Brain and the speech ( bronca's areas )

brain and speech

1. ANATOMY PRESENTATION  PRESENTERS: IRM FATIMA FIZA SHAMSHER MARYAM NOOR FAISAL MUKHTAR 

2. Speech and the brain

3. LATERALIZATION Brain is divided into two hemispheres; a left hemisphere and a right hemisphere. This is called lateralization.

4. LATERALIZATION In human beings, the left hemisphere that usually contains the specialized language areas. This holds true for 97% of right-handed people, about 19% of left-handed people have their language areas in right hemisphere and as many as 68% of them have some language abilities in both left and right hemispheres.

5. LATERALIZATION Lateralization was first discovered in the 1800's by physicians such as Paul Broca and Carl Wernicke These physicians found damage to particular areas of the brain now named after them, and these areas were consistently on the left hemisphere.

6. LATERALIZATION Most recently, researchers have taken advantage of the huge advances made in brain imaging. In particular, the PET scan. Since active areas of the brain use more energy, and therefore more glucose, they release more radiation, which the computer translates into "warmer" colours such as yellow and red.  Areas that are less active are shown with "cooler" colours such as green and blue. Certain areas of left hemisphere were more active while people were engaged in linguistic activities.

7. LATERALIZATION

8. Introduction to Broca's and Wernicke's Areas

9. Broca's Area The first language area within the left hemisphere to be discovered is called Broca's Area, after Paul Broca.

10. Broca's Area Broca was a French neurologist who had a patient with severe language problems. He could understand the speech of others with little difficulty, but only word he could produce was "tan". Because of this, Broca gave the patient the pseudonym "Tan". After the patient died, Broca performed an autopsy and discovered that an area of the frontal lobe, just ahead of the motor cortex controlling the mouth, had been seriously damaged.

11. Broca's Area Physicians called the inability to speak aphasia, and the inability to produce speech was therefore called Broca's aphasia, or expressive aphasia. Sarah Scott-- Broca's aphasia Sarah Scott—3 years later Someone with this has little problem understanding speech.  But when trying to speak themselves they are capable only of slow, laborious, often slurred sequences of words

12. LOCATION OF BROCA'S AREAS Broca’s area, crucial for language production and speech control, is primarily associated with  Brodmann Area  44 and 45, located in the left hemisphere’s frontal lobe. These regions play a central role in speech generation, language processing, and syntactical aspects of communication. Specifically, this area is considered part of a region called the inferior frontal gyrus, a gyrus is a ridge on the surface of the brain’s cortex. Some researchers believe that Broca’s makes up the entire inferior frontal gyrus, while others consider it to make up a portion of this region or expand slightly outside the inferior frontal gyrus.

13. FUNCTIONS OF BROCA'S AREAS If an individual is presenting difficulties with formulating speech and written word, has repetitive speech, or speaks in non-coherent sentences, we now can attribute damage to Broca’s area as a possible reason why these symptoms are being experienced. For instance, it has been suggested that language differences in those with Autism may correlate to differences in Broca’s area (Bauman & Kemper, 2005). The precise importance of Broca’s area in the production of language is still up for debate. Evidence usually implies that damage to this area can impair language production, but there is still some uncertainty over what specific language function is lost as a result of damage. It has been suggested that Broca’s area may play a role in the motor movements necessary for speech production, whilst others have suggested that Broca’s area may be involved with verbal working memory and grammar.

14. Wernicke’s area. Connections To Other Brain Areas .  Wernicke’s area  is located proximate to Broca’s area, within the upper temporal lobe. Whilst Broca’s area has an important role in the production of speech, Wernicke’s area is important for the comprehension of language. People with damage to Broca’s area may have difficulty formulating words and written language, whilst individuals who have damage to Wernicke’s area may not have difficulty producing language but may have difficulty understanding language. The majority of the time, people with damaged Wernicke’s area will often speak fluently, in comparison to damage to Broca’s area, where language is non-fluent or broken up. These two areas are close in proximity, typically in the left hemisphere of the brain, and are connected to each other via a neuronal tract called the arcuate fasciculus.

15. ARCUATE FASCICULUS: The arcuate fasciculus is a  white matter  bundle that contains both long and short fibers , which are used to connect the  frontal, parietal, and temporal lobes . This tract, therefore, acts as a pathway from Broca’s area in the frontal lobes and Wernicke’s area in the temporal lobes. The arcuate fasciculus has a role in syntax, which is a set of rules by which we order words within language. It is believed that Wernicke’s area comprehends language and chooses the correct words to use. This is sent through the arcuate fasciculus to arrive at Broca’s area to be articulated before language is produced.

16. REGIONS OF BROCA'S AREAS Broca's area is a region in the frontal lobe of the brain, typically located in the left hemisphere. It plays a crucial role in language processing, specifically in the production of speech and language comprehension. The area itself encompasses a few specific regions, including: Pars triangularis : This is one of the portions of the inferior frontal gyrus and is involved in the production of language, particularly in forming grammatically correct sentences. Pars opercularis : This neighboring region is also part of the inferior frontal gyrus and is involved in the motor planning of speech, controlling the movements necessary for vocalization. Pars orbitalis: This part of Broca's area is involved in semantic processing and language comprehension. It's important to note that while these specific regions within Broca's area have distinct functions, they all work together in the complex process of language production and comprehension. Damage to Broca's area can result in a condition known as Broca's aphasia, characterized by difficulty in forming grammatically correct sentences and expressing language fluently.

17. DAMAGE TO BROCA'S AREAS CAN LEAD TO; Damage to Broca's area, a small region located in the frontal lobe, can lead to a speech disorder known as Broca's aphasia or expressive aphasia. Individuals with Broca's aphasia have difficulty forming words and producing speech but do not struggle with comprehension. Thus, patients often feel that they know what they wish to say but are unable to produce the words. That is, they are unable to translate their mental images and representations to words.