Effects of total sleep deprivation on divided attention performance

Abstract

Dividing attention across two tasks performed simultaneously usually results in impaired performance on one or both tasks. Most studies have found no difference in the dual-task cost of dividing attention in rested and sleep-deprived states. We hypothesized that, for a divided attention task that is highly cognitively-demanding, performance would show greater impairment during exposure to sleep deprivation. A group of 30 healthy males aged 21-30 years was exposed to 40 h of continuous wakefulness in a laboratory setting. Every 2 h, subjects completed a divided attention task comprising 3 blocks in which an auditory Go/No-Go task was 1) performed alone (single task); 2) performed simultaneously with a visual Go/No-Go task (dual task); and 3) performed simultaneously with both a visual Go/No-Go task and a visually-guided motor tracking task (triple task). Performance on all tasks showed substantial deterioration during exposure to sleep deprivation. A significant interaction was observed between task load and time since wake on auditory Go/No-Go task performance, with greater impairment in response times and accuracy during extended wakefulness. Our results suggest that the ability to divide attention between multiple tasks is impaired during exposure to sleep deprivation. These findings have potential implications for occupations that require multi-tasking combined with long work hours and exposure to sleep loss.

Fig 1. Effects of sleep deprivation on divided attention performance.

Subjects completed (1) a single task consisting of an auditory Go/No-Go (aGNG) task, (2) a dual task in which the aGNG task was taken while simultaneously performing a visual Go/No-Go (vGNG) task, and (3) a triple task which included the aGNG and vGNG tasks, as well as a motor tracking task in which participants were required to maintain a cursor on a moving target. (A) The time course of reaction times on the aGNG task is shown during 40 h of sustained wakefulness for single (black circles), dual (white circles) and triple (gray circles) task conditions. (B) The increase in aGNG reaction times is shown during dual-task and triple-task conditions relative to the single-task condition. (C) The time course of errors on the aGNG task is shown during single, dual, and triple task conditions. (D) The increase in the number of errors is shown during dual-task and triple-task conditions relative to the single-task condition. The vertical gray box in each plot shows the usual hours of sleep. In panels A and C, hash marks (#) show significant differences in performance between single and dual tasks; ampersands (&) show significant differences between single and triple tasks; and asterisks (*) show significant differences between dual and triple tasks. In each plot, the mean ± SEM is shown.

Fig 2. Effects of sleep deprivation on visual Go/No-Go and motor tracking performance.

Subjects completed a dual task in which a visual Go/No-Go (vGNG) task was performed at the same time as an auditory Go/No-Go (aGNG) task, and a triple task that included aGNG and vGNG tasks, as well as a motor tracking task. The time course of (A) reaction times and (B) errors on the vGNG task is shown during 40 h of sustained wakefulness for dual (white circles) and triple (gray circles) task conditions. (C) The time course for tracking accuracy is shown for the motor tracking task in the triple-task condition. The vertical gray box in each plot shows the usual hours of sleep. In each plot, the mean ± SEM is shown.