How can you expand a brush point with keyboard?

How can you expand a brush point with keyboard?
In order to increase or decrease the size of your brush, you need to:

Click and hold the Alt key. (On Mac, this would be the Ctrl and Alt keys),
Click and hold the right mouse button,
Then drag horizontally from left to right to increase, and from right to left to decrease the size.

In order to increase or decrease the size of your brush, you need to:
  1. Click and hold the Alt key. (On Mac, this would be the Ctrl and Alt keys),
  2. Click and hold the right mouse button,
  3. Then drag horizontally from left to right to increase, and from right to left to decrease the size.