Something tells me that these two areas of study, unfortunately, have interrelated results:

From Wired, “The Web Shatters Focus, Rewires Brain” (Nicholas Carr):

Research was painting a fuller, very different picture of the cognitive effects of hypertext. Navigating linked documents, it turned out, entails a lot of mental calisthenics—evaluating hyperlinks, deciding whether to click, adjusting to different formats—that are extraneous to the process of reading. Because it disrupts concentration, such activity weakens comprehension. A 1989 study showed that readers tended just to click around aimlessly when reading something that included hypertext links to other selected pieces of information. A 1990 experiment revealed that some “could not remember what they had and had not read.”

From the New York Times, “The Impact of the Irrelevant on Decision-Making“:

An intriguing example of transparently irrelevant information that affects behavior comes from a 1974 report on an experiment by the psychologists Daniel Kahneman and Amos Tversky. In the experiment, subjects first spun a wheel that supposedly would stop at random on any number between 1 and 100. Then they were asked what percentage of African countries belongs to the United Nations. For one group of subjects, the wheel was rigged to stop on 10; for a second group, on 65. On average, the first group guessed that 25 percent belong to the United Nations, but the second group guessed 45 percent.

In short, even demonstrably false or irrelevant information can influence judgments, which in turn influence decisions. In such cases, Professors Tversky and Kahneman wrote in 1981, “the adoption of a decision frame is an ethically significant act.”

On a sidenote, also from the Wired article, this makes you wonder about print media’s early attempts to do news video:

In a study published in the journal Media Psychology, researchers had more than 100 volunteers watch a presentation about the country of Mali, played through a Web browser. Some watched a text-only version. Others watched a version that incorporated video. Afterward, the subjects were quizzed on the material. Compared to the multimedia viewers, the text-only viewers answered significantly more questions correctly; they also found the presentation to be more interesting, more educational, more understandable, and more enjoyable.