The heart is in a two-way correlation with the brain. With regards it is true to say our emotions change the the functioning of our hearts but not the shape. The signals that the brain sends to the heart responds in complex ways. For instance, when in fear, stress or excited, our heart beat paces. In a other words, these signals create the actual feelings we experience in our hearts and the body as a whole. The shift in our heart's rhythms also determines our ability to think or reason clearly.