Using signal detection theory, Kessler Foundation researchers improved their understanding of the mechanisms of cognitive fatigue in a recent neuroimaging study comparing participants with multiple sclerosis (MS) and controls. The researchers found an association between signal detection theory metrics, subjective “state” fatigue, and brain activation patterns in both groups. The MS group showed greater effects of fatigue as evidenced by their response bias patterns.
These findings were reported in Frontiers in Behavioral Neuroscience on March 16, 2022, in the open access article “Signal Detection Theory as a Novel Tool to Understand Cognitive Fatigue in Individuals with Multiple Sclerosis” (doi: 10.3389 / fbeh. 2022.828566). The authors are Cristina Almeida Flores Román, PhD, John DeLuca, PhD, Bing Yao, PhD, Helen M. Genova, PhD and Glenn Wylie, DPhil, of the Kessler Foundation.
Because subjective feelings of cognitive fatigue do not correlate with objective measures of performance, researchers have attempted to identify an objective measure of behavior that would incubate with the subjective experience of fatigue. Preliminary research at the Kessler Foundation showed that signal detection metrics (perceptual certainty and response bias) correlated with changes in cognitive fatigue, as well as with striatal activation of the basal ganglia; an area of the brain that Kessler researchers had previously identified as sensitive to changes in cognitive fatigue. They continued their research in this study of MS, which is often complicated by symptoms of fatigue, including cognitive fatigue.
The study was conducted at the Rocco Ortenzio Neuroimaging Center of the Kessler Foundation, which is dedicated exclusively to research in rehabilitation. The researchers used a demanding working memory paradigm to induce cognitive fatigue in 50 participants, 30 with MS, and 20 controls. All participants underwent a structural and functional MRI (fMRI) and were assessed using the visual analog fatigue scale (VAS-F) at baseline and after each block of tasks.
We demonstrated that the response bias was related to subjective state fatigue in MS. This reinforces our previous finding of the same relationship in controls and provides additional support for this metric of signal detection theory as an objective measure of cognitive fatigue. “
Dra. Cristina Almeida Flores Román, postdoctoral fellow of the National MS Society at the Kessler Foundation, lead author
Cognitive fatigue is a feature of many neurodegenerative conditions, including MS, according to Dr. Wylie, director of the Ortenzio Center. “Based on this promising line of research, we are laying the groundwork for a new set of tools,” he explained, “that will help us develop effective interventions to address this disabling condition in a wide range of individuals and improving its impact on daily functioning, employment and quality of life. “
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Magazine reference:
Roman, CAF, et al. (2022) Theory of signal detection as a new tool to understand cognitive fatigue in people with multiple sclerosis. Frontiers in behavioral neuroscience. doi.org/10.3389/fnbeh.2022.828566.