A new study says that some aspects of peoples' cognitive skills, like making rapid comparisons, remembering unrelated information and detecting relationships, will peak at about the age of 22 and then begin a slow decline starting around age 27.Timothy Salthouse, a University of Virginia professor of psychology and the study's lead investigator, and a team conducted the study during a seven-year period, working with 2,000 healthy participants between the ages of 18 and 60.Participants were asked to solve various puzzles, remember words and details from stories, and identify patterns in an assortment of letters and symbols.