Abstract: Apparatus and associated methods relate to capturing physiological data from a sensor configured in a user's wearable device while the user performs a task, individualizing the physiological data to the user based on comparison with historical user physiological data, measuring the user's cognitive function determined in relationship to the individual's physiological data, and automatically notifying the user of cognitive fatigue and performance detected based on evaluating the measured cognitive function over time. In an illustrative example, the wearable device maybe a gaming headset. The measured cognitive function may be, for example, determined as a function of electroencephalograph or heart rate variability data captured from a user while the user performs a task. Some examples may provide recovery recommendations based on the detected cognitive fatigue.