old babies two objects, a disk and a triangle. Then they hid the objects behind small screens, first one shape, then the other. Earlier research has shown that young babies can remember what was hidden most recently, but have more trouble remembering the first object that was hidden. Once the shapes were hidden, they lifted the screen in front of the first object. Sometimes they showed infants the shape that was hidden there originally, but sometimes it was the other shape, and sometimes the object had vanished completely. [continue reading…]

Adolescents become smarter because they become mentally quicker. That is the conclusion of a new study by a group of psychologists at University of Texas at San Antonio. “Our findings make intuitive sense,” says lead author Thomas Coyle, who conducted the study with David Pillow, Anissa Snyder, and Peter Kochunov. But this is the first time psychologists have been able to confirm this important connection. The study appears in the forthcoming issue of Psychological Science, a journal published by the Association for Psychological Science.

“Our research was based on two well-known findings, Coyle continues. “The first is that performance on intelligence tests increases during adolescence. The second is that processing speed”—the brain taking in and using new stimuli or information—“as measured by tests of mental speed also increases during adolescence.”

To find the relationship between these two phenomena, the UTSA psychologists analyzed the results of 12 diverse intelligence and mental speed tests administered to 6,969 adolescents (ages 13 to 17) in the 1997 National Longitudinal Survey of Youth. Intelligence was measured by performance on cognitive tests of diverse abilities, such as vocabulary knowledge, math facts, and mechanical comprehension. Mental speed showed up in timed tests of computing and coding—matching digits and words and other arithmetic tasks.

In both of these categories, the researchers could see that the older teenagers did better and worked faster than the younger ones. Then, running the data in numerous ways, they discovered that the measured increase of intelligence could be accounted for almost entirely by the increase in mental speed.

This is what they expected to find, says Coyle. After all, “performance on intelligence tests reflects, in part, the speed of acquiring knowledge, learning things, and solving problems.” Those cognitive processes, he says, are related to how fast the brain is working—and all that improves during the teenage years.

The work reinforces earlier theories about the relationship between increasing processing speed in the maturing brain and the cognitive development of children.
Source: Association for Psychological Science

The risk of depression appears to decrease for women with increasing consumption of caffeinated coffee, according to a report in the September 26 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Caffeine is the most frequently used central nervous system stimulant in the world, and approximately 80 percent of consumption is in the form of coffee, according to background information in the article. Previous research, including one prospective study among men, has suggested an association between coffee consumption and depression risk. Because depression is a chronic and recurrent condition that affects twice as many women as men, including approximately one of every five U.S. women during their lifetime, “identification of risk factors for depression among women and the development of new preventive strategies are, therefore, a public health priority,” write the authors. They sought to examine whether, in women, consumption of caffeine or certain caffeinated beverages is associated with the risk of depression. [continue reading…]