Speaking and the comprehension of language are one of the most important cognitive skills of the human brain.
Wernicke’s area is an area in the back parts of the cerebral cortex which is specialized in the control of language, as well as the comprehension of spoken words.
In other words, the cognitive efforts we make during conversation are processed and translated in Wernicke’s area, which in turn gives us fluency in speech.
Where Is the Wernicke’s Area Located?
This brain center for speech production and language recognition and comprehension is located in the temporal lobe of the dominant side of the individual, typically the left one. It consists of motor neurons that are involved in the comprehension of speech.
On the upper side, Wernicke’s area is connected to the angular gyrus located in the parietal lobe, which also aids the processing of numbers and language, as well as reasoning and memory operations. It uses sensory information in order to comprehend language.
More specifically, Wernicke’s area is located in Brodmann’s area 22, i.e. the back part of the superior temporal gyrus of the two brain hemispheres. It surrounds the auditory cortex on the sulcus located on the side part of the brain and it is responsible for the processing and regulation of language and auditory stimuli.
What Is the Structure And Function of Wernicke’s Area?
Brodmann area 22 forms the Wernicke’s area, together with Brodmann area 42 in the temporal lobe. The middle temporal gyrus separates it from both the primary and secondary auditory cortex. It’s the place where the complex processing of language and audio stimuli occurs.
This area functions in relation to the right part of the brain (or the dominant part of the individual) and is responsible for the non-verbal processing of sounds. Also, it processes the lexical-semantic structures of language, thus regulating the production of sentences and complex sounds.
The gyri which comprise Wernicke’s area contribute to linking the words into meaningful and logical sentences.
How Do We Comprehend Speech and Language?
Language is a system of symbols with special meanings attached to them. It includes both the spoken and the written form of the symbols, i.e. letters and words.
The production of speech is a complex mental process regulated in the Wernicke’s area of the brain by which thoughts are translated into words. By assigning meaning to each distinguished sound of a language, these auditory stimuli are further converted into linguistically meaningful units that constitute speech.
From the translation of the sensory stimuli into meaningful lexical units to the physical production of meaningful sentences, Wernicke’s area plays one of the most important roles in the cognitive processes of the human brain, especially regarding speech and language.
What Are the Elements of Speech?
Speech consist of the following elements:
- Articulation – The physical (mechanical) production of linguistic sounds by the motor cortex located in the frontal lobes of the brain.
- Voice – The sound created by the vocal folds and through breathing. The air which passes through the upper respiratory system and the larynx causes the vocal folds to vibrate, thus producing our voice.
- Fluency of speech – The continuity, smoothness, grammatical correctness, and effortlessness of speech.
- Prosody – The pitch of the voice, as well as the stress on words, and the length of sounds are the elements which contribute added meaning to the linguistic units of speech. Often, the prosody assigns an emotional tone to the utterance.
What Is the Decoding of Speech And Language?
Wernicke’s area receives information from the sensory stimuli in the form of words, parts of speech, syllables, phrases, and sentences.
The utterance reaches our auditory system. Here, these units of speech are distinguished and identified as separate meaningful units of a language and differentiated from the other sounds.
In this way, we can relate them to their specific meaning. This part of the process is labeled as decoding.
What Happens During the Segmentation of Speech And Language?
Next, Wernicke’s area mediates between the processed meaning of what has been said and the sound stimuli which are exchanged between the speakers during the process of verbal communication.
This is followed by the process of segmentation. During this process, the dedicated area of the brain distinguishes the parts of speech. Prosody is the key feature for the segmentation of sounds.
What Are Phonemes?
Furthermore, when the sounds are being decoded in regard to speech, they are referred to as phonemes.
In other words, they are the smallest linguistically meaningful units of a language that are perceived as a distinct sound to which a meaning is assigned. This, in turn, leads to a lexical identification of the uttered sounds.
How Does Broca’s Area Help the Formation of Speech And Language?
Finally, with the help of the processes that happen in Broca’s area, the articulation of those lexically meaningful sounds can be performed, i.e. the speech is produced.
The production of speech is a complex process in which the phases occur in a specifically determined order, i.e. incrementally. Considering the fact that it regulates the motor production of words, Broca’s area is included in the formation of speech right before we utter the words.
How Is the Broca’s Area Different From the Wernicke’s Area?
Even though both the Broca’s area and the Wernicke’s area of the cerebral cortex play a part in the production of speech, they also both function on the individual’s dominant side of the brain (usually the left one).
