American psychologists have observed that it is in the cortex that our brain detects and blocks distracting stimuli to allow us to stay focused on a task.
- Responses to distracting stimuli are abruptly suppressed beyond the sensory cortex.
- It is the prefrontal cortex that orchestrates this process of filtering stimuli to only pass those that are essential to perform the task at hand.
- This discovery may help to better target and understand the treatment of neuropsychiatric diseases such as attention deficit hyperactivity disorder and schizophrenia.
To stay focused, our brain has the ability to block out many distracting stimuli. Psychologists from the University of California (USA) have for the first time discovered that it is in our cortex that our brain filters stimuli to sort out those that are important for us to perform the task at hand. accomplish and those who are there to distract us. The researchers published their results in the Journal of Neuroscience.
The prefrontal cortex
By conducting experiments on mice, researchers have managed to locate the exact place in the brain where distracting stimuli are blocked. For this, they trained mice in a sensory detection task using target and distractor stimuli. The mice learned to respond to fast stimuli and to ignore identical stimuli in the opposite distraction field. The team used a new imaging technique, which allows high spatiotemporal resolution with a cortex-wide field of view, to find where distracting stimuli are stuck.
The results of this study made it possible to identify the cortex as being the place of our brain filtering the various stimuli. “We observed responses to target stimuli in several sensory and motor cortical regionsnotes Edward Zagha, who led the study. In contrast, responses to distraction stimuli were abruptly suppressed beyond the sensory cortex. (…) When someone is highly distracted, their cortex does not sufficiently deploy the intentional cues necessary to prevent the distractor’s stimuli from propagating into working memory or triggering a behavioral response. These processes — the ‘gatekeepers’ of sensory signals — allow only those signals to pass that are relevant to the task being performed. We believe this process is orchestrated by the prefrontal cortex.”
Treat neuropsychiatric diseases
The next step for researchers is to understand, in neural activity, how distracting stimuli are blocked. “The spatial precision of our results gives us confidence that we know where to look in future studies to reveal how distracting stimuli are blocked, allowing us to stay focused on the task at hand. This major challenge is to record neural activity at high spatio-temporal resolution in animals while they perform targeted taskssays the researcher. The second major challenge is to use the right computational methods to analyze this neural activity..”
This discovery opens up treatment prospects for diseases linked to attention disorders. “Our finding may have important implications for the understanding and treatment of neuropsychiatric diseases such as attention deficit hyperactivity disorder and schizophrenia.notes Edward Zagha. By studying the mechanisms underlying the blocking of distracting stimuli, we may be able to unravel the neural circuitry underlying attention and impulse control. The better we understand these circuits, the better we can design rational and targeted treatments to improve impulsivity in these disorders..”
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