Provided are a driving assistance device and a computer program that induce wakefulness by applying a stimulus at a predetermined timing prior to the onset of intense drowsiness like that which occurs during the phenomenon of impending sleep. In addition to applying a stimulus as in the prior art at a timing that corresponds to a warning that is issued when each of various biological states that appear concomitantly with a decrease in wakefulness is at a warning level, for example, a timing at which the phenomenon of impending sleep is detected while wakefulness is decreasing and drowsiness is increasing, the present invention applies a stimulus using a timing at which symptoms related to a decrease in wakefulness are detected prior to reaching the phenomenon of impending sleep, for example, when an indicator that is obtained by analysis while estimating that a driver has not yet reached the phenomenon of impending sleep indicates a period of increase with respect to the degree of fatigue or a period of continuation of the same biological state.
DRIVING ASSISTANCE DEVICE AND COMPUTER PROGRAM