Readers using e-books are less likely to absorb what they have read because of the simple presentation.
For instance, Amazon's Kindle and the Sony Reader display text in such a clear, legible format that this fosters a 'lazy' brain.
The findings go against the conventional wisdom that legibility makes it easier for people to learn and remember information, according to the Daily Mail, citing a study in the journal Cognition.
A study by Princeton University in the US found that a significant number of those tested could recall more information when it was presented in unusual typefaces. The research suggests that introducing 'disfluency,' by making information superficially harder to understand, deepens the process of learning and encourages better retention.
Psychologists said information which has to be actively generated rather than "passively acquired" from simple text is remembered longer and more accurately.
The study raises questions over how much fonts like Times New Roman and Arial, which are used in the majority of academic books, help readers revise for tests.
American author and psychologist Jonah Lehrer had written about the idea of disfluency in his Wired.com blog before the research was published.
Lehrer revealed he found it less easy to remember information he had read using his Kindle e-reader. Although Kindle users can alter the size of text, they cannot change the Caecilia font, which he described as relaxing to read.
It has been argued that e-readers and computers hinder us from absorbing information because their screens and fonts tell our subconscious that the words they convey are not important.
Lehrer said the study showed the whole history of typography had missed the point when it comes to learning.