Final answer:
The left-frontal lobe is primarily involved in language production and processing, while the right-frontal lobe handles nonverbal aspects of communication and emotional expression in speech. Damage to either side can result in specific language impairments or affect nonverbal communication abilities.
Step-by-step explanation:
The role of the left-frontal lobe and right-frontal lobe in verbal and non-verbal language is quite distinct. The left-frontal lobe is primarily responsible for language functions, which include speech production, language processing, and expressive language abilities. This is why damage to the left side of the brain, particularly the frontal and temporal regions, can lead to types of aphasia. These disruptions can impact the ability to use certain types of words, known as V (verb) impairment or N (noun) impairment. On the other hand, the right-frontal lobe is associated with nonverbal aspects of communication, such as understanding figurative language, facial expressions, body language, and the emotional tone in speech. Damage to this region can affect nonverbal communication skills, resulting in a flat affect, or a robotic tone in speech, indicating a lack of emotional expression.