What Part of the Brain Controls Speech

Talking is our main form of communication and what a quiet world this would be if no one could speak! So what part of the brain controls speech? That would be a section of our frontal lope that is referred to as Broca's area.

The brain is divided into two parts, the right and the left... so you basically have a right frontal lobe and a left frontal lobe and both sections are located in the front part of the brain. Broca's area that controls speech is a small section that is located at the bottom of the left frontal lobe.

Even though Broca's area is known for speech production, it was discovered that it also plans, organizes and ranks our behaviors... from things as simple as planning a meal to as complex as planning a mission to Mars. Apparently when a person uses their planning and organizing skills, Broca's area in both sides of the frontal lobe are activated and this accounts for its major role in the production of language.

Speech may be a function that is preformed by the left frontal lobe, but the right frontal lobe also contributes, and if the left frontal lobe happens to be damaged in childhood, the right will take over the speech function. It has also been discovered that there are some people whose speech function is on the right side and some have this function on both the right and left sides of their frontal lobes.

Broca's area is responsible for the motor movements that are necessary to preform speech, but it does not cause the movements. This is done when signals from this area are sent to the motor strip, which then sends the signals to the cranial and spinal nerves which sends them on to your muscles.

Discovery of Speech in the Frontal Lobe (Broca's Area)

A French neurologist by the name of Marc Dax made the conclusions a generation earlier, that the frontal lobe was responsible for the production of speech, but it was the work of Pierre Paul Broca, a French anatomist, anthropologist, and surgeon that receives the credit. Mr. Broca concluded that speech was also a production of the frontal lobe when he did studies on aphasic patients. These are patients with a language impairment.

In 1861, Mr. Broca did an autopsy on the brain of a deceased aphasic patient and discovered lesions caused by syphilis. It was concluded that these lesions were on the part of the brain that was responsible for speech production.

What Happens if the Frontal Lobe (Broca's Area) is Injured

Speech disorders can be caused by many things, but any damage or injury to Broca's area will have an affect on the muscles of the vocal cords, the tongue, the lips and the jaw, and this in turn may prevent the person from producing understandable speech, which is aphasia.

People who suffer damage, lesions or scarring on this structure may have trouble getting their thoughts across in writing and speaking. They may also have trouble finding the word they need, trouble articulating, they will repeat words and not be able to produce sentences that you can understand.

Some Disorders that Affect the Frontal Lobe (Broca's Area)

Aphasia
This is the term used when damage has occurred to the part of the brain that controls speech, and the person has lost either part or all of their ability to talk or understand spoken or written words.

Frontotemporal Dementia
People suffering from this illness may not be able to find the words they need when talking. There will be language deterioration, they suffer from restlessness, are overactive and some will become apathetic and inert.

Stroke
If the left side of the brain - where Broca's area is located - was affected during the stroke, the person will have problems with their speech and may also have trouble expressing their thoughts in writing or speaking. If the stroke affected the part of the brain that controls the muscles in the mouth, lips or tongue, then their speech will be slurred.

Huntington's Disease
This disease primarily affects the frontal and temporal lobes. A person with this disease will have problems with their coordination, concentration, memory, judgment and their emotions. Areas deeper in the brain that are responsible for motor function and control will also be affected and the person may have problems swallowing, problems with their balance, movement and their speech.

Parkinson's Disease
A person suffering from Parkinson's disease will have the symptoms that are associated with aphasia, which is losing their ability to speak and understand the written word.

Brain Tumors
If Broca's area is affected, the person will exhibit communication disorders like finding the right word to use... along with the other symptoms of a brain tumor - which are headaches, vomiting, change in your vision, seizures, weakness in limbs and nausea.

Brain Injuries
Any brain damage or injury in Broca's area will disrupt the person's speech. See the explanation for aphasia.

Alzheimer's Disease
This disease generally starts with the memory then works its way to the area of the brain responsible for language and visual processing. People will have problems naming objects, problems speaking fluently, and problems speaking in complete sentences because they can not find the right word. At the end stage of the disease, people will also have problems with speech comprehension.

Corticobasal Degeneration
This is another disease that will affect the person's ability to speak in complete sentences because they can not find the right word. They will have trouble articulating and their writing and reading may also be compromised.