a) Regardless of the activity-crossword puzzles,wood carving,playing a new musical instrument-you need to feel as if you are mentally sweating in order to really affect the brain, and that's regularly,no just once a month.The same holds true for your job. If you're not finding new challenges at work,you're not demanding your brain to create new cells.

b) Crosswords are better because they create brain cells throughout many key parts of the cerebral cortex,improving overall function.It also facilitates the production of new brain cells in the frontal lobe-the area responsible for executive functions such as the ability to organise thoughts,problem solve,and focus-by increasing the networks of fine blood vessels in that region.

c) The same holds true for your job.If you're not finding new challenges at work,you're not demanding your brain to create new cells.