Abstract
Greater intra-individual variability (IIV) in reaction time (RT) on a sustained attention task has been reported in patients with bipolar disorder (BD) compared with healthy controls. However, it is unclear whether IIV is task specific, or whether it represents general cross-task impairment in BD. This study aimed to investigate whether IIV occurs in sustained attention tasks with different parameters. Twenty-two patients with BD (currently euthymic) and 17 controls completed two sustained attention tasks on different occasions: a low target frequency (~20%) Vigil continuous performance test (CPT) and a high target frequency (~70%) CPT version A-X (CPT-AX). Variability measures (individual standard deviation and coefficient of variation) were calculated per participant, and ex-Gaussian modeling was also applied. This was supplemented by Vincentile analysis to characterize RT distributions. Results indicated that participants (patients and controls) were generally slower and more variable when completing the Vigil CPT compared with CPT-AX. Significant group differences were also observed in the Vigil CPT, with euthymic BD patients being more variable than controls. This result suggests that IIV in BD demonstrates some degree of task specificity. Further research should incorporate analysis of additional RT distributional models (drift diffusion and fast Fourier transform) to fully characterize the pattern of IIV in BD, as well as its relationship to cognitive processes.
Highlights
Bipolar disorder (BD) is a severe and heterogeneous mood disorder [1]
Average response time was slower for the Vigil continuous performance test (CPT) compared with the CPT version A-X (CPT-AX)
Variability as measured by coefficient of variation (CoV) was higher in the CPT-AX task (M = 26.33, SE = 1.38) compared with Vigil (M = 19.50, SE = 0.98)
Summary
Bipolar disorder (BD) is a severe and heterogeneous mood disorder [1]. The disorder is associated with marked neurocognitive problems during mood episodes [2, 3], and in full symptomatic recovery. Processing speed, executive functioning, and sustained attention appear to be affected [e.g., Ref. Neurocognitive problems are considered a core feature of the disorder [8] and are related to lower quality of life [9]. There is interest in developing our understanding of potential cognitive endophenotypes [10], which may have benefits for diagnosis and treatment. Sustained attention – the ability to maintain concentration over a period of time [11] – is considered a potential cognitive endophenotype of BD [12].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
