For most people, trying to stop thinking unwanted repetitive thoughts is a familiar experience. A cue can often bring up unpleasant memories or ideas repeatedly. In addition to the need to eject unwanted associations from their mind, people have to ensure that these unwanted associations do not keep coming again and again in an endless loop, and do not become increasingly stronger over time.
In the new study, scientists examined how 80 English-speaking adults came up with new associations to common words. All participants viewed words on a screen and had to type an associated word. In one group people were told ahead of time they would not receive monetary bonuses if they repeated associations. Therefore, they set out to suppress the thoughts of words they had previously input.
Based on reaction times and how effective participants were at generating new associations, the researchers used computational approaches to model how people were avoiding repeated associations. Most people, they found, use reactive control – rejecting unwanted associations after they have already come to mind.
“This type of reactive control can be particularly problematic,” the authors say, “because, as our findings suggest, thoughts are self-reinforcing: thinking a thought increases its memory strength and the probability that it will recur. In other words, every time we have to reactively reject an unwanted association, it has the potential to become even stronger. Critically, however, we also found that people can partially preempt this process if they want to ensure that this thought comes to mind as little as possible.”
“Although people could not avoid unwanted thoughts, they could ensure that thinking an unwanted thought does not increase the probability of it coming to mind again,” Fradkin adds. “Whereas the current study focused on neutral associations, future studies should determine whether our findings generalize to negative and personally relevant unwanted thoughts.”
Reference: “If you don’t let it in, you don’t have to get it out: Thought preemption as a method to control unwanted thoughts” by Isaac Fradkin and Eran Eldar, 14 July 2022, PLOS Computational Biology.
Funding: This work has been made possible by NIH (National Institutes of Health) grants R01MH124092 and R01MH125564, ISF (Israel science foundation) grant 1094/20 and US-Israel BSF (binational science foundation) grant 2019801 to EE. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.