Just as athletes can increase their physical performance by eating the right foods, students can better their performance by inhaling a shot of oxygen or swallowing some glucose just before a test.
Andrew Scholey, director of the Human Cognitive Neuroscience unit at the University of Northumbria, discovered through tests that mental strength could be improved by giving the brain the right fuel.
The brain is one of the most energetic organs in the body. Though it accounts for only 2% of our body weight, it uses between 20% and 30% of the body's energy. Despite this need for energy, the brain has what can be thought of as a design fault: it stores only a negligible amount of glucose and needs the blood stream to deliver a constant supply.
Dr Scholey gave a group of students around 30g of glucose and asked to perform a "serial seven" test, where they had to continually subtract seven from an arbitrary starting figure. The students who took the glucose could do between two and three more calculations a minute than another group that did not receive the sugar.
Dr Scholey said that a single dose of the herbal extract gingko - which is thought to boost blood flow and increase glucose metabolism - improved the attention of students for up to six hours.
In another test students had a one-minute blast of oxygen immediately before being given a list of words to remember. The students who took the oxygen remembered two or three more words from a list of 15 than those who did not.
Students who took oxygen while playing the Tetris computer game on its most demanding level were also shown to play significantly better. But oxygen had little effect on performance at lower difficulty levels.
"It looks like the types of cognitive function most affected by oxygen and glucose are tasks with a high level of cognitive demand," said Dr Scholey at the British Psychological Society's centenary meeting in Glasgow.
Blood samples taken from people performing a demanding mental task show lower glucose levels and Dr Scholey believes the body delivers oxygen and glucose to the brain when it faces a difficult task.
"Even the most esoteric brain functions obey biological rules. By tweaking fuel availability to the brain, simply by throwing a bit more fuel on to the fire, you can improve cognitive function to some degree," he said.