Language & Brain: Neurolinguistics PDF

LANGUAGE & BRAIN PART 1: NEUROLINGUISTICS Assoc. Prof. Dr AnealkaAziz Hussin Akademi Pengajian Bahasa, UiTM 1 LEARNING OUTCOMES At the end of the module, students should be able to: 1. Explain the parts of the brain that involves in language. 2. Ex...

LANGUAGE & BRAIN PART 1: NEUROLINGUISTICS Assoc. Prof. Dr AnealkaAziz Hussin Akademi Pengajian Bahasa, UiTM 1 LEARNING OUTCOMES At the end of the module, students should be able to: 1. Explain the parts of the brain that involves in language. 2. Explain the different types of aphasia. 3. Explain language and brain development in young children. 2  NEUROLINGUISTICS A study of the relationship between language and different aspects of the brain.  THE HUMAN BRAIN The brain is the most complex organ of the body. The surface of the brain is the cortex, often called grey matter, consisting of 100 billions neurons (nerve cells) and even more glial cells (which support and protect the neurons). The cortex is the decision making organ of the body. It receives messages from all of the sensory organs. It initiates all voluntary and involuntary actions. It is the storehouse of our memories. It is the organ that most distinguishes humans from other animals. THE HUMAN BRAIN The brain is composed of a right and a left cerebral hemisphere, joined by the corpus callosum. It allows the two hemispheres of the brain to communicate with each other. The left hemisphere controls the right side of the body, and the right hemisphere controls the left side. Example: If you point with your right hand, the left hemisphere is responsible for your action. This is referred to as contralateral brain function.  Which areas of the brain are responsible for human linguistic abilities? Establishing the location of language in the brain was an early challenge. In the second half of the 19th century, significant scientific advances were made in localising language in the brain based on the study of people with aphasia. Let’s watch the video: https://www.youtube.com/watch?v=fl RamGBSoP4 https://www.youtube.com/watch?v=kR7_oMSUBFE Phineas P. Gage (1823–1860) Phineas P. Gage (1823–1860) was an American railroad construction foreman remembered for his improbable survival of an accident in which a large iron rod was driven completely through his head, destroying much of his brain's left frontal lobe. The injury affected his personality and behavior over the remaining 12 years of his life‍ - that friends saw him as "no longer Gage."  LOCALIZATION OF LANGUAGE IN THE BRAIN The study of acquired aphasia has been an important area of research in understanding the relationship between the brain and language. Aphasia is the neurological term for any language disorder that results from brain damage caused by disease or trauma. In 1860s, the French surgeon Paul Broca proposed that language is localised in the left hemisphere of the brain, and more specifically in the front part, which is now called Broca’s area. A decade later, Carl Wernicke, a German neurologist, described another variety of aphasia in the areas of the left temporal lobe, now known as Wernicke’s area. LANGUAGE AREAS IN THE BRAIN Brocha’s Area is related to the speech production. Wernike’s Area is related to the comprehension of speech. Motor Cortex controls movement of the muscles. Arcuate Fasciculus is a bundle of nerves that connects Wernike and Broca’s areas.  Dichotic Listening Test An experiment to show how the left hemisphere is dominant for syllables and word processing. This technique uses the generally established fact that anything experienced on the right-hand side of the body is processed in the left hemisphere, and anything on the left side is processed in the right hemisphere. A basic assumption would be that a signal coming in the right ear will go to the left hemisphere and a signal coming in the left ear will go to the right hemisphere.  Dichotic Listening Test A subject sits with a set of earphones on and is given two different sound signals I want L R The cat simultaneously, one through milk. is each earphone. black. For example “The cat is black” on the right ear and “I want milk” on the left ear. Left Right When asked to say what was Ear Ear heard, the subject more often correctly identifies the sound that came via the right ear.: “The cat is black”. Watch the Video: https://www.youtube.com/watch?v=-GsVhbmecJA  APHASIA It is impairment of language function due to localized brain damage that leads to difficulty in understanding and / or producing linguistics forms. Most aphasics do not show total language loss. Causes: Stroke, traumatic head injury Effects: Reduce ability to use the language (understanding and producing) Types of aphasia: Brocha’s Aphasia - injuries to Broca’s area Wernicke’s Aphasia- injuries to Wernicke’s area Conduction Aphasia – injuries to the Arcuate Fasciculus  BROCHA’S APHASIA Broca’s aphasia is named after the French scientist, Paul Broca, who first related a set of deficits associated with this type of aphasia to localized brain damage in 1861. Broca’s aphasia is also known as expressive aphasia. It is a disorder that affects a person’s speech production, particularly his ability to form sentences with the rules of syntax. It is characterised by laboured speech and certain kinds of word-finding difficulties.  