Cognitive functions of shift workers: paramedics and firefighters – an electroencephalography study

Abstract

<i>Introduction</i>. Working shifts has a negative impact on employee health and cognitive efficiency. The purpose of this study was to investigate the impact of shift work on cognitive functions - attention and working memory - using both behavioural and electrophysiological measures. <i>Methods</i>. The study was carried out on a group of 34 shift employees (18 paramedics, 16 firefighters) and on 17 day workers. Participants performed the attention network test and the <i>N</i>-back task with two conditions (1-back, 2-back) while the electroencephalography signal was recorded. <i>Results.</i> Observations included a higher amplitude of the P200 potential in paramedics (compared to the control group), a higher amplitude of the P300 potential after work than on a day off and the lowest increase in power in the θ band after the night shift. In firefighters, lower α desynchronization and lower synchronization in the α/β band were observed after a 24-h shift. Paramedics and firefighters had longer reaction times (<i>N</i>-back task). <i>Conclusions</i>. The results suggest that paramedics experience problems with sustained attention. Paramedics process visual stimuli in a different way; after a night shift, performing the tasks required more engagement of cognitive resources. For firefighters, a decrease in visual attention functions and cognitive inhibition was observed.