What significant finding was revealed through Paul Broca's patient autopsy?

The significant finding from Paul Broca's patient autopsy was a lesion in the left hemisphere's frontal lobe. This conclusion was derived from the case of "Tan," a patient who suffered from expressive aphasia, which is a condition characterized by difficulty in producing speech despite having intact comprehension abilities. Broca examined Tan's brain after his death and identified a specific area of damage in the left frontal lobe, which later became known as Broca's area.

This discovery was crucial in establishing the relationship between brain structure and language functioning, indicating that specific regions of the brain are responsible for specific cognitive functions like speech production. It provided one of the earliest pieces of evidence for the localization of brain function, particularly in relation to language. Broca's findings significantly contributed to the understanding of the neurological basis of language and cognition, highlighting the importance of the frontal lobes in these processes.