Have you ever felt like this? As if your brain simply cannot take in one more thing?

Has thinking exhausted your brain?

Here are the facts:

1. The brain consumes about 20% of the body’s energy, despite representing only 2% of its weight. (Calculated using oxygen consumption).

2. Increased mental activity mainly for information processing does lead to slightly higher energy consumption, but this increase is minimal, brain region-specific, and is often offset by energy decreases in other areas. Even in seemingly idle-mind states, the brain is constantly processing sensory input, engaging in mental activity, and experiencing emotions.

3. Feeling exhausted after mental activity is more likely to be due to mental stress rather than actual energy depletion. Mental stress increases oxygen consumption, and exhaustion can also be due to the whole body reacting to emotional or stressful situations. When this happens, the sympathetic nervous system is activated resulting in mental and physical fatigue.

4. The increase in brain activity for simple tasks like paying attention is minimal and is often offset by energy decreases in other areas of the brain.