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So how do we stop thoughts? What does neuroscience have to say? Scientists studying intrusive thoughts have leaned on inhibitory control, a mechanism that enables us to stop. When you stop yourself from grabbing a hot pot on the stove before your burn yourself, you have inhibitory control to thank.

Inhibitory control research has exploded in the last two decades. For stopping simple actions like key presses and eye movements, we have a sophisticated understanding achieved via imaging, intracranial recording, modeling and invasive work with non-humans. www.sciencedirect.com/science/arti...

This work's mechanistic depth,along with simple methods of quantifying motor stopping ability, like the stop-signal task, have drawn scientists to apply its methods/lessons to understand intrusive thinking in psychiatric disorders, with variable success. www.cambridge.org/core/journal...

Nevertheless, the clear importance of inhibitory control has earned it a seat at the table as a construct relevant to controlling intrusive thoughts, and more broadly, as a fundamental component of executive function. www.nature.com/articles/s41...

But there is one problem. Stopping motor actions does not invoke thought inhibition, and cannot be used to identify its unique properties. Stopping actions must be achieved by affecting motor cortex; stopping thoughts, by affecting cortical areas represent the thought. The pathways must differ.

This is not a small point. Inhibitory control ability does not equate to prefrontal function. Your ability is determined by the entire circuit that implements stopping. Response inhibition measures will include influences of downstream motor circuitry irrelevant to thought stopping.

And response inhibition will NOT be influenced by parts of thought stopping circuitry unique to the latter. It's a little like testing models of audition by using a using a visual task. No matter how precise, elegant, and simple your visual task is, it's at best partially relevant to your goal.

But what do we do instead? Is there another model system for inhibitory control that is conceptually relevant and well understood? YES! RETRIEVAL STOPPING. Retrieval underlies much of the thinking we do. Thoughts do not emerge from nowhere. Perceptual cues or other thoughts elicit them.

Indeed, persistent intrusive thoughts are usually retrieved in response to reminders. If so, stopping unwanted thoughts would involve recruiting inhibitory control to stop their retrieval, given a cue. This conceptualization captures every form of intrusive symptom across psychiatric disorders.

Our article integrates 25 years worth of research on the cognitive and brain mechanisms underlying retrieval stoppping. Retrieval stopping shares prefrontal and striatal components with action stopping, but instead modulates hippocampal and cortical regions that represent thoughts.

To capture this fundamental difference, we introduce the concept of a FRONTO-TEMPORAL INHIBITORY CONTROL PATHWAY to capture what is distinct about mental control. This pathway has unique parameters that dictate thought stopping success that are not captured by response inhibition.

For example, successful thought stopping is strongly influeced by concentrations of GABA in the hippocampus, that enable hippocampal down-regulation to occur, when people suppress retrieval. www.nature.com/articles/s41...

In another example, hippocampal subfield CA1 volume predicts prefrontal suppression of hippocampal activity during intrusions in a retrieval stopping task, and CA1 volume reduction also predicts intrusive symptoms in people with PTSD. www.sciencedirect.com/science/arti...

Critically, we review evidence that retrieval stopping of unwanted thoughts plays an important role in attenuating affective responding to suppressed content, and also that training people to suppress fearful thoughts improves their mental health. www.science.org/doi/10.1126/...

These benefits of thought suppression contradict clinical wisdom about the inadvisability of thought suppression. Yet, they are consistent with the (also popular) notion that inhibitory control is fundamental to coping with perseverative thoughts and with resilience broadly. lir-mainz.de/en/home

We also discuss the idea that affective stopping engages the same domain general prefrontal components as retrieval stopping, providing an account of fear extinction's benefits. @stevemaren.bsky.social en.bsky.social‬ ��� joeydunsmoor.bsky.sococial @thephelpslab.bsky.social

Fundamentally, if neuroscience is going to inform how unwanted thoughts are controlled by the brain and address central features of psychiatric disorders, a theoretically valid construct and set of tools for measuring that construct are needed.

Research on inhibitory control over memory provides a rich neurocognitive framework through which to understand disordered thought control.More broadly, it complements response inhibition as a tool for understanding the control of action and thought.

Addressing intrusive thinking is a vital mission in clinical neuroscience and psychiatry. Several years ago, 40 scientists from around the world gathered in an Ernst Strugman forum on Intrusive thinking, organised by Peter Kalivas and ‪@mpwpaulus.bsky.social‬ and facilitated by Julia Lupp.

The participants produced an important volume on this subject that lays out the mission of addressing intrusive thoughts and its importance, from diverse perspetives. esforum.de/publications...