A lady wrote somewhere that multitasking did not suit her.She felt that multitasking meant that one has a pen in one hand, a phone in another and a third task in her mind.
My understanding of multitasking is very different.I feel, when a person multitasks, different dimensions of his skills are manifested. no one person has only one dimension to his personality. If you look hard enough, every person has more than one skill. It is only not realised always. By multitasking, you actually strive to bring into play all your talents.
Besides there is a solid scientific base in support of multitasking.
As soon as a human being is born, the brain starts functioning. It only stops with the person's death. So the only way to prevent fatigue that would set in, is to use a different part of the brain. this can be done by changing your activity. If you are doing analytical work, maybe you could switch to creative work, or maybe do something with your hands.
According to Jain scriptures, the brain can completely focus on one concept for 48 minutes. beyond that it deviates a bit, for normal people. In fact, the jain ritual of Samayik is based on this scientific fact.