Nine dots are arranged on the sides and the center of a square as in the picture below. The problem is to connect the dots with no more than 4 straight lines.  Go ahead and try to solve this. 

In recent years there has been a wave of NIH sponsored research that supports the idea that binaural beats change the brain’s state.    

The word “binaural” means relating to or used by both ears. "Binaural beats" describes a change in brain activity while listening to two slightly different tones in stereo.