the underconnected could make it difficult for children to succeed in school and for adults to get ajob. >>> we asked a psychiatrist to come in and tell us if long-term marijuana use has been linked to poor verbal memory. >> there was a study just published yesterday looking at people from young adulthood into their adulthood. one is organizing and planning abilities, and the other one was in processing speed, how quickly yur bra your brain works. what they found is there is no impact on executive functioning or on processing speed for people who are regular marijuana users. now, for people who are habitual marijuana users defined as use -- use ing on a daily basis, after use of 25 years, there was a difficulty of recalling names and numbers. >> this study followed these people from the time they were, what, teenagers until they were older? >> alate teens to mid-20s, yes. >> what percentage wasn't able to remember names and numbers? >> it's really a small number. basically for every 1,800 times or five years, roughly, that somebody smoked over those 25 years, their ability to recall