Biasing choice with a button press

It is possible to increase how much a person values something simply by presenting it along with an irrelevant sound that cues the person to press a button, reports a paper published online this week in Nature Neuroscience. This suggests that people’s preferences can be changed without directly manipulating the items they are choosing between.

Tom Schonberg and colleagues asked study participants to tell them how much they were willing to pay for each one of a set of snack foods. Then, they were presented with pictures of the different foods on a computer screen. Most items were viewed passively, but a few of the items were always presented along with a tone that indicated that the participant had to quickly press a button. After this phase of the experiment, participants decided between pairs of snack foods that they deemed equally valuable at the beginning of the experiment. Participants chose the tone associated item 60-65% of the time, and in a subsequent task, they were willing to pay more for these items than for the originally equivalent control items. This behavioral change occurred without the addition of any new incentives, extra information, or increased familiarity, and the effect lasted at least two months. A neuroimaging study with different participants revealed an increased preference-related activity in ventromedial prefrontal cortex, a region often associated with representing subjective value in decision-making. The authors replicated the effect on choice in five independent groups, totaling 240 participants.

Schonberg and colleagues believe that these results suggest a way to help modify choices.