This fact may explain why, when people are given a long list of choices, they are more likely to make illogical decisions. The study analyzed brain activity while participants were engaged in one, two and three different tasks.

The frontal lobe on the left side of the brain would light up with one task, and the right side followed as the second task began. When a third task was initiated, the frontal lobes couldn't keep up and the accuracy of the tasks declined rapidly (Helen Briggs, "Brain 'Splits to Multi-Task,'" News.BBC.co.uk, April 15, 2010).