Matthew 15:18 James 3:6 In general, the left hemisphere of the brain is dominant in language: processing what you hear and handling most of the duties of speaking. It's also in charge of carrying out logic and exact mathematical computations. When you need to retrieve a fact, your left brain pulls it from your memory. The right hemisphere of the brain is mainly in charge of spatial abilities, face recognition and processing music. It performs some math, but only rough estimations and comparisons. The brain's right side also helps us to comprehend visual imagery and make sense of what we see. It plays a role in language, particularly in interpreting context and a person's tone.