Cognitive Daily

Everyone knows the saying "a picture is worth a thousand words." Bound by that axiom, magazines, newspapers, and most of all, TV, bombard us with pictures every day. The latest hot internet properties aren't text-based sites like Google but picture-based sites like Flickr and YouTube. Psychological research backs this up: we do remember pictures more readily than we remember words.

The next question, of course, is "why?" Recent research by Paul W. Foos and Paula Goolkasian is beginning to shed light on the difference between memory for pictures and words. They had previously found that while short-term memory for simple line drawings was superior to memory for printed words, the advantage disappeared when the word was spoken. This suggests that perhaps the difference between pictures and words in memory isn't as different as we might think.

In a new study, they set out to explore these differences more systematically. Volunteer participants were asked to complete two tasks simultaneously: they had to answer a question about a visual problem while committing a word to memory. This distractor task was designed to make the memory task more difficult, so differences in results could more readily be observed. There were two types of distractors: easy, or difficult. Here are two sample tasks:

One second after the task was displayed on a computer screen, the word they were required to remember was presented. After viewers saw six problems together with the corresponding words -- either pictures, spoken, or printed -- they were asked to recall as many of the words as possible. The experiment was repeated until the list of 54 words (simple nouns like "baby," "whale," and "handcuffs") had each been used in picture, spoken, and print form. Here are the results:

As expected, pictures and spoken words were recalled more accurately than printed words, and the more difficult distractor task impaired memory in every case. Pictures were correctly recalled about 1.5 times as often as printed words. Thus, technically, a picture may in fact only be worth about 1.5 words.

But what about the printed words makes them more difficult to remember? Foos and Goolkasian suspected that printed words are processed too rapidly, and so don't attract the viewer's attention as readily as spoken words or pictures. To address this issue, in a new experiment they asked participants to say the word out loud after it was presented. This time, the results were different:

For printed words, accuracy improved significantly compared to the the first experiment. While spoken words and pictures were still recalled at a slightly better rate, the difference had shrunk considerably. Perhaps all that is needed to improve recall for printed words is to force viewers to pay more attention to them. In a final experiment, that's precisely what Foos and Goolkasian did. Each word to be recalled was "degraded" by either adding visual distractors to the image like this:

Or, in the case of spoken words, adding a background tone to the sound recording. Again the experiment was repeated, but instead of using easy and difficult distractor tasks, the difficult task was always used. Half the time, participants had to remember degraded images and sounds, and half the time, they recalled normal images and sounds, as before. Here are the results:

As expected, fewer printed words were recalled when the words were presented normally. But when the words were degraded, the advantage of pictures and spoken words disappeared: the printed words were recalled as easily as pictures or sounds. What's more, memory for printed words actually improved when the text was degraded, while memory for pictures and sounds worsened.

Foos and Goolkasian argue that the same mental process underlies short term memory for pictures, sounds, and printed words. The difference, it appears, lies in how we process the words when they are presented differently.

More practically, if you need to remember a word, saying it out loud will probably improve your memory. If you're presenting words you want others to remember, pictures or spoken words are still probably your best bet -- just not 1,000 times better.

Foos, P.W., & Goolkasian, P. (2005). Presentation formats in working memory: The role of attention. Memory & Cognition, 33(3), 499-513.