This article in Time magazine suggests that engaging in challenging mental tasks may be associated with lower rates of mental decline in older adults. The article states that:
In one study, presented last year at the Cognitive Neuroscientist Society's annual meeting, psychologist and neuroscientist Helena Westerberg of the Karolinska Institute in Stockholm compared the cognitive abilities of 45 young adults (average age 25) with those of 55 older adults (average age 65). She found that after five weeks of computerized training on tasks ranging from reproducing a series of light flashes to repeating digits in the opposite order that they were given, the older group was able to reach the same level of working memory, attention and reaction time that the younger group had at the outset. (Notably, the younger group had even greater improvements by the end of the training period.) "The program is always pushing them to do better," says Westerberg, who notes that an advantage of video-game training is that the programs' difficulty level continually adjusts upward to match players' evolving abilities. "They have feedback and can see their scores."
This might suggest that scientists and professors might have less decline in fluid IQ with age. Is there any support for this idea?