New research has indicated why people struggle to resist cues for things they might like to avoid like fast food and alcohol.
New research has indicated why it can be so hard to resist the lure of a fast-food ad or neon sign.
A UNSW study published in Psychological Science on Thursday shows ignoring "reward cues" becomes harder when someone is stressed, tired or otherwise straining their brain power.
While that in itself isn't surprising, study lead Poppy Watson said the research indicated why.
She said people used their "executive control functions" to ignore reward cues, rather than it being automatic.
"Crucially we found that, in day-to-day life, people are exhibiting control over their attention away from these things, when it's in their best interests to do so," Dr Watson told AAP.
"We've shown that there's definitely a role here for executive control which is really exciting because it means that there might be a way to strengthen that control."
When a person's control resources are taxed, it becomes harder to ignore signs and cues for things they might want to avoid, Dr Watson said.
The study, which involved 70 to 80 students and was done in collaboration with researchers in the Netherlands, involved the use of an eye tracker which measured where participants looked at a screen.
They were told that if they looked at a diamond shape quickly, they would get a financial reward but it would be cancelled if they looked at another signal which indicated its size.
This was done under conditions of high memory load and low memory load.
The researchers now want to look at how control can be strengthened, with the paper saying its findings could have implications for understanding addiction.