Ignoring reward-related stimuli challenging under pressure

Ignoring cues in the environment that signal something rewarding, such as alcohol or fast food, is more difficult when an individual is stressed, tired, or otherwise distracted, according to a new study published in the journal Psychological Science.

Researchers at the University of New South Wales in Kensington, Australia, knew that individuals find it hard to ignore cues that signal a large reward. The study looked at whether people's general inability to ignore reward cues is something we have no control over or whether we do use our executive control processes, a term for all cognitive processes that allow us to pay attention, organize our life, focus, and regulate our emotions, to constantly work against distractions.

In the experiment, participants looked at a screen that contained various shapes, including a colorful circle. They were told they could earn money if they successfully located and looked at the diamond shape, but that if they looked at the colored circle, the distractor, they would not receive the money.

They were also told that the presence of a blue circle meant they'd gain a higher amount of money, if they completed the diamond task, than the presence of an orange circle. The scientists then used eye tracking to measure where on the screen participants were looking.

The study showed that ignoring these cues became harder as soon as participants had to perform a task while also holding other information in their memory, according to Poppy Watson, PhD, lead author of the study.

"We have a set of control resources that are guiding us and helping us suppress these unwanted signals of reward,” said Watson. “But when those resources are taxed, these become more and more difficult to ignore."

In the high-memory load version of the experiment, participants were asked to memorize a sequence of numbers in addition to locating the diamond, meaning they had fewer attention resources available to focus on the diamond task. Under high memory load, participants looked at the colored circle associated with the high reward around 50 percent of the time, even though this was entirely counterproductive, Watson said.

The findings demonstrate that people need full access to cognitive control processes to try and suppress unwanted signals of reward in the environment.

"This is especially relevant for circumstances where people are trying to ignore cues and improve their behavior, consuming less alcohol or fast food," said Watson. "There's this strong known link between where your attention is and what you eventually do, so if you find it hard to focus your attention away from reward cues, it's even harder to act accordingly.”

Watson said this also explains why people might find it harder to focus on dieting or beating an addiction if they are under a lot of stress. She advises people to try and be strategic about exposure to cues.

"If you are under a lot of cognitive pressure, you should really try and avoid situations where you'll be tempted by signals,” Watson said. “You need to be in the right frame of mind to be in a situation where you can stop yourself from getting distracted and going down a path where you don't want to go.”