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An automatic method for the classification of wakefulness and sleep stages SREM, S1, S2 and SWS was developed based on our two previous studies. The method is based on a two-channel electro-oculography (EOG) referenced to the left mastoid (M1). Synchronous electroencephalographic (EEG) activity in S2 and SWS was detected by calculating cross-correlation and(More)
The aim of the study was to compare saccadic peak velocity (SPV) values measured with video based Fitness Impairment Tester (FIT) and electro-oculography (EOG) during prolonged wakefulness. We tested different numbers of saccades and two saccade paradigms to improve the EOG measurements for detecting fatigue. The SPVs were measured from 11 fast patrol boat(More)
Subjects sense clear mechanical vibrations during diffusion tensor imaging (DTI). These vibrations, likely resulting from diffusion-sensitizing gradients, have been assumed to be of the same strength and phase in all parts of the magnetic resonance imaging (MRI) scanner so that they could be ignored. However, our measurements, carried out from several parts(More)
Modern work requires cognitively demanding multitasking and the need for sustained vigilance, which may result in work-related stress and may increase the possibility of human error. Objective methods for estimating cognitive overload and mental fatigue of the brain on-line, during work performance, are needed. We present a two-channel(More)
Variation of single-trial P300 responses was studied both in relation to reaction times and to the preceding stimulus sequence in an auditory oddball paradigm. Single-trial responses were estimated with the Subspace regularization method that is based on Bayesian estimation and linear modeling. The results of the single-trial method were compared to those(More)
Sleep in shift work has been studied extensively in regular shift systems but to a lesser degree in irregular shifts. Our main aim was to examine the sleep-wake rhythm in shift combinations ending with the night or the morning shift in two irregular shift systems. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers(More)
We studied how moderate to severe childhood traumatic brain injury (TBI) affects vocational outcome with time. This is the second follow-up of patients who were injured as preschoolers in traffic accidents. In the first follow-up the mean age was 23 years and in the present study the average age of the 27-patient cohort was 40 years. Twenty-two patients(More)
Standard sleep stage classification is based on visual analysis of central EEG, EOG and EMG signals. Automatic analysis with a reduced number of sensors has been studied as an easy alternative to the standard. In this study, a single-channel electro-oculography (EOG) algorithm was developed for separation of wakefulness, SREM, light sleep (S1, S2) and slow(More)
Dietary components may affect brain function and influence behaviour by inducing the synthesis of neurotransmitters. The aim of the present study was to examine the influence of consumption of a whey protein-containing breakfast drink v. a carbohydrate drink v. control on subjective and physiological responses to mental workload in simulated work. In a(More)
We studied the recovery of multitask performance and sleepiness from acute partial sleep deprivation through rest pauses embedded in performance sessions and an 8 h recovery sleep opportunity the following night. Sixteen healthy men, aged 19-22 yrs, participated in normal sleep (two successive nights with 8 h sleep) and sleep debt (one 2 h night sleep(More)