Variability of Reaction Time as a Marker of Executive Function Impairments in Fibromyalgia

Abstract

In addition to chronic widespread pain and depression and anxiety symptoms, patients with fibromyalgia frequently experience cognitive problems. This study investigated executive functions in fibromyalgia via a Go/No-Go task. To obtain comprehensive information about performance, traditional and ex-Gaussian parameters of reaction time (RT) variability were used, in addition to speed and accuracy indices. Ex-Gaussian parameters show an excellent fit to empirical RT distributions. Fifty-two female fibromyalgia patients and twenty-eight healthy controls participated. The task included 60 visual stimuli, which participants had to respond to (Go stimuli) or withhold the response to (No-Go stimuli). After 30 trials, the task rule changed, such that previous No-Go stimuli had to be responded to. Performance was indexed by the hit rate, false alarm rate, and mean ( M ) and intraindividual standard deviation (SD) of RT and the ex-Gaussian parameters mu, sigma, and tau. Mu and sigma indicate the M and SD of the Gaussian distribution; tau reflects the M and SD of the exponential function. Patients exhibited a lower hit rate, higher M RT, and higher tau than controls. Moreover, patients showed greater decrease of the hit rate after the change of task rule. In the entire sample, SD, sigma, and tau were inversely associated with the hit rate and positively associated with the false alarm rate. While the greater decline in hit rate after the change in task rule indicates deficient cognitive flexibility, the lack of any difference in false alarm rate suggests intact response inhibition. Higher M RT reflects reduced cognitive or motor speed. Increased tau in fibromyalgia indicates greater fluctuations in executive control and more frequent temporary lapses of attention. For the first time, this study demonstrated that indices of RT variability, in particular those derived from the ex-Gaussian function, may complement speed and accuracy parameters in the assessment of executive function impairments in fibromyalgia. Optimized assessment may facilitate the personalization of therapies aimed at improving the cognitive function of those with the disorder.

Biomarkers of attention bias during public speaking anxiety

“…The result suggested that increased σ, which has been found to be related to impairment in the variability of typical RT responses [21] in the emotional condition is related to increased state anxiety in HPSA individuals. The effect is illustrated in the scatterplot in Figure 2 We observed a higher 𝜇 in the HPSA (560.3746, 20.60063 ms) compared to LPSA (536.4821, 20.60063 ms) group, in line with [7]. However, repeated measures ANOVA showed non-significant 𝜇 differences between both the HPSA and LPSA groups [𝐹 (1,22)=1.43780, partial ƞ 2 =0.03, 𝑝=0.243251].…”

“…Previous studies have consistently reported higher ex-Gaussian 𝜇 values in those with multiple sclerosis (MS) [12], while higher σ values have been associated with individuals experiencing anxiety, potentially linked to attention bias [6]. Moreover, elevated τ values have been found in research focusing on subjects with ADHD [6], fibromyalgia [7] and anxiety [6]. These collective findings align with the hypothesis of our study, further supporting the notion that investigating the ex-Gaussian parameters can shed light on attention bias.…”

An Integrative Neuropsychological Approach to Chronic Pain, Emotions, and Clinical Symptoms

“…The majority (three in total; [ 9 – 11 ]) examined fibromyalgia syndrome (FMS), one of the prototypical chronic pain conditions characterized by widespread chronic pain and symptoms, such as fatigue, unrefreshing sleep, cognitive deficits, and comorbid emotional alterations (i.e., anxiety and depression) [ 12 , 13 ]. Concerning cognitive deficits, FMS patients tend to exhibit difficulties in verbal memory, organization and planning abilities, strategic planning, self-regulation, processing speed, attention, and cognitive flexibility [ 9 – 11 ]. The remaining studies explored chronic tension-type headache (CTTH) and rats with global cerebral ischemia [ 14 , 15 ].…”

“…The first study [ 9 ], investigated executive functions in FMS patients compared with healthy controls via a Go/No-Go task. The variability of reaction time (RT)—by using traditional and ex-Gaussian parameters—was evaluated as a marker of executive function impairments.…”