title: Physiological responses related to moderate mental load during car driving in field conditions.
abstract: We measured physiological variables on nine car drivers to capture moderate magnitudes of mental load (ML) during driving in prolonged and repeated city and highway field conditions. Ecological validity was optimized by avoiding any artificial interference to manipulate drivers ML, drivers were alone in the car, they were free to choose their paths to the target, and the repeated drives familiarized drivers to the procedure. Our aim was to investigate if driver's physiological variables can be reliably measured and used as predictors of moderate individual levels of ML in naturally occurring unpredictably changing field conditions. Variables investigated were: heart-rate, skin conductance level, breath duration, blink frequency, blink duration, and eye fixation related potentials. After the drives, with support from video uptakes, a self-rating and a score made by external raters were used to distinguish moderately high and low ML segments. Variability was high but aggregated data could distinguish city from highway drives. Multivariate models could successfully classify high and low ML within highway and city drives using physiological variables as input. In summary, physiological variables have a potential to be used as indicators of moderate ML in unpredictably changing field conditions and to advance the evaluation and development of new active safety systems.
authors: Volvo Car Corporation, Research and Development, Gothenburg, Sweden. Electronic address: hwiberg@volvocars.com.
authors: Henrik
authors: H
authors: Wiberg
authors: Volvo Car Corporation, Research and Development, Gothenburg, Sweden.
authors: Emma
authors: E
authors: Nilsson
authors: Volvo Car Corporation, Research and Development, Gothenburg, Sweden.
authors: Per
authors: P
authors: Lindén
authors: Volvo Car Corporation, Research and Development, Gothenburg, Sweden.
authors: Bo
authors: B
authors: Svanberg
authors: Department of Psychology, Uppsala University, Box 1225, SE-751 42 Uppsala, Sweden. Electronic address: leo.poom@psyk.uu.se.
authors: Leo
authors: L
authors: Poom
mesh_terms: D000328:Adult; D000465:Algorithms; D001334:Automobile Driving / Q000523:psychology*; D001767:Blinking / Q000502:physiology; D004777:Environment; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D005712:Galvanic Skin Response / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013315:Stress, Psychological / Q000523:psychology; D055815:Young Adult
keywords: Car driving; Field conditions; Mental load; Multivariate models; Physiology; Workload