Summary: A new PLOS ONE study reveals that regardless of the time of day, people experience a loss of motivation for completing a single task over its duration.
Our self-control may not be a finite resource that diminishes throughout the day, but we may still experience fatigue while persisting in a single task, according to a study published September 20, 2017 in the open-access journal PLOS ONE by Daniel Randles from the the University of Toronto, Canada and colleagues.
Previous studies have suggested that we have a finite resource of self-control, and thus have theorized that our motivation for cognitively challenging activities will deplete throughout the day. However, recent attempts to demonstrate people losing motivation on tasks throughout an entire day have failed to yield sufficient evidence to support this theory.
To investigate whether we have a finite amount of self-control, Randles and colleagues monitored two groups of students (N1 = 8,867, N2 = 8,754) over separate 17-week intervals with 24-hour coverage, as they engaged in voluntary learning and self-testing using an online program. The researchers assessed what time the students logged into the program, how long they persisted at a session, and how successful they were at the memory tests, and constructed a model from this data.
The researchers found that time of day had very little effect on students’ success at completing the tasks, which is contrary to the theory that our self-control depletes throughout the day. The researchers found that a student could concentrate on a single task for about an hour before their performance depleted on that specific task, which is consistent with previous research, but the time of day at which the task was performed did not affect performance.
In order to access this information, this study did not consider demographics or what the students thought about the task, which the authors suggest would be important details to allow for a more complete interpretation of the results. However, they maintain that this research casts some serious doubt on the theory that we have a limited reservoir of self-control to draw from throughout the day, and hopefully opens the door for additional studies on motivation.
Source: Tessa Gregory – PLOS
Image Source: NeuroscienceNews.com image is credited to Randles et al (2017).
Original Research: Full open access research for “A pre-registered naturalistic observation of within domain mental fatigue and domain-general depletion of self-control” by Daniel Randles, Iain Harlow, and Michael Inzlicht in PLOS ONE. Published online September 20 2017 doi:10.1371/journal.pone.0182980
A pre-registered naturalistic observation of within domain mental fatigue and domain-general depletion of self-control
Self-control is often believed to operate as if it were a finite, domain-general resource. However, recent attempts to demonstrate this under transparent conditions have failed to yield positive results. In the current study, we monitor two groups of students (N1 = 8,867, N2 = 8,754) over separate 17-week intervals with 24-hour coverage, as they engage in voluntary learning and self-testing using an online program. We use daily behavior to assess whether time-of-day effects support domain-general theories of self-control. Additionally, we assess whether mental fatigue emerges within task during prolonged persistent effort. Results reveal within-task fatigue emerges within an hour on-task. However, there is a negligible effect on ability throughout the day. Additionally, time-of-day has no detrimental effect on motivation; rather there is a strong tendency to increase learning time at night. Results are consistent with theories indicating people lose motivation within a specific task, but at odds with theories that argue for a domain-general self-control resource.
“A pre-registered naturalistic observation of within domain mental fatigue and domain-general depletion of self-control” by Daniel Randles, Iain Harlow, and Michael Inzlicht in PLOS ONE. Published online September 20 2017 doi:10.1371/journal.pone.0182980