Final answer:
The association of language functions with the left hemisphere is established through lateralization and research on split-brain patients. While the left hemisphere is primarily responsible for language, the right hemisphere's role in language-related processes like swearing and emotion requires further investigation.
Step-by-step explanation:
The cerebral cortex's language functions are primarily associated with the left hemisphere in around 95% of the population. This hemispheric lateralization is pivotal for language processing and production. However, research into split-brain patients—those who have had their corpus callosum severed to treat severe epilepsy—reveals that the right hemisphere has unique functions as well. For instance, if a split-brain patient receives visual input in the left visual field, it's processed in the right hemisphere. Without access to the language centers typically located in the left hemisphere due to the severed corpus callosum, the patient may be unable to name objects seen in this way, even though they can select the object using their left hand.
Research provides insight into the specializations of each hemisphere. While the left is often connected with language, the right hemisphere is suggested to be superior in pitch perception and processing of negative emotions. These findings, such as those from split-brain patient studies, have led to the misconception that the right hemisphere might be the center for certain functions like swearing, which often is tied to emotion rather than structured language.
In conclusion, while the left hemisphere is crucial for language, there are cases where the right hemisphere might process certain types of language-related information. The exact mechanisms behind swearing and its lateralization in the brain require further research to fully understand any hemispheric dominance.