CHARACTERISTICS OF BROCHA’S APHASIA It is related to speech production. Speech comprehension is better than production. Produce agrammatic speech. There will be a substantial reduction of the amount of speech especially functional (lacks articles, prepositions, pronouns, auxiliary verbs) and omission of inflectional morphemes. Telegraphic Speech Distorted articulation Slow and effortful speech Watch the Video: https://www.youtube.com/watch?v=z486yEWuTLE  EXAMPLES OF BROCHA’S APHASIA Agramatic Speech Production (Akmajian et al. 2001: p. 543) Examiner: Tell me, what did you do be fore you retired? Aphasic: Uh, uh, uh, pub, par, partender, no. Examiner: Carpenter? Aphasic: (Nodding to signal yes) Carpenter, tuh, tuh, twenty year. Telegraphic speech ‘wife‍come‍hospital’‍(‘my‍wife‍came‍to‍the‍hospital’)‍ ‘cup‍me’‍(‘I‍want‍the‍cup’) Distorted Articulation Examiner: Describe this picture. Patient: kid … kk … can … cookie … caandy …well I don’t know but it’s writ … easy does it … slam … early … fall … men … many … no … girl. Dishes … soap … water … … water … falling pah t hat’s all … dish … that’s all. Cookies … can … candy … cookies cookies … he … down … That’s all. Girl … slipping water … water … and it hurts … much to do. Her … clean up. Dishes … up there … I think that’s doing it. WERNICKE’S APHASIA This condition was first described by German neurologist Carl Wernicke in 1874 who first related this specific type of speech deficit to a damage in a left posterior temporal area of the brain. Wernicke’s aphasia, which is also known as fluent or receptive aphasia, is characterized by impaired language comprehension. CHARACTERISTICS OF WERNICKE’S APHASIA Patients with Wernicke's aphasia speak with normal fluency and prosody (intonation) and follow grammatical rules with normal sentence structure. They can produce fluent speech but often difficult to make sense of. They also do not recognize the errors that they are making. Patients with Wernicke’s aphasia may experience:  CHARACTERISTICS OF WERNICKE’S APHASIA String words together to make sentences that don’t make sense patient described a fork as “a need for a schedule” and another, when asked about his poor vision, replied, “My wires don’t hire right.” Have difficulties in naming everyday objects calling a fork as a ‘gleeble’ calling a pencil as a ‘wiltee’ Use circumlocutions (Meaning expressed in roundabout way) A patient attempting to describe what she had had for breakfast that morning: Patient: This morning for – that meal – the first thing this morning – what I ate – I dined on – chickens, but little – and pig – pork – hen fruit and some bacon, I guess. (Brookshire, 2003: 156) Often producing jargon and nonsense words The only thing that I can say again is madder or modder fish sudden fishing sewed into the accident to miss in the purdles.  CONDUCTION APHASIA Conduction aphasia (associative aphasia) is a language disorder due to a damage to the arcuate fasciculus (a bundle of nerve fibers that connect Wernicke’s and Brocha’s area). A person with conduction aphasia can usually read, write, speak, and understand spoken messages. However, he may be unable to repeat words, phrases, or sentences. A person with mild conduction aphasia might be able to repeat words and short phrases but have difficulty with long or complex sentences. Someone with severe conduction aphasia might be unable to repeat short phrases or even single words. People with conduction aphasia are typically aware of their errors, but have a hard time correcting them. Conduction aphasia is considered a mild form of aphasia and is relatively rare. Watch the video https://www.youtube.com/watch?v=G94TvTvjeeU  ANOMIC APHASIA Anomic aphasia is a mild form of aphasia in which the individual has difficulty with word-finding, or naming items. In anomic aphasia, speech is typically fluent and produced with seeming ease. However, the individual might have trouble retrieving specific words, especially nouns and verbs. A person with anomic aphasia will typically speak in complete, grammatically correct sentences. However, they might use vague words like “thing” or describe an item that they cannot name. For instance, someone who cannot think of the word “apple” might say, “I ate a red, round fruit for lunch.” LANGUAGE & BRAIN DEVELOPMENT  Left Hemisphere Lateralization for Language in Young Children Lateralisation of language to the left hemisphere is a process that begins very early in life. Many studies show that infants as early as one week old show greater electrical response in the left hemisphere to language and in the right hemisphere to music, similar to adults.  Left Hemisphere Lateralization for Language in Young Children In a very intriguing study, researchers videotaped smiling babies and babbling babies (producing syllabic sequences like mamama or gugugu) between the ages of five and twelve months. The videotapes showed that when the babies were smiling their mouths were opened wider on the left side (the side controlled by the right hemisphere) whereas when they babbled the right side of their mouths (controlled by the left hemisphere) were opened wider, indicating greater left hemisphere involvement for language even during the babbling period  Brain Plasticity There is also evidence of considerable plasticity (flexibility) in the system during the early stages of language development. This means that under certain circumstances, the right hemisphere can take over many of the language functions that would normally reside in the left hemisphere. Children who undergo a left hemispherectomy (one hemisphere of the brain is surgically removed) experience an initial period of aphasia, but in certain cases may reacquire a linguistic system like that of normal children. In adults, however, surgical remove of the left hemisphere inevitably results in severe loss of language function, where those who have had their right hemispheres removed generally retain their language abilities. The plasticity of the brain decreases with age and with the increasing specialisation of the different hemispheres and regions of the brain.  