However, while Wernicke’s area is dedicated to the cognitive function of understanding speech, the Broca’s area performs the physical function of the production of speech.
Wernicke’s area assigns meaning to sounds, i.e. the uttered words we hear. It’s the area of the brain where language develops in the first place, prior to being reproduced by the processes developed in Broca’s area.
Broca’s area is the part of the brain which is responsible for the correct word order and grammar of the utterance, as well as of the motor production of speech. These elements give fluency to spoken language.
What Happens if Wernicke’s Area Is Damaged or Dysfunctional?
As Wernicke’s area is a brain center for the regulation and control of speech, damage or dysfunctionality of this part of the cerebral cortex can lead to severe impairment in language development.
Direct damage in the Brodmann 22 area caused by a cerebral abscess, neoplasm, encephalitis, or seizures, can make the affected individual use improper substitutes for words (for instance, lemon for the sun, or fable for table).
Furthermore, one of the most common disorders of the brain due to damage to Wernicke’s area is aphasia.
Aphasia is a medical condition when the ability to read, write, speak, and comprehend language is impaired. Most often, it occurs after an injury to the language centers of the brain located in the left (or dominant) hemisphere.
The following causes can also contribute to it:
- Stroke
- Traumatic brain injury
- Brain tumor
- Brain injury
- Brain infections
- Dementia
- Alzheimer’s disease
What Are the Different Types of Aphasia?
There are several types of aphasia:
- Broca’s aphasia – A language disorder that is diagnosed when the affected person is unable to fluently connect parts of speech. The individual knows what he or she wants to say, and understands what other people are saying, yet, the production of speech requires an enormous effort on their behalf.
- Wernicke’s aphasia – The affected person is unable to understand both spoken and written language. The individual is able to utter long sentences, but they are usually made up of unnecessary or even invented words that lack meaning.
- Global aphasia – A severe language disorder characterized by an impairment of speech, where the affected individual has immense difficulty in both the production and understanding of speech. Also, reading and writing are severely affected, but cognitive ability remains intact.
- Anomic aphasia – It’s a language disorder where the main symptoms are difficulty in naming objects.
In many cases, these disabilities caused by the damage to Wernicke’s area are not permanent, meaning that language processes can be restored. However, the affected individual will have a hard time fully recovering from the disorder which has affected their ability to speak.
To Sum Up
Wernicke’s area is the brain’s center for the understanding, development, and comprehension of speech and language. Comprehension of speech is a complex process that is processed and regulated in this particular area of the brain.
By processing, distinguishing, and assigning lexical meaning to the sounds we hear, Wernicke’s area aids our fluency and understanding of language.
If Wernicke’s area is damaged or becomes dysfunctional, the memory of words and sounds becomes impaired. This leads to difficulty in the cognitive processes, mainly in speech, but also in learning and memory.
Fun Facts
Did you know?
- Wernicke’s area controls not only spoken language but also the sign language which is used for communication by individuals with hearing problems or deaf people.
- Both of the cerebral cortex areas of the brain dedicated to the understanding and production of speech – Broca’s and Wernicke’s areas – are connected with each other by the arcuate fasciculus.
It’s a bundle of axons that connects the parts of the brain which are relevant to speech and language.
- An individual affected by aphasia can effectively communicate with other people in various creative ways. Some of them include writing or typing sentences and responses.
- Carl Wernicke is the German neurologist who first discovered the area of the brain dedicated to the recognition and production of language. It was later labeled as Wernicke’s area in honor of his work.
Wernicke made this revolutionary discovery in medicine in 1874, by identifying the exact location on the cerebral cortex where speech is regulated and controlled.
- Brodman area 22 extends to both hemispheres of the brain. On the left side, it’s part of Wernicke’s area and aids our understanding of individual words, while on the right side, it helps us distinguish the intensity and pitch of the sound.
- Prosody differs from language to language. Due to this, it creates different strategies for the segmentation of perceived sounds of speech.
- Individuals affected by anomic aphasia have a distinct feeling of having the word at the tip of their tongue, but being unable name the object.
- The temporal areas of our brain are also responsible for monitoring our own speech.
- The size od the gyri in Wernicke’s area influence the fluency of a person. Namely, the larger the gyri, the greater the fluency.
- Prosody helps us determine the emotional tone of the utterance. Depending on the intonation of the following sentence: “Yeah, I liked the song.”, we can conclude whether the speaker really enjoyed the song, or the utterance is said ironically.