Connecting the dots between distraction and neurodegenerative diseases

The older we get, the more distracted we can get—but can we reverse this natural inclination or at least slow it down? This is the aim of two researchers from the CERVO Research Center at Laval University (UL) who are looking at our propensity for distraction in order to determine which attention mechanisms are affected by aging and which neural networks are involved in this phenomenon. Their ultimate objectives are to find a way to counter these changes, but also to establish a clinical tool to detect neurodegenerative diseases as early as possible. Read: Alzheimer's disease: Shank3a protein deficiency may contribute to cognitive decline “Attention disorders are the result of complex cognitive manifestations and processes that remain poorly understood in children and adults. However, we know that aging is an aggravating factor. We also know that attentional difficulties are prodromes of Parkinson's disease and Alzheimer's,” says psychologist and neuropsychologist Roxane Hoyer, a postdoctoral fellow at CERVO. In collaboration with Aurélie Bidet-Caulet, a French researcher from the Institute of Systems Neuroscience in Marseille, Hoyer developed a test which made it possible to define what age the determinants of the propensity for distraction first appear; in other words, the time when the wear and tear on our brain begins to encourage distraction. “Distractibility is the result of a confrontation between three distinct neural networks,” says Hoyer. There is that of voluntary attention, “that which we give to the task to be accomplished, which generates concentration,” opposed to that of involuntary attention, “that which we grant in spite of ourselves to elements which distract us.” Finally, there is the so-called phasic alert network which catalyzes our impulsivity. “It has a latent surveillance function. It keeps the cortex alert and makes it more or less reactive when external signals manifest,” he says. Read: Aging with a healthy brain: How lifestyle changes could help prevent up to 40% of dementia cases The behavioral test developed by the two researchers measures each of these three components. It consists of making people concentrating on visual and sound stimuli react by randomly introducing a distractor element, such as an alarm bell. Hoyer and Bidet-Caulet's team used 191 subjects aged 21 to 86, divided into seven age groups, to conduct this test which lasted around 15 minutes. Their results were presented at the 90th Acfas Congress in early May. They show that each of the three components of the propensity for distraction has its own trajectory over time. Voluntary attention decreases from the age of 30 while involuntary attention increases from the age of 26. As for phasic alert, it diminishes after 25 years and increases around 60 years. Therefore, “aging gradually leads people to pay particular attention to irrelevant information,” noted Hoyer. A clinical validation tool The two scientists are now seeking to refine their results to establish “fine standards” by quantifying the propensity for distraction by age group. “We want to define when our brain is functioning normally to be able to determine precisely when it begins to malfunction,” says Hoyer. Deviations from the norm therefore become indicators of a possible neurodegenerative disease. Their test is currently the subject of a validity study. “We hope to soon be able to provide it to clinicians in the form of a pre-diagnostic tool,” says Hoyer. Hoyer is also collaborating with Philippe Albouy, a professor in the School of Psychology at UL, who is also a researcher at CERVO and is particularly interested in transcranial magnetic stimulation (TMS). “By sending magnetic waves to neural networks involved in working memory, we managed to improve this function in young subjects. These effects were manifested during the application of TMS and during the days that followed,” says Albouy. The two researchers now want to test whether TMS could produce the same effects by targeting the neural networks of distraction propensity. “We want to see if it is possible to retrain the brain not to be distracted,” says Hoyer. This article was translated from French and originally ran in our sister publication Profession Santé.

Connecting the dots between distraction and neurodegenerative diseases

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