In an interesting article in the Sunday New York Times, author Maria Konnikova, suggests that Sherlock Holmes was one of the early practitioners of mindfulness. "The Power of Concentration." www.nytimes.com. She points out that Holmes frequently was able to solve his cases while sitting in his rooms at 221 B Baker Street, by concentrating on one aspect of the case at a time. Rather than a multitasker, he was the ultimate unitasker.
The article also discusses several studies which have shown that as little as five minutes a day of mindfulness (sitting quietly, observing the breathing and clearing the mind of all thoughts) can have a beneficial effect on both your emotions and your thinking ability. Based on those studies, mindfulness may even have an effect on preventing the decline in mental ability as we age, including, perhaps, helping to prevent Alzheimer's disease.
Bottom line: if it was good enough for Sherlock Holmes, it surely is good enough for all of us. After all, don't we all want to remain mentally sharp as we age?
Please see my November18, 2012 post, "What is Mindfulness?" for a further discussion of how to use mindfulness and its cognitive benefits. You will be glad you did.