Cerebral hemodynamics and behavioral responses during simulated driving with and without hands-free telecommunication: a Near Infrared Spectroscopy study

The aims of the present study were to comprehend the behavioral effects of hands-free telecommunication on the hemodynamic responses and examine their relationship with the driving errors during the intervention. To study cerebral hemodynamics (using Near Infrared Spectroscopy) during distracted driving, 26 male participants drove in a simulated urban scenario, without (4 minutes) and with (2 minutes) naturalistic conversation using a hands-free earpiece. Two trials of each intervention were conducted. Driving errors were counted; NIRS and heart rate data were collected. The results indicated that driving with hands-free telecommunication led to an increase in driving errors, neuronal activation of the left frontal lobe (evident by a significant increase in oxy-hemoglobin and decrease in deoxy-hemoglobin) and heart rate compared to driving without telecommunication. Changes in NIRS variables were not correlated with driving errors possibly due to heterogeneity of NIRS data.