Supra-second interval timing deficits and abnormal frontal theta oscillations in individuals with bipolar disorder

Abstract

Objectives: Though widely reported by patients, cognitive symptoms associated with bipolar disorder (BD), including deficits in executive function, memory, attention, and timing are under-studied. Work suggests that individuals with BD show impairments in sub-second interval timing tasks (ITT), however, results have been inconclusive regarding supra-second time perception in BD patients. Additionally, the effects of mood or medication status on time perception in BD patients are debated in the literature. Methods: To address this, the present work administered a supra-second ITT concurrent with electroencephalographic (EEG) recordings to patients with BD and neuronormative controls. As this task is known to elicit frontal theta oscillations, which can be abnormal in psychiatric populations, signal from the Fz lead was analyzed at rest and during the task. Results & Conclusions: As hypothesized, results suggest that individuals with BD show impairments in supra-second ITT performance compared to neuronormative controls. Frontal theta power was also reduced compared to controls during the ITT but not during rest. Finally, timing impairments remain detectible in BD patients independent of mood state and use of antipsychotic medication. This suggests that supra-second interval timing deficits are a key characteristic observed in BD. Together with previous work, these findings point to critical timing impairments in BD patients across a wide range of timing modalities and durations.