Advances in sleep science are often dependent on improving the tools and techniques used for measuring sleep.
This area of work has involved comparing different methods for measuring the sleep of flight crew, ranging from the gold standard measure of polysomnography to subjective reports. We found that for estimating mean sleep duration, both actigraphic and subjective estimates are sufficiently close to polysomnographic values, but any single estimate may vary by more than 1 h from the mean difference. Neither actigraphy nor subjective estimates are suitable for estimating sleep efficiency and latency. Findings indicate that the performance of the actigraph is not altered in flight, other than the predictable effects associated with shorter, more disturbed sleep. The metrics used to compare one measurement tool to another are also important.
Other work has focused on the consequences of identifying and removing artefact from electro-encephalography recordings taken in the work place to determine an individual’s level of alertness. Our findings show that artefact in recordings must be carefully considered, managed, and clearly reported in workplace EEG studies as its inclusion in recordings can alter study outcomes.
We have also previously collaborated with researchers from the New Zealand Brain Research Institute to investigate the detection of lapses of attention and drowsiness using electrophysiological signals (EEG, EOG) and fMRI.
At present we are conducting an evaluation of the sensitivity of the sleep and performance measures used for monitoring pilot fatigue in operational settings. We are investigating whether measures of in-flight sleep recorded with polysomnography are more sensitive predictors of psychomotor vigilance performance near top of descent than measures of sleep recorded with actigraphy, and if fatigue-related impairment differs between performance measures derived from the 5 and 10 minute psychomotor vigilance task test.
