Why you should stop thinking too hard?

A recent study published in Current Biology has shown that thinking more than normal can lead to the development of toxic chemicals in the brain.

When the brain remains active for longer periods of time, it shifts to a mode that does not require much effort so that the chemical glutamate circulates less in the body.

As a result, neuroscientists from Pitié-Salpêtrière University in Paris, France say that a person may lose the drive to work (cognitive fatigue). 

The lead author of the study Dr Mathias Pessiglione said that some theories strongly suggested that fatigue was an illusion created by the brain to stop a person from working and going for more satisfying activity.

Researchers said cognitive work causes functional alteration which is the accumulation of toxic substances. Brain makes attempts to preserve optimal brain functioning.

Glutamate is a neurotransmitter which activates excitatory functions in the brain.

For good brain functioning, there should be glutamate in the body but in the right concentration at the right time.

An excess of this neurotransmitter can cause diseases like Parkinson's, Alzheimer and Huntington's.

Strenuous manual labour causes physical fatigue. Overthinking can lead to serious mental exhaustion further leading to the loss of ability to concentrate.

Researchers performed magnetic resonance spectroscopy (MRS) on two groups of people over the course of a workday.

One group was given easy computer-based memory tasks and the other was given difficult ones. 

People with more difficult tasks went for options that required lower effort and gave smaller rewards. Findings also showed that these people had more glutamate in their synapses of the brain's prefrontal cortex.