The psychobiology of using automated driving systems: A systematic review and integrative model

Using vehicles with engaged automated driving systems (ADS) ('highly automated driving', HAD) will substantially impact on future society's mobility, yet the current understanding of human psychobiology related to HAD is still limited. Hence, we synthesized evidence on the psychobiology of subjects using HAD, informing an integrative model of the psychobiology of HAD, and providing guidance for reporting future research on this topic. We included (non-)randomized studies assessing human peripheral biology markers of in-vehicle-users in real or simulated driving environments, using vehicles with vs. without engaged ADS, published in English until April 2018. We systematically searched Web of Science, SCOPUS, and PubMed. The search consisted of a combination of terms describing HAD and psychobiological parameters. Risk of bias was assessed regarding randomization, blinding, incomplete outcome data, selective outcome reporting, and other potential causes. We extracted data using predefined data fields. Four out of five studies included in this review (N = 194 subjects) reported associations of use of vehicles with vs. without engaged ADS with various psychobiological parameters, including heart rate, respiratory sinus arrhythmia (RSA), indicators of electrodermal activity (EDA), and masseter electromyography (EMG). Heart rate tended to be reduced during HAD along with increased EDA and EMG, with no clear indication for changes in RSA. We cannot exclude substantial risk of bias, among others because the status of engagement of ADS was mostly non-randomized. Yet, findings suggest that HAD goes along with tractable changes in peripheral biology. Informed by the conceptual endophenotype approach (Hellhammer et al., 2018, Psychoneuroendocrinology), we propose the Embodied Driving (EMBODD) model that describes how HAD reshapes vehicle use experience, and highlight how to make future ADS equipped vehicles successful regarding user's health. Based on the review, we suggest reporting guidelines for future research on the psychobiology of HAD.