Decision fatigue is the mental and emotional exhaustion that results from making too many choices throughout the day.
High-level reasoning is metabolically “expensive.” Every time a person exerts willpower or make a choice, they utilize resources in the prefrontal cortex. As these resources are taxed, the prefrontal cortex’s ability to exert “top-down” inhibition over other brain regions weakens, which explains why you a person might snap at a colleague or buy junk food after a long day of meetings—the “logical filter” is essentially offline.