What’s the buzz...
Scientists have now undertaken a new study to gain new insights into how the brain perceives colour and is able to keep a stable perception of an object’s colour as lighting conditions change.
Telephone counselling good for weight loss
Weight-loss programmes delivered over the phone by health coaches and with website and physician support are just as effective as others involving in-person coaching sessions, a new study has claimed. Lawrence J. Appel and his team from the Johns Hopkins University School of Medicine and the Bloomberg School of Public Health recruited 415 obese people with an average body mass index (BMI) of 36.6 and an average weight of 229 pounds.
Although the group was diverse, it predominantly consisted of middle-aged women.
The volunteers were randomly split into three groups – the control group received information about weight loss but did not receive counselling, another group received counselling over the phone with a coach, and a third group was offered in-person and phone counselling.
Those in the control group lost an average of less than two pounds over the course of two years, while those who had telephone sessions or in-person coaching lost a similar amount of weight, an average of 10 pounds over two years.
How the brain perceives colour and images
The process of seeing an object begins when light reflected off that object hits the light-sensitive structures in the eye, and the perception of an object’s lightness depends on the object’s reflectance, as, objects that appear lighter reflect a larger percentage of light as compared to those that appear darker.
Sarah Allred from Camden Allred said that the brain processes perceptual differences between black and white objects even when illumination of the object changes, as, if the brain did not do this, it would fail to distinguish colour shade in different light. She also said that in general white objects reflect about 90 percent of the light that hits them, and black objects reflect about three percent, a ratio of 30-to-1.
“However, if you look at the intensities of light that enter the eye from a typical scene, like a field of lilies, that ratio is much higher, usually somewhere between 10,000-to-1 and a million-to-1,” Allred said. This happens because in addition to having objects with different reflectance, real “scenes” also have different levels of illumination. One example might be a shadowed area under a tree.
“This research is important because we have falsified the ratio hypothesis, which is currently the most widely invoked explanation of how we perceive lightness,” she said.
Frequent gaming may make brain’s pleasure centre larger
A new study has found that teenagers, who play video games frequently, have brains with larger pleasure centres.
Dr Simone Kuhn of Charite University Medicine in Berlin and a large team of European collaborators, looked at 154 Berlin school children who were all aged 14 and also played video games. The children were split into two groups: infrequent video gamers, who played on average about 4 hours per week, and frequent gamers, who played about 21 hours a week on average.
“An important feature of our study is that none of the children were addicted to video games,” said Kuhn.
When the children underwent an MRI scan, the researchers found that a region of the brain called the ‘ventral striatum’ had more grey matter in the frequent video gamers.
“The ventral striatum is usually associated with everything that brings pleasure”, said Kuhn.
Kuhn thinks that playing the video games makes the pleasure centre grow bigger.
