Too many visual distractions may affect our ability to concentrate, says a report published in Science (2001;291:1803- 6). Excess visual input fills up working memory, the process in which information is temporarily stored in the brain. The amount of free working memory affects the level of concentration, so as the memory fills up it becomes more difficult to ignore distractions.

"Our findings suggest that, especially in an environment in which visual distraction is likely, it is crucial that mental processing resources are available for excluding potentially interfering information," says Dr Jan de Fockert, one of the report's authors. "When working memory is occupied, our brains cannot filter out distracting visual information."

In the study volunteers were asked to remember a sequence of numbers, while being distracted by celebrity images. The more numbers the volunteers were asked to remember, the more difficult it became to ignore the visual distractions. Functional magnetic resonance imaging was used to measure brain activity while the study's participants performed the attention and memory tasks. Analysis revealed different areas in the frontal cortex, which related to the amount of strain being placed on the working memory. The areas in the brain that are believed to be associated with face image processing showed greater activity under conditions of high working memory, implying that visual distraction was greater the more the working memory was occupied.

Dr de Fockert pointed out that visual distractions and straining the working memory were integral features of everyday life. "For example, when driving a car in busy traffic, a demanding conversation on a mobile phone will reduce the availability of working memory for excluding distracting information, such as billboards along the road. These distractions compete for attention and reduce task performance."

Although it has not been proved that watching Eastenders will prevent you from doing effective anatomy revision, Dr de Fockert advises that you should "try to avoid taxing mental tasks when dealing with visual environments that include distracting objects." He went on to instruct, "Do not engage in deep thought or demanding conversation when driving."