Software tools to keep the brain fit are headed to the workplace. The products have been making a splash in the consumer market in recent years as older Americans wrestle with memory loss and other cognitive declines. And now vendors of "brain fitness" software are beginning to see employers as another fertile market, especially given the desire of baby boomers to stay in the workforce for years to come. Posit Science, a San Francisco-based firm, says several employers are testing its software this year. Posit Science's Brain Fitness Program has been shown to improve the memory of people 60 years or older by 10 years or more, and the company's CEO, Jeff Zimman, expects solid results in corporate trials as well. Still, there are questions about whether the programs are interesting enough to hold employees' attention. Brain training software faces other possible challenges in the shape of neurosurgeons and pharmaceutical firms.