There is a good body of evidence to suggest that meditation can provide considerable emotional and physical benefits to those people who practise it and, in the long-term, it can improve people's intellectual capacity too. A study of 54 people in Australia aimed to see whether meditation could also confer immediate benefits on people's thought processes. People were enrolled in either a short session of meditation or of relaxation then given tests to assess their cognitive functioning. Meditation was not found to be any more effective than relaxation on any of the measures used.
King, Gillian and Coney, Jeffrey - Short term effects of meditation versus relaxation on cognitive functioning The Journal of Transpersonal Psychology 2006, 38(2), 200-215