Week 5 Spring Language and the Brain PDF

W5. Language and the Brain: Two Types of Aphasia Neurolinguistics is the study of language and the physical brain. To discover where and how the brain processes language, we need to know where the language centers of the brain are a...

W5. Language and the Brain: Two Types of Aphasia Neurolinguistics is the study of language and the physical brain. To discover where and how the brain processes language, we need to know where the language centers of the brain are and how information flows between these areas. Experimental techniques that allow us to see the brain in action play a large role in neurolinguistics, as do studies of patients with language disorders. This lecture will look at where things can go wrong in two regions of the human brain that are thought to be essential for understanding and using language. Remember that human brain is an extremely complex organ, and our knowledge of its inner workings is still very limited. Physical Features of the Brain The brain is divided into the right and left hemispheres. Each is responsible for processing certain kinds of information about our world. Each hemisphere is further divided into four areas of the brain called lobes. The temporal lobe is associated with the perception and recognition of auditory stimuli The frontal lobe is concerned with higher thinking and language production The occipital lobe is associated with many aspects of vision. What is aphasia? Aphasia is a general term used to refer to several types of language impairment Typically, patients with aphasia have difficulty producing and/or comprehending speech It can also affect their ability to read and write There are several different types of aphasia with different symptoms: Alexia = cannot read Agraphi = cannot write Conduction aphasia = the inability to repeat what someone just said Two of the most common are Broca’s aphasia and Wernicke’s aphasia Broca’s aphasia Broca’s aphasia is named after the French scientist, Paul Broca (1824 – 1880) who first related a set of deficits associated with this type of aphasia to localized brain damage. In the 1860s, Broca observed that damage to the left side of the brain resulted in impaired language ability He started conducting his research 1861, after caring for a patient who could only say the word “tan”. Since that time, a number of language disorders have been traced to particular types of brain injuries, helping pin down which regions of the brain are involved in language processing. These conditions, in which patients lose their ability to produce or understand language due to stroke or brain injury, are known as aphasias. Class activity Watch the following video of a patient with Broca’s aphasia https://www.youtube.com/watch?v=JWC-cVQmEmY What aspects of speech seem to be difficult for him? What does he have no difficulty with?  What we can say about Broca’s aphasia… Patients have difficulty producing grammatical sentences and their speech is limited mainly to short utterances of a few words Producing the right sounds or finding the right words is often a laborious process This is important because it tells us that Broca’s area is involved in language production generally (not only speech) Individuals with Broca’s aphasia have trouble speaking fluently but their comprehension can be relatively preserved. This type of aphasia is also known as non-fluent or expressive aphasia What we can say about Broca’s aphasia… A person with Broca’s aphasia may understand speech relatively well, particularly when the grammatical structure of the spoken language is simple However, they may have harder times understanding sentences with more complex grammatical constructions For example, they may find sentence (a) easy to understand, but sentence (b) may pose a challenge when interpreting the meaning of who gave the balloons to whom (a) “Mary gave John balloons” (b) “The balloons were given to John by Mary”  Stephanie and Brent: The Effect of Broca’s Aphasia on a Family Listen to the video and answer the questions: https://youtu.be/gSJ0Tfsbjjo?si=NHYMF3hNYMcyE67V (9:22) 1.How long since Brent had a Stroke? 2. Why did brent want to come to the Centre? 3. What kind of communication is difficult for Brent? 4. How long is the course he is on? 5. What other ways can brent communicate if speaking is difficult? 6. What is one of Brent’s goals? 7. What advice does Stephanie give to other carers? 8. Finally: what is brent’s last piece of advice?  Wernicke’s aphasia Wernicke’s aphasia and Wernicke’s area are named after the German neurologist, Carl Wernicke. Wernicke first related this specific type of speech deficit to damage in a left posterior temporal area of the brain Impaired comprehension: deficits in understanding (receptive) written and spoken language. This is because Wernicke's area is responsible for assigning meaning to the language that is heard, so if it is damaged, the brain cannot comprehend the information that is being received. Neologism is a latin word meaning "new words". Patients with this condition make up their own words and think people understand them. In this form of aphasia, the ability to grasp the meaning of words and sentences is impaired, while the ability to produce connected speech is not very affected Therefore, Wernicke’s aphasia is also referred to as fluent aphasia or receptive aphasia  Wernicke’s aphasia People with Wernicke’s aphasia can produce many words and they often speak very fluently with normal intonation However, often what they say (or write) doesn’t make a lot of sense and their sentences may contain irrelevant or even non-existent words They may fail to realize that they are using the wrong words or using a non- existent word and often they are not fully aware that what they say doesn’t make sense Damage to Wernicke’s area also affects writing This means that Wernicke’s area is involved in the comprehension of language generally (not only spoken language)  Wernicke’s aphasia Watch the following video of a patient with Wernicke’s aphasia How would you describe his speech? What aspects of speech seem to be difficult for him? What does he have no difficulty with? https://www.youtube.com/watch?v=3oef68YabD0 Class activity: Listen to the video and write down the answers in your worksheet. Then go to Week 5 Discussions and post the answers. https://youtu.be/-GsVhbmecJA?si=1-dT-3quOxwqqMLF What causes aphasia? Stroke illness trauma What is paraphasia? House/horse (sim) - switching related words dog/cat (related) What are the 2 types of aphasia? Fluent –words lack meaning /non fluent or expressive good comp but long hesitation The right hemisphere controls language. True or false. - false Dr. Broca’s first patient could only say one word – what was it? tan What does Broca’s area help with in normal people? Name objects/ coordinate muscles for speech What does Wernicke’s area help with in normal people? Meaning to speech sounds How many new cases of aphasia are reported in the USA every year? What is PPA? Primary progressive aphasia (form of dementia) – lang first to go Aphasia affects intelligence. True or False. Indicate, by putting an “X” on the appropriate lines, which symptoms are found in patients with each type of aphasia. Difficulty with difficulty with language production understanding language Broca’s aphasia __________ __________ Wernicke’s aphasia __________ __________ Conduction aphasia __________ __________ Alexia __________ __________ Agraphi __________ __________