India, Nov. 14 -- Turns out, your brain might actually remember things better when it's running low on energy. Researchers at Japan's Tohoku University say memory formation doesn't stay the same all day; it moves on a kind of internal clock. Their study found that fatigue, instead of slowing the mind, might actually help it form stronger long-term memories.

The team studied rats and found that the brain's response to the same signal changed depending on the time of day. What surprised them was that when the rats were at their most tired, right before sunrise, their brains were more prepared to store new information. In short, weaker short-term responses didn't mean poor learning. It meant the brain was in a state that helped memories sti...