The Critical Period During childhood, there is a period when the human brain is most ready to receive input and learn a particular language. This is sometimes called the “sensitive period” for language acquisition but is more generally known as the critical period and lasts from birth until puberty. Genie Wiley If a child does not acquire language during this period, for any one of a number of reasons, then he or she will find it almost impossible to learn language later on.  Genie Wiley In 1970, a girl who became known as “Genie” was admitted to a children’s hospital in Los Angeles. She was thirteen years old and had spent most of her life tied to a chair in a small closed room. Her father was intolerant of any kind of noise and had beaten her whenever she made a sound as a child. There had been no radio or television, and Genie’s only other human contact was with her mother who was forbidden to spend more than a few minutes with the child to feed her. Genie had spent her whole life in a state of physical, sensory, social and emotional deprivation. As might be expected, Genie was unable to use language when she was first brought into care. However, within a short period of time, she began to respond to the speech of others, to try to imitate sounds and to communicate. Her syntax remained very simple. The fact that she went on to develop some speaking ability and understand a fairly large number of English words provides some evidence against the notion that language cannot be acquired at all after the critical period. Yet her diminished capacity to develop grammatically complex speech does seem to support the idea that part of the left hemisphere of the brain is open to accept a language program during childhood and, if no program is provided, as in Genie’s case, then the facility is closed down. In Genie’s case, tests demonstrated that she had no left hemisphere language facility. So, how was she able to learn any part of language, even in a limited way? Those same tests appeared to indicate that Genie was using the right hemisphere of her brain for language functions. In dichotic listening tests, she showed a very strong left ear advantage for verbal as well as non-verbal signals. The finding raises the possibility that our capacity for language is not limited to only one or two specific areas, but is based on more complex connections extending throughout the whole brain. When Genie was beginning to use speech, it was noted that she went through some of the same early “stages” found in normal child language acquisition.  Dissociations of Language and Cognition Is the language faculty a separate cognitive system or derivative of more general cognitive mechanisms? There are numerous cases of intellectually handicapped individuals who, despite their disabilities in certain spheres, show remarkable talents in others. Such people are referred to as savants. For example, Christopher has a nonverbal IQ between 60 to 70. He lives in an institution as he is unable to take care of himself or carry out daily routines like buttoning his own shirt. However, his linguistic competence is as rich and as sophisticated as that of any native speaker. When given written texts in fifteen to twenty languages like Danish, French, Portuguese, Hindi, Turkish and Welsh, he translates them quickly, with few errors, into English. He learned these languages from speakers who used them in his presence, or from grammar books. His situation strongly suggests that his linguistic ability is independent of his general intellectual ability.  Savant Syndrome Alonzo Clemons, acquired savant sculptor Anthony Cicoria, acquired savant pianist and medical doctor Daniel Tammet, author and polyglot Derek Amato, composer and pianist Derek Paravicini, blind musical prodigy and pianist Savant syndrome is a Kim Peek, "megasavant" condition in which someone Leslie Lemke, musician with significant mental Matt Savage, musician disabilities demonstrates Orlando Serrell, acquired savant certain abilities far in Stephen Wiltshire, architectural artist excess of average. The skills Temple Grandin,professor of animal science at which savants excel are Tom Wiggins, blind American pianist and composer generally related to memory. Tommy McHugh, artist and poet This may include rapid Fictional cases calculation, artistic ability, Raymond Babbitt, autistic savant in the 1988 map making, or musical film Rain Man (inspired by Kim Peek) ability. Park Shi-on, autistic savant in the 2013 South Korean medical drama Good Doctor Shaun Murphy, autistic savant in the 2017 U.S. medical drama The Good Doctor Kazan, autistic savant in the 1997 film Cube  Dissociations of Language and Cognition There are also individuals who show the opposite profile such as children with Specific Language Impairment (SLI). Children with SLI do not have brain lesions, but they nevertheless have difficulties acquiring language or are much slower than the average child. They show no other cognitive deficits, they are not autistic or intellectually impaired, and they have no perceptual problems. Only their linguistic ability is affected, and often only very specific aspects of grammar are impaired. Cases of dissociations discussed earlier show that language may be impaired while general intelligence remains intact, supporting the view of a grammatical faculty that is separate from other cognitive systems. THANK YOU [email protected]