Neuroscientists discover previously unknown cognitive benefits of reading physical books

A new study published in the journal PLOS ONE provides evidence that reading comic books on physical paper helps the brain absorb and connect story details more easily than reading on a digital tablet. The findings suggest that physical books provide stable spatial and tactile cues that lower the brain’s workload when a reader tries to recall complex plot points later. This research offers fresh insights into how digital reading formats might subtly alter human reading comprehension and memory.

Reading a book involves a complex series of mental tasks. A reader must decode words, interpret pictures, and connect new information to what they already know. To do this efficiently, the human brain builds what scientists call a story schema. A story schema is an internal mental framework that helps a person organize characters, timelines, and spatial relationships as a narrative unfolds.

The physical format of a book might play a hidden role in constructing this mental framework. Scientists suspect that physical paper provides reliable sensory anchors, such as the thickness of the pages on either side of the binding and the fixed location of text on a page. These physical anchors might help the brain map out the narrative in a physical space. When reading on a digital screen, these sensory anchors are largely absent because the screen remains physically identical while the text simply changes.

The authors of the current study wanted to know if the cognitive effects of paper extend to reading visual narratives. They chose Japanese manga, which are comic books with rich visual and narrative structures, to see how different reading mediums affect brain activity.

Kuniyoshi L. Sakai, a professor in the Department of Basic Science at the Graduate School of Arts and Sciences at the University of Tokyo, explains that the study originated from an industry question. “This research project began with an inquiry from COAMIX INC., one of the major publishers of Japanese manga, whether we could investigate any values of paper books scientifically,” Sakai said. “As a neuroscientist working on the human brain, especially on its language function, I decided to compare brain activation between paper and digital reading.”

To conduct the experiment, the researchers had to overcome a technical hurdle related to measuring brain activity. Magnetic resonance imaging scanners use powerful magnets to track blood flow in the brain, which provides a real-time map of neural activity.

“When comparing a paper book and an electronic tablet, we cannot bring the latter device into the scanning room, because the scanner is a huge magnet,” Sakai said. “Then, I had an idea of scanning the brain after one’s reading a book on paper or tablet. This was a long shot, and the right results we obtained surprised us.”

The researchers recruited 25 right-handed university students who were native Japanese speakers. The scientists used a popular manga series where each story is split into two halves. These halves depict the exact same events but from the different perspectives of a couple experiencing conflicting feelings. This unique format allowed the scientists to test how well readers integrate information across different viewpoints.

Participants were randomly assigned to read the first half of a manga story on either a physical paper book or an electronic tablet. This reading took place in a normal room outside of the scanning machinery. The scientists ensured that both the paper book and the tablet were similar in physical size. They also used light meters to match the brightness of the room’s light reflecting off the paper with the backlight shining from the tablet.

After finishing the first half, the participants entered the scanner. While lying inside the machine, participants wore special digital goggles to read the second half of the story. During this reading phase, the participants periodically rated their empathy toward the characters on a four-point scale to ensure they were actively engaged with the plot.

Finally, while still inside the scanner, the participants answered multiple-choice questions about the story they had just finished. The scientists divided these questions into two distinct categories. Set one included questions that could be answered just by remembering the first half of the story. Set two contained more demanding questions that required the reader to combine details from both halves of the narrative.

The behavioral measurements showed that participants answered the questions with similar accuracy regardless of the medium they initially used. However, their response times differed based on their original reading format. When answering the complex questions from set two, participants who read the first half on a tablet took longer to respond than those who read on paper. The scientists noted that tablet readers required more time to mentally piece together the two halves of the story.

The brain scans provided evidence that matched these behavioral differences. When participants read the second half of the story, those who had started the story on paper showed reduced activity in the left lateral premotor cortex and inferior frontal gyrus. These specific left-sided brain regions are deeply involved in language processing and narrative integration. Lower activity in these areas suggests that the brain did not have to work as hard to understand the new information.

Because the paper readers had already built a strong mental foundation during the first half of the story, integrating the second half required less mental effort. In contrast, tablet readers showed much higher activation in these exact same left frontal brain regions. When answering the complex set two questions, tablet readers also showed increased activity in the right frontal regions of the brain. The scientists explain that these right-sided areas act as a supportive neural system when the brain faces difficult mental tasks.

“We found that both left and right hemispheres, which work during reading mostly for proper linguistic functions and supportive roles, respectively, are less engaged when manga contents are well understood through reading on paper, compared with digital reading,” Sakai told PsyPost. “This neuroscientific result is the first to show such an immediate effect of reading on paper, which would eventually change your brain.”

The amount of activity in these right frontal regions directly correlated with how accurately the tablet readers answered the questions. This indicates that tablet readers had to rely on excessive mental integration processes to achieve the same level of accuracy as the paper readers. The scientists also noticed heightened activity in a brain region called the right angular gyrus among the tablet users. This region is associated with processing spatial relationships, suggesting the tablet readers had to work harder to reconstruct the visual layout of the comic book panels in their minds.

As with all research, there are some limitations. The study specifically used visual narratives, and a reader might wonder if plain text novels would produce the exact same brain patterns.

“The same results would be obtained for reading a novel or other conventional texts, because story lines and contextual flow are basically the same among them,” Sakai said. “One important advantage of using manga stories is that manga has visual narratives, which provide rich pictorial information that facilitates the comprehension of scenes.”

Another factor is the physical difference between the devices themselves. The paper books reflected light from the room, while the tablets used a glowing backlight. Flipping a physical page also takes a fraction of a second longer than tapping a digital screen, which might subtly alter the reading rhythm and give the brain an extra moment to process information.

A reader might misinterpret these findings to mean that digital reading prevents learning, but the accuracy rates show that tablet readers still understood the material. They simply required more cognitive effort and time to reach that understanding. The paper format tends to make the reading experience smoother by providing a consistent physical anchor for the memory.

Future research will likely explore these variables in greater detail and expand to other forms of media interaction. “Using a similar method, we are now examining any effects of writing with a pen or a keyboard,” Sakai said. “This would be a natural next step for comparing paper and electronic devices.”

The study, “Manga reading on paper vs. digital devices: Prospective effects on core and supportive integration processes in the brain,” was authored by Keita Umejima, Yuki Sunada, and Kuniyoshi L. Sakai.