• by Erik Sass , July 2, 2007

Radio ads have the same emotional impact as TV ads, according to results of a new study of physiological indicators commissioned by the Radio Ad Lab and performed by Gallup & Robinson.

The study, titled "Engagement, Emotions, and the Power of Radio," contradicts the conventional wisdom about the two mediums, which states that advertising with visuals and motion has a more visceral impact than ads using sound alone.

According to the physiological testing, total excitement levels for radio ads were equal to TV ads. Of 16 radio ads, four actually scored higher than the competing TV spots. What's more, radio ads scored lower "negative" emotional responses.

One physiological measure used in the testing is called Continuous Emotional Response Analysis (CERA). It's based on a technique called facial electromyography, which detects electrical activity in the facial muscles -- an instinctive response indicating some kind of stimulus.

Another is skin conductance, which measures changes in the ability of the skin to conduct electrical impulses, also an instinctive response to stimuli. These "pre-cognitive" physiological responses were then combined with verbal face-to-face interviews, which serve to assess individual response to advertising at the cognitive or conscious level.

Both cognitive and pre-cognitive approaches have their deficiencies, leading researchers to rely on a combination of the two.

Skeptics say data gathered through cognitive interactions isn't always reliable, as it presumes the subjects are both honest in their answers and aware of the full nature of their response to a stimulus, which can take place at a subconscious -- and therefore inaccessible -- level.

Conversely, physiological testing may be considered unreliable because it substitutes physical proxies, like nerve activity, for measures of emotional response. Critics of the technique say this equivalence is too vague and open to interpretation. Some also object that it is based on a circular definition of emotions (as things which cause physical responses).