Positive effects of stress

A new study explains why stress and anxiety may be both a boon as well as a bane for your brain. "That edge sounds good. It sounds adaptive. It sounds like perception is enhanced and that it can keep you safe in the face of danger," said Alexander Shackman, a researcher at the University of Wisconsin-Madison.

However, it makes us more sensitive to our external surroundings as a way of learning where or what a threat may be, but interferes with our ability to do more complex thinking, said co-author Richard Davidson. When participants in the study were faced with a possibility of receiving an electric shock, researchers saw enhanced activity in brain circuits responsible for taking in visual information, but a muted signal in circuitry responsible for evaluating that information. In the absence of the threat, however, the effect is reversed: less power for vigilance, more power for strategic decision-making. Your ability to do more complex tasks is disrupted just as the amount of information you are receiving through your eyes and ears is enhanced, Shackman said. You are having trouble focussing on the information coming in, but your brain is taking in more and more potentially irrelevant information. You can have a viscous feedback loop, a sort of double-whammy effect. ANI