NEWS&ANALYSIS

PSYCHOLOGY Searching for the Effect on People’s Memory Four years ago, Betsy Sparrow became exas- perated watching an old black-and-white fi lm called Gaslight. She recognized the young actress playing the maid but couldn’t remem- ber her name. Luckily, she had her . “I found the answer* online immediately,” she says, and the relief was palpable. That incident sparked a conversation with her husband that continued into the night. “How did we use to remember things like this before the Internet?” wondered Sparrow, who at the time was a psychology graduate student at Harvard University. In a study (http://scim.ag/B-Sparrow) reported online this week in Science, the now assistant professor at doesn’t directly answer that question. But in four cleverly designed experiments, Sparrow External brain. There’s a growing belief, illustrated in this xkcd comic, that people have become more and her colleagues do explore how the Inter- dependent on online information, but few studies have directly examined this.

net may be changing the way people handle on July 14, 2011 such information now. The results, she says, chological method called a Stroop task. After any had been altered. In a different version support a growing belief that people are using the trivia questions were posed, various col- of the experiment, subjects were asked to the Internet as a personal memory bank: ored words would appear on the screen. remember where the information had been the so-called Google effect. What surprised When those words matched topics that peo- saved on the computer. Sparrow most was not people’s reliance on ple were already thinking about, they tended In both cases, the students who had been nonmemorized information but their ability to to react more slowly when asked to name the told that their notes would be erased again fi nd it. “We’re remarkably effi cient,” she says. words’ colors. And indeed, when the colored had the most accurate memory of the infor- Sparrow says her movie trivia failure words were Internet-related, such as Google mation. But the most strikingly accurate

reminded her of a concept called transactive or Yahoo, the students answered more slowly, recall was for the location of information on www.sciencemag.org memory, proposed 30 years ago by her Ph.D. indicating that they were already considering the computer. For example, when posed the adviser Daniel Wegner. According to the the- going online for answers. question, “What folder was the statement ory, people divide the labor of remember- Then Sparrow played a trick on her sub- about the ostrich saved in,” students easily ing certain types of shared information. For jects. She presented 40 different trivia state- answered correctly. In short, Sparrow says, example, a husband might rely on his wife to ments to the students and had them type the they were better at remembering where infor- remember signifi cant dates, while she relies factoids on the computer. She told half of the mation was stored than the information itself.

on him to remember the names of distant group in advance that the computer would The study is “convincing,” and “there is no Downloaded from friends and family—and this frees both from save what they had written so they could see it doubt that our strategies are shifting in learn- duplicating the memories in their own brains. later; she told the other half that the computer ing,” says Roddy Roediger, a psychologist at Sparrow wondered if the Internet is fi lling this would erase it. Then all of the students were Washington University in St. Louis, Missouri. role for everyone, representing an enormous challenged to write down the statements from “Why remember something if I know I can collective act of transactive memory. memory. Those who had been told that the look it up again? In some sense, with Google To test this idea, Sparrow devised a series computer would erase their notes had by far and other search engines, we can offl oad some of offline experiments to catch people in the best memory of the statements, as if their of our memory demands onto machines.” But the act of relying on future access to infor- brains had made an emergency backup. Those Roediger says this trend started long before mation—say, a —rather than who were expecting to retrieve the informa- the Internet. “When I was a student, many memorizing the information themselves. tion later performed more poorly. years ago, we consulted books and encyclo- “I didn’t want them to actually have access In a further set of experiments with 62 pedias to write papers. Now students can do to the information but just think that they Columbia students, Sparrow tested whether it at home on computers. Is that a bad thing? I would,” she says. For the fi rst set of experi- that backup memorization comes at a cost. don’t think so.” ments, which involved 106 Harvard under- She again posed trivia questions but allowed Our increasingly information-rich envi- graduates working on desktop computers, the students to type notes. Some were told ronment may, Roediger suggests, even be Sparrow tested whether people thought of after each note that it would be saved in one stimulating minds enough to account for the the Internet as soon as they were posed true- of six computer folders with labels such as mysterious Flynn effect, the gradual increase false questions such as, “An ostrich’s eye is “Facts” or “Items,” while others were told it in IQ scores observed over the past century. bigger than its brain.” She employed a psy- would be erased. Then she showed the stu- Never heard of it? Don’t worry, Roediger *The Gaslight actress? An 18-year-old Angela Lansbury. dents a list of the statements, with several of says: “There is a Wikipedia article about it.”

CREDIT: RANDALL MONROE / XKCD.COM / MONROE RANDALL CREDIT: Did you already look online? them modifi ed, and asked them to identify if –JOHN BOHANNON

www.sciencemag.org SCIENCE VOL 333 15 JULY 2011 277 Published by AAAS