The pupil as a possible premonitor of drowsiness

Abstract

Prediction of drowsiness based on an objective measure is demanded in machine and vehicle operations in which human errors may cause fatal accidents. Currently we focused on the pupil of the eye which is controlled by the autonomic nervous system, and easily observable non-invasively from the outside of the body. We employed uneventful driving simulation to induce drowsiness of human subjects, and an anti-saccade task to evaluate their cognitive and motor performance. First we confirmed that pupil diameter fluctuates with large amplitude at low frequencies when the subject is aware of his/her drowsiness as reported previously. During this period, the latency of anti-saccade initiation was elongated and varied. We then found that prior to this fluctuation, pupil diameter decreases gradually in most subjects, and they were not aware of sleepiness during this period. We conclude that this monotonic gradual miosis can be a reliable premonitor of drowsiness.

Pupil fluctuations track rapid changes in adrenergic and cholinergic activity in cortex

“…Human and animal studies demonstrate that non-luminance and non-accommodation changes in pupil diameter are related to a wide variety of mental and emotional factors, including arousal, attention, stress and cognitive load, and reveal a tight coupling between the state of the central and peripheral nervous systems12122232425262728293031323334353637383940.…”

Detecting deteriorated vigilance using percentage of eyelid closure time during behavioral maintenance of wakefulness tests

“…First, this study did not investigate the relation between spontaneous pupillary oscillations (Henson and Emuh, 2010;Nishiyama et al, 2007;Wilhelm et al, 1998) and error profiles because consecutive points of missed pupil data in the epochs with longer consecutive errors were too long to interpolate a value into a series of pupil diameters by calculating results from surrounding raw pupil data. Second, we were unable to investigate the modest deterioration of vigilance weaker than we measured in this study.…”

Waking State: Rapid Variations Modulate Neural and Behavioral Responses

“…In parallel work, over the last 50 years, waking brain state has been assessed in psychophysical experiments by monitoring the diameter of the pupil (Hess and Polt, 1960, 1964; Kahneman and Beatty, 1966). Human and animal studies have shown that changes in pupil diameter (after controlling for changes associated with luminance and depth accommodation) are correlated with arousal, attention, emotion, cognitive perception, “brain gain”, as well as heart rate and galvanic skin reflex, indicating a tight coupling between the state of the central and peripheral nervous systems (Alnaes et al, 2014; Bradley et al, 2008; de Gee et al, 2014; Einhauser et al, 2010; Einhauser et al, 2008; Eldar et al, 2013; Gilzenrat et al, 2010; Hess and Polt, 1960, 1964; Iriki et al, 1996; Jepma and Nieuwenhuis, 2011; Kahneman and Beatty, 1966; Murphy et al, 2011; Murphy et al, 2014b; Nassar et al, 2012; Nishiyama et al, 2007; Onorati et al, 2013; Preuschoff et al, 2011; Tursky et al, 1969; Wierda et al, 2012; Wilhelm et al, 2001). In human studies, drowsiness during the performance of a routine task, such as simulated driving, can be associated with wide variations in arousal and performance that are reflected by large fluctuations in pupil diameter (Kristjansson et al, 2009; Wilhelm et al, 2001).…”