Meanwhile, scientists are trying to understand why the brain deteriorates over time, losing mass and neural circuitry.

Neural circuitry involved with processing fresh evidence seems to grind to a halt, making it less likely that we will change our mind.

This distinction, when combined with a suite of other changes to our tongue and our neural circuitry (all outlined in detail), explains why we alone can form words.

It spans many levels of analysis, from low-level learning and decision mechanisms to high-level logic and planning; from neural circuitry to modular brain organization.

A medley of studies have started to investigate the differences between these steps in humor processing and the neural circuitry that underlie these mechanisms.