The bulky, modern human brain evolved hundreds of thousands of years ago and, for the most part, has remained largely unchanged. That is, it is innately tuned to analog information—to focus on the hunt at hand or perhaps the forage for wild plants. Yet we now pummel our ancient thinking organ with a daily deluge of digital information that many scientists believe may have enduring and worrisome effects.
A new study published today in Nature supports the concern. The research suggests that “media multitasking”—or engaging with multiple forms of digital or screen-based media simultaneously, whether they are television, texting or Instagram—may impair attention in young adults, worsening their ability to later recall specific situations or experiences.
The authors of the new paper used electroencephalography—a technique that measures brain activity—and eye tracking to assess attention in 80 young adults between the ages of 18 and 26. The study participants were first presented with images of objects on a computer screen and asked to classify the pleasantness or size of each one. After a 10-minute break, the subjects were then shown additional objects and asked whether they were already classified or new. By analyzing these individuals’ brain and eye responses as they were tasked with remembering, the researchers could identify the number of lapses in their attention. These findings were then compared to the results of a questionnaire the participants were asked to fill out that quantified everyday attention, mind wandering and media multitasking.
Higher reported media multitasking correlated with a tendency toward attentional lapses and decreased pupil diameter, a known marker of reduced attention. And attention gaps just prior to remembering were linked with forgetting the earlier images and reduced brain-signal patterns known to be associated with episodic memory—the recall of particular events.
Previous work had shown a connection between media multitasking and poorer episodic memory. The new findings offer clues as to why this might be the case. “We found evidence that one’s ability to sustain attention helps to explain the relationship between heavier media multitasking and worse memory,” says the paper’s lead author Kevin Madore, a postdoctoral fellow in the department of psychology at Stanford University. “Individuals who are heavier media multitaskers may also show worse memory because they have lower sustained attention ability.”
“This is an impressive study,” comments Daphne Bavelier, a professor of psychology at the University of Geneva in Switzerland, who was not involved in the new research. “The work is important as it identifies a source of interindividual variability when one is cued to remember information”—the differences in attention among the study participants. “These findings are novel and tell us something important about the relationship between attention and memory, and their link to everyday behavior …, [something] we did not know before,” adds Harvard University psychologist Daniel L. Schacter, who was also not involved in the study.
Madore points out that the new findings are, for now, correlational. They do not indicate if media multitasking leads to impaired attention or if people with worse attention