The primary function of the frontal lobe in the brain includes higher-level cognitive processes such as reasoning, decision-making, and problem-solving. It is also involved in emotional regulation and controlling behavior. This lobe plays a key role in the execution of voluntary movements and coordination. Additionally, the frontal lobe's prefrontal cortex is crucial for social interactions and personality expression. Disruptions in this area can lead to difficulties in planning and judgment, highlighting its importance in daily functioning and overall mental health.