PT Journal AU Gale, J Signal, TL Garden, AL Gander, PH TI Electroencephalography artifacts in workplace alertness monitoring SO Scandinavian Journal of Work, Environment & Health PD 4VL PY 2007 BP 148 EP 153 IS 2 DI 10.5271/sjweh.1119 WP https://www.sjweh.fi/show_abstract.php?abstract_id=1119 DE alertness monitoring; digital signal processing; electroencephalography artifact; night work; shift work; sleepiness; workplace SN 0355-3140 AB '

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OBJECTIVE ': 'This study assessed the effect of removing artifacts from workplace electroencephalography (EEG) recordings on power spectra and the consequent interpretation of changes in alertness.

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METHODS ': 'EEG was recorded for 27 air traffic controllers on the night shifts of four roster cycles. On two of the four night shifts, each controller was given a 40-minute opportunity to nap, while on the other two they remained awake (105 shifts in total). Recordings for the last hour of each night shift were screened for artifacts by an experienced viewer (who viewed the EEG in isolation from other electrophysiological recordings). The effects of the nap opportunity on the EEG power spectra were then analyzed in a mixed model analysis of variance in the presence and absence of artifact-contaminated data.

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RESULTS ': 'Overall, 89.3% of the EEG recordings contained artifacts. Removal of these data markedly altered the interpretation of how the nap opportunities affected the EEG power spectra. The spectral parameters of the artifact appeared to be different when the participants were given the opportunity to nap.

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CONCLUSIONS ': 'Removal of artifacts can dramatically affect the interpretation of workplace EEG recordings. This potential source of error is often unreported.

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