Studies on aphasia are examples of studies on cognitive processes of the brain.

Aphasia is often caused by brain damage, and refers to the inability to understanding the content of speech and/or produce speech. There are numerous kinds of aphasia, two of which are Broca’s aphasia and Wernicke’s aphasia.

Broca’s area

Broca’s area is located in the left frontal lobe (in the prefrontal cortex). It is responsible for the production of language and speech, specifically the movement of the muscles in the face which allows one to speak. Damage to Broca’s area may lead to Broca’s aphasia:

Broca’s aphasia

An individual experiencing Broca’s aphasia would have difficulty in the physical processes of producing speech. Whilst the individual may be capable of producing a few words (mainly simple content words), a lot of mental effort would be required. Broca’s aphasia does not impact comprehension of language, meaning that a sufferer would be capable of understanding what you have said, capable of thinking about how they want to reply, but incapable of actually producing those words. An individual suffering from Broca’s aphasia is highly likely to be aware of their condition.

Wernicke’s area

Wernicke’s area is usually located in the left temporal lobe, however it may be present in the right temporal lobe at times (more likely for left handers). It is responsible for the comprehension of language and speech, specifically using the correct words at the correct time. Damage to Wernicke’s area may lead to Wernicke’s aphasia:

Wernicke’s aphasia

An individual experiencing Wernicke’s aphasia would have difficulty in the sensical comprehension of language. Whilst the individual’s physical production of speech is unaffected and their speech remains fluent, they are incapable of linking together words or ideas in a logical way. Subsequently, the content of their speech may be non-sensical and very confusing. An individual suffering from Wernicke’s aphasia is unlikely to be fully aware of their condition, meaning that they may believe that they understand or that they are making sense when, in reality, they are not.

Broca’s area and Wernicke’s area are roughly shown on the diagram below.

broca wernicke