Who can? It isn't a decision that your conscious mind is able to make. Deciding not to decide is still deciding. As they say in Ch'an buddhism, you can't wash off blood with more blood.

This is where meditating, especially meditative physical disciplines like T'ai Chi Ch'uan, come in handy. They engage the mind and keep it busy long enough for the heart and body to take over for a minute or two. In a perfect situation, over time, you'll get better at paying more attention to your heart than your brain and not only will you feel better, you'll get better at it and eventually understand it well enough to teach others how to do it.