Recent research has challenged the idea that the brain becomes fatigued simply from using up energy. In 2022, scientists conducted a study to investigate cognitive fatigue. Participants were asked to perform thinking tasks for 6 hours, with one group doing easy tasks and another doing hard tasks. The researchers measured biochemical changes in the participants' brains throughout the study.
They found that when volunteers performed difficult tasks, there were higher concentrations of glutamate in the lateral prefrontal cortex, the brain region associated with cognitive control. Glutamate is an excitatory neurotransmitter that triggers neurons to fire. Scientists believe that the accumulation of glutamate may make it harder for the prefrontal cortex to carry out activities like planning, decision-making, and learning.
Glutamate levels decrease during rest or sleep. Researchers speculate that when thinking makes you feel tired, it's your brain signaling that you need a break to maintain its function. Future research into glutamate levels in the brain could potentially help scientists develop ways to prevent burnout.
Vocabulary:
• Cognitive (adjective): Related to the mental processes of perception, memory, judgment, and reasoning
• Fatigue (noun): Extreme tiredness resulting from mental or physical exertion
• Glutamate (noun): An important neurotransmitter in the brain
• Neurotransmitter (noun): A chemical substance that transmits nerve impulses across a synapse
• Prefrontal cortex (noun): The front part of the frontal lobe in the brain, involved in complex cognitive behavior and decision making
• Speculate (verb): To form a theory or conjecture without firm evidenceSource: The Economist