Televised public service announcements (PSAs) with frequent cuts, bright colors, loud music, and surprising visual images may grab the eye and ear, but are they more likely than other ads to spur viewers to act on their messages? A NIDA-funded study that recorded smokers' brain function while they watched antismoking PSAs suggests that calmer ads may be more effective. Although the researchers did not track whether any smokers quit, they found that low-key ads connected better with some brain regions that would be likely to support efforts to abstain.
This is Your Brain on Ads
Many creators of PSAs suppose that seizing and holding viewers' attention are prerequisites for driving messages home and that highly affective and sensationalistic ads do this best. Recently, however, some theorists have suggested that although viewers cannot take their eyes away from such ads, their ability to absorb and utilize the messages the ads promote may be limited. According to this theory, which has some support in behavioral studies, the brain has only so much capacity to process incoming impressions, so that the more it expends upon the sensational aspects of an ad, the less it has available to process the ad's meaning.
Dr. Daniel Langleben and colleagues at the University of Pennsylvania, collaborating with media expert Dr. Joseph N. Cappella of Penn's Annenberg School for Communication, brought brain imaging to bear on the issue. Their study is the first to monitor individuals' brain responses as they watched antismoking ads in their entirety. "A PSA delivers a coherent message as well as a visual presentation, and scientists need to determine how the brain responds to an ad as a whole," says Dr. Langleben.
The researchers showed 18 smokers, aged 18 to 48, a series of 30-second video clips. From 99 antismoking ads produced before 2002, eight clips were drawn: the four that had been rated "highest sensation" and the four that had been rated "lowest sensation." The sensation ratings had been made using a standard procedure that took into account visual and audio elements and emotional impact. The clips were shown in random order along with eight clips from a wildlife documentary. While participants watched the videos, they underwent functional magnetic resonance imaging.
Both types of PSAs generated more overall brain activity than the wildlife clips, presumably because their content was more relevant to the audience. High-sensation PSAs stimulated activity primarily in the occipital cortex, an area at the back of the brain that processes visual information. The low-sensation PSAs, in contrast, had the largest impact on the prefrontal and temporal cortices, regions associated with attention, memory, and speech processing.
Beginning 5 minutes after the last video clip ended, the participants viewed 128 still frames in random order; 64 were from the PSAs and wildlife clips shown previously, and 64 were from other antismoking and nature videos. After a 3-second presentation of each frame, the participants reported whether they had just seen an ad with this image. They recognized 88 percent of the frames from the low-sensation PSAs as compared with 78 percent of the high-sensation ones. They also were quicker to recognize frames from the low-key PSAs.
Stronger activation in the attention and memory areas of the brain corresponded with greater accuracy on the recognition test, whereas stronger activation in the visual-processing area was associated with lower scores on this test. The results suggest that the frequent cuts, bright colors, and other high-sensation effects may impede PSAs from lodging in memory.
Dr. Langleben cautions that, in contrast to seeing PSAs outside an experimental setting, his study participants' attention to the ads was guaranteed. He also notes that ads did not vary in strength of argument—how convincingly the case for quitting was made—as evaluated by participants in a separate study. Nevertheless, he affirms, "Our findings cast doubt on the premise that flashier ads are always more effective."
Study Tests Opposite Types of Ads
Televised public service announcements (PSAs) can promote important public health messages, including smoking cessation and drug abuse prevention. But what is the best way to convey those messages—with an eye-catching, flashy presentation or a low-key, didactic ad? Dr. Daniel Langleben and colleagues examined brain responses to both types of ads:
A New Tool
Noting that the PSAs shown in the study represented the top and bottom 25 percent of the ads' sensation values, Dr. Langleben adds, "A key goal for future neuroimaging research will be to determine the optimal balance of attention-attracting and message-conveying elements for PSAs." The researchers would also like to examine how initial brain processing of PSAs influences long-term memory for the ads.
"These findings give scientists a basis for examining brain responses to PSAs among important target audiences for these ads—children and adolescents, for example," says Dr. Steven Grant of NIDA's Division of Clinical Neuroscience and Behavioral Research. He notes that high-sensation ads may generate different brain responses—and therefore better attention and memory—among particular groups of people.
One goal of a follow-up study by Dr. Langleben's team is to determine whether participants who are strongly drawn to sensory experiences process PSAs differently than those without this disposition. The team will also examine the interplay between an ad's strength of argument and its graphic attractiveness.
With further testing, health promotion experts may add neuroimaging to their toolbox for PSA development. Dr. Grant says, "Media experts have been arguing about the elements of effective ads for years. This study shows that researchers can use neuroimaging to test competing hypotheses, models, and theories in health communication and marketing."
Langleben, D.D., et al. Reduced prefrontal and temporal processing and recall of high "sensation value" ads. NeuroImage 46(1):219-225, 2009. [Full Text (PDF, 1.6MB)]