Find peer-reviewed, published research using the Inquisit Math Effort Task (MET)
Engle-Friedman, M., Riela, S., Golan, R., Ventuneac, A. M., Davis, C. M., Jefferson, A. D. and Major, D. (2003).
The effect of sleep loss on next day effort. Journal of Sleep Research, 12: 113–124
Johnson, A., & Brown, Kathleen. (2006). The Influence of Sleep Deprivation on Performance and the Occurrence of Error in Staff Nurses Who Work the Night Shift, ProQuest Dissertations and Theses.
Engle-Friedman, M., Riela, S., & Strothers, E. (2008). Objective and Subjective Effort as a Function of Sleep and Energy. Sleep and Hypnosis, 10(2), 61-72.