PhD MD MBBS Faculty of Medicine Al Maarefa Colleges of Science & Technology Faculty of Medicine Al Maarefa Colleges of Science & Technology Lecture – 12: Speech Nervous System Physiology By Dr. SHAHAB SHAIKH PhD MD MBBS

SPEECH 2 Language is one of the fundamental bases of human intelligence and a key part of human culture. it is all about assigning thing, remember it, then use It”: (express it) : vocally or writing or sign language

Speech Centers: –Broca’s area motor speech area –Wernicke’s area sensory speech area Both connected by Arcuate Fasciculus. Both areas also interact with association areas. 3 SPEECH_ understand func of center is the core of this lec

Explanation of the prev. slide that will summary slide #9+10 so no need to study them In Broca’s : it will memories sequence of muscles contraction required to produce specific sound in order to pronounce specific word. Like how do u move ur tongue when pronouncing the word : Appel In Wernicke’s : In association cortex, Wernicke’s connect auditory to visual to sensory area to understand the language there, so language understood then response.. The response also happen in Wernicke’s, then send the info back to broca’s by Arcuate Fasciculus. 4

Broca’s area It is for Articulation( produce sound, actual speak) – Word formation- memory for words 5 SPEECH

Wernicke’s area It is concerned with language comprehension (understanding). It plays important role in understanding of both spoken and written messages. 6 SPEECH

Arcuate Fasciculus Is a axon pathway between Wernicke’s area and Broca’s area 7 SPEECH Higher-Order Association Cortex Wernicke’s area has connections with various association areas in … Left Frontal Left Temporal Left Parietal Are involved with mediating between concepts and language Just know that it Receives info from every where of brain

8 SPEECH Same as slide #4 but in a pic

PATHWAY FOR HEARING & SPEAKING Steps are: 1.Reception in the primary auditory cortex area of sound signals. 2.Interpretation of words in Wernicke's area. 3.Determination of thoughts in words to be spoken in Wernicke’s area. 4.Transmission of signals from Wernicke’s area to Broca’s area by Arcuate fasciculus. 5.Word formation in Broca’s area. 6.Transmission of signals to motor cortex to control the speech muscles. 9 Nothing here

PATHWAY FOR READING & THEN SPEAKING Steps are: 1.Reading the words – reception in primary visual area. 2.Information passes through angular gyrus region and reaches Wernicke's area. 3.Interpretation of words in Wernicke's area. 4.Determination of thoughts in words to be spoken in Wernicke’s area. 5.Transmission of signals from Wernicke’s area to Broca’s area by Arcuate fasciculus. 6.Word formation in Broca’s area. 7.Transmission of signals to motor cortex to control the speech muscles. 10 Nothing here

SPEECH Lateralization: Speech area are located in one sphere (on one side), usually the dominant hemisphere. Left hemisphere is dominant for fine movements in most Right handed people. Also in many Left handed people. Left hemisphere is therefore called DOMINANT SPHERE. 90% of left handed people have left cerebral hemisphere as dominant also. Y the left hemisphere is dominant in the majority ? –Cus left control the analysis than the Rt. Which is considered with creativity and music 11

SPEECH the Right hemisphere does have its role in speech. also appears to be involved in organizing a narrative—selecting and assembling the elements of what we want to say. The right hemisphere is involved in the expression and recognition of emotion in the tone of voice. Body language, add expression,tone of voice will be on Rt. Hemisphere narrative—selecting: arrange ideas in ur mind when speaking 12

SPEECH DISORDERS Damage to Brocas’s area: (motor aphasia) It results in failure of word formation, but patient can understand the spoken and written words. These people know what they want to say, but can not express themselves. lesions in and around Broca’s area: agrammatism, anomia, and articulation difficulties. Agrammatism= grammatically wrong words Anomia: can’t remember name of specific thing, but can describe it : like a red pen, he can describe it but can’t say the exact word: “Red pen” 13

Damage to Wernicke’s area: (sensory aphasia) These patients can not understand the words they hear or see. Lang comprehension is failing, can’t respond what they say is full of jargon and neologisms that make little sense. jargon : complicated words neologisms : creating new words Ask a Q, not related answers = how’s the weather?, I am fine 14 SPEECH DISORDERS

Anomic aphasia (anomia): Inability to recall name of thing, describe it but don’t remember the exact name,- red pen ex…. is a type of aphasia characterized by problems recalling words, names, and numbers.. Damage to angular gyrus near to Wernicke’s area 15 SPEECH DISORDERS

Conduction Aphasia: Patients may be able to understand speech as well as produce meaningful speech, but have difficulty repeating a spoken sentence. Often associated with damage to the Arcuate Fasciculus, which connects Wernicke’s area with frontal pre-motor structures. Speak but slow, and difficulty, especially when asked to repeat exact sentence, the analysis happens in Wernicke’s but can’t go to Broca’s to be transformed into action SPEECH DISORDERS

Global Aphasia - Damage occurs to both broca’s area and Wernicke's area. -Patient can not understand or speak. -Damage in dominant hemispheres 17 SPEECH DISORDERS

Remember it all Inability to speak

Speech Disorders of Articulation (Dysarthria) Damage speaking mechanism Cerebellar lesions causes dysarthria, speech is with increased word length. it is called scanning speech. Dysarthria in happens in Parkinsonism (basal ganglia) –Speech is monotonous, slurring dysarthria 19 SPEECH DISORDERS

Dysphonia: In Dysphonia, sound is not pronounced properly. Dysphonia is usually due to laryngeal problem. Sound change in laryngeal (sore thraot), nasal problems 20 SPEECH DISORDERS

STAMMERING SPEECH: It is a speech disorder, where person prolongs the word usually at vowels (a,e,i,o,u). e.g. To-to-to-to-morrow Mmmmmmm ilk Commonly occurs by age of 2 ½ to 3 ½ years. 21 SPEECH DISORDERS

DYSLEXIA Dyslexia is difficulty in learning due to auditory reception (word deafness) or visual reception (word blindness). It is developmental problem where connection between visual and speech area of cortex is faulty – “faulty wiring”. In dyslexia, there is no intellectual problem. 22

In the next 2 slides اقروا الكلام اللي بالسلايدين. بس الزبدة if a damage occurs to the dominant hemisphere, let’s say left. one … below 2 years and up to 10 yrs. : Child can learn how to speak cus the rt. Hemisphere will work– can be re-established due to plasticity : need of that area Above 10 years : –Let’s say pt. got Stroke for example, there will be loss in speech, can’t speak for their life, cus it will be very difficult to train the 2nd hemisphere to take the role of the damaged dominant one 23

Speech center is found in one hemisphere i.e. left side. But if a child below 2 years has damage to left cerebral hemisphere then language function are transferred to right hemisphere with no delay in language development. This is due to plasticity or remodeling of brain in response to varying demands. It is due to formation of new neural pathways or connections. 24 SPEECH DISORDERS

Up to the age of 10 years, if damage occurs to left hemisphere, language activity can be re- established in the right hemisphere after a temporary period of loss. After 10 years, there may be permanent loss of speech as regions of brain involved in spoken and understanding speech are permanently assigned before 13 to 15 years. 25 SPEECH DISORDERS