Selective spatial attention—the ability to focus on what matters and ignore distractions—may be controlled by an ancient brainstem circuit, not just the prefrontal cortex. A new study from Johns Hopkins University, published in Nature Communications on June 22, 2026, identifies a specific group of inhibitory neurons in the brainstem that acts as a fundamental “attentional selection engine,” conserved across all vertebrates, including fish, birds, reptiles, and humans.
The Research
Led by postdoctoral fellow Ninad Kothari and senior author Shreesh Mysore, the team trained mice to perform a human-like visual attention task. The mice had to focus on visual stimuli presented directly ahead while ignoring distracting lights to the side. When the researchers silenced the specific brainstem inhibitory neurons using optogenetics, the mice became hyper-distractible—unable to ignore even faint peripheral stimuli. Remarkably, reactivating the neurons the next day completely restored their ability to ignore strong distractors. Rigorous controls confirmed the deficit was purely attentional, not due to vision or motor impairment.
This discovery challenges the long-held belief that attention relies solely on the prefrontal cortex, a region highly developed only in primates. “If we really go back in evolution, for hundreds of millions of years, birds have had this ability, fish have had this ability. And they do not typically have a highly developed prefrontal cortex,” explained Kothari. The brainstem circuit predates the prefrontal cortex by hundreds of millions of years, explaining primitive vertebrates’ spatial focus.
Why It Matters
Because this ancestral architecture is conserved in humans, the findings open new pathways for understanding and potentially treating attention disorders like ADHD and autism. The researchers note that silencing the brainstem circuit induced symptoms mirroring a hallmark trait of ADHD—hyper-distractibility. This suggests that functional deficits in this brainstem engine may underlie such conditions, paving the way for targeted, non-stimulant pharmacological treatments. “A hallmark of ADHD is that even faint distractors draw attention away—and that’s exactly what we see here when these neurons are silenced,” said Mysore.
What You Can Do
While you cannot directly control brainstem neurons, understanding that attention has ancient roots can inform daily strategies. Practice mindfulness to train your brain’s filtering system: focus on one task at a time in a quiet environment, gradually adding distractions. Research shows that attention training improves cognitive flexibility. Also, ensure adequate sleep—fatigue impairs the brainstem’s inhibitory circuits, making you more distractible.
Source: Neuroscience News
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