joe hardy, the head of the science team at lumosity, says the idea of being able to improve and train the brain as we get older is relatively new. >> previous to maybe 30 years ago, neuroscientists believed that the brain was effectively fixed in it's ability to process information, pay attention, plan, remember. we now know that the brain is constantly changing the way that it operates in response to the challenges and activities it's engaged in. >> reporter: the concept is called neuroplasticity, meaning the brain continues to adapt, change, and perhaps be trained even as we age. it's the underlying foundation for the many start up companies that are developing brain fitness programs and bringing them to market. but are the claims of these companies supported by the science? >> the claims being made by most of these companies that are selling products to improve your brain are exaggerated. >> reporter: laura carstensen is director of the stanford university center on longevity, an expert and author on the aging brain. >> when marketers tell you that you can increase your i.q. by 20