Study of Language Presentation 4 (Language and the Brain) PDF

# The Study of Language ## Presentation 4: Language and the Brain ### Outline of the presentation - What we know from the previous classes - Parts of the brain involved in language production/ comprehension - Dichotic listening tests - Speech errors: why are they important? - Aphasia studies - Ot...

# The Study of Language ## Presentation 4: Language and the Brain ### Outline of the presentation - What we know from the previous classes - Parts of the brain involved in language production/ comprehension - Dichotic listening tests - Speech errors: why are they important? - Aphasia studies - Other brain disorders affecting communication - Genie: neurolinguistic findings ### What do we know from the previous classes: - The human brain - lateralized, i.e. we have, in fact, a 'left brain' and a 'right brain', two hemispheres. - Language faculty/ centre(s) which coordinate language and communication - the left hemisphere. - The critical period hypothesis - lateralization of the brain is complete by the time the child reaches the age of puberty (12-13). If the child has not acquired any language by that time, it is impossible afterwards (to be discussed later as well), as shown by cases of Genie and other feral children. ### The two hemispheres - The left hemisphere: largely analytical (language, math, analysing music etc.) - The right hemisphere: more 'artistic'/holistic - Both of them are connected by a bundle of nerves called *the corpus callosum*, transmitting information, stimuli etc. ### Parts of the brain involved in language production/ comprehension - **Neurolinguistics** - connection between language and neurology (studying the brain). - One event (19th cent., the US) that was the first step in locating language production in the brain: a case of a construction worker who had his head injured by a metal rod, which went in his left cheek and out the top of his forehead, and did not display language/communication deficiencies. **Conclusion:** language functions are definitely not located in the front part of the brain. #### The localization view: The belief that specific language functions can be traced back to specific parts of the brain so we can hear a word, comprehend it and then say it. There are four components of the brain considered to relate to language function: - Broca's area - Wernicke's area - The arcuate fasciculus - The motor cortex #### Objects of analysis: - Slips of the tongue and similar mistakes (speech errors) - Linguistic behaviour in brain-damaged patients (e.g. stroke victims) - The actual brain tissue (autopsies) #### Methods: - CT scans, interviews, various means of testing (tasks on language production/ comprehension etc.) - Dichotic listening tests (see next slide) ### Dichotic listening tests - One method of finding out about language processing inside the brain. - The subject has headphones/earphones on and hears two words/ syllables played simultaneously, one goes in through the right ear and another one through the left. - **An example:** Imagine that you are taking such a test and hear cat through the left earphone and da through the right one. Which one will be identified faster (cat or da) and why? - **Most probable answer:** da - **Reason:** It comes through the right ear, *travels* directly to the language faculties located in the left hemishpere. - **In contrast**, the word cat needs to travel longer: left ear → right hemishpere → left hemisphere (via the corpus callosum) = *right ear advantage* - **For dessert. Left or right ear?** linguistically meaningful content, melodies, nonsence syllables, environmental sounds (e.g. dog barking), speech played backward, laughing, coughing. #### Possible answers: - Linguistically meaningful content - right. - Melodies - could be both. - Nonsense syllables - right. - Environmental sounds (e.g. dog barking) - left. - Speech played backward - right. - Laughing - left. - Coughing - left. ### Crucial parts of the brain and what they do Back to the four parts of the brain linked to language function: - Broca's area - Wernicke's area - The arcuate fasciculus - The motor cortex ### Broca's area - **Alternative name:** anterior speech cortex. - **Task:** production of speech. - Mid-19th century: Paul Broca (1824-1880, a French surgeon) found that injury/damage to this region of the brain means extreme difficulty in speech production (slow, laboured speech with a lot of pauses), while language comprehension was unaffected. - **His other findings:** craniometry, anthropology, comparative anatomy, controversies, disputes with Darwin and other scientists. ### Wernicke's area - **Alternative name:** posterior speech cortex. - **Task:** understanding speech. - Mid-19th century: Carl Wernicke (1848-1925, a German surgeon) found that injury/damage to this region of the brain means heavily impaired language comprehension (speech was unaffected and fluent but generally incomprehensible and incoherent, a lot of vacuous phrases, roundabout expressions, no 'essence'). - **His other findings:** the arcuate fasciculus (see later slide), Korsakoff's syndrome (to be discussed later), research on encephalopathy. ### The motor cortex - **Key function:** coordination of the muscles (in general). - One part of the motor cortex located close to Broca's area - the muscles of the articulatory organs (jaw, tongue, larynx, face). - The first studies linking this part of the brain to language production: late 1950s (Penfield and Roberts), *method:* electrical stimulation. ### The arcuate fasciculus - A group of nerve fibres between Broca's area and Wernicke's area. - **Task:** connecting the two areas, language processing (probably prosody and semantics). - Discovered and studied by Carl Wernicke (mid-19th cent.) - Damage to the arcuate fasciculus - problems with transferring information (language input) between Broca's area and Wernicke's area. - Other anomalies - seen in schizophrenic patients with auditory-verbal hallucinations. ### Speech errors - why are they important? Mistakes like slips of the tongue/ slips of the ear - a mine of information about how our brain processes language (also in people with no brain dysfunction/ injury). #### Three most important types: - Tip of the tongue phenomenon - Slip of the tongue - Slip of the ear #### The tip of the tongue phenomenon: We feel that the word we want to utter is 'almost here'/ we 'almost have it' but we just cannot get it right. #### Another name: Malapropisms (based on a fictional character, Mrs Malaprop, who constantly made such mistakes, which produced comic effects). #### A more humorous name: Freudian slips. #### Examples: - We need a few laughs to break the monogamy, a fire distinguisher (in lieu of fire extinguisher), medication (in lieu of meditation). - We test different 'candidates' (i.e. other words) but none of them is the word. - **Interesting fact:** all those 'candidates' or near-misses are similar to the desired word in terms of sound patterns + of similar length - *what does it tell us about how knowledge is organized in the brain?* #### Slip of the tongue: A switch/reversal of (usually initial) sounds in two words in a phrase (e.g. shake a tower in lieu of take a shower) or two whole words in a phrase (e.g. to gap a bridge in lieu of to bridge a gap). #### Another name: Spoonerisms (Reverend Spooner, an English clergyman). #### Interesting fact: All the words produced in this way may be mistakes, but they are phonologically acceptable + pronounceable (!). #### They could point to various stages of articulating words. #### A more humorous name: Tips of the slung. #### Which of these expressions are malapropisms and which are spoonerisms? - Spreading like wildflowers - Leed of spight - Slow and sneet - An expensive pendulum round that woman's neck - Michelangelo painted the Sixteenth chapel - A well-boiled icicle - Good punctuation means not to be late - A wolf in cheap clothing - The monster is just a pigment of my imagination - White Anglo-Saxon prostitute - Prinderella and the Since - Beeping Sleuty - The 1967 virgin of his dissertation - Heft lemisphere #### Answers (malapropisms/spoonerisms) - Spreading like wildflowers - Leed of spight - Slow and sneet - An expensive pendulum round that woman's neck - Michelangelo painted the Sixteenth chapel - A well-boiled icicle - Good punctuation means not to be late - A wolf in cheap clothing - The monster is just a pigment of my imagination - White Anglo-Saxon prostitute - Prinderella and the Since - Beeping Sleuty - The 1967 virgin of his dissertation - Heft lemisphere #### For dessert. Some authentic (!) examples by Rev. Spooner: | Said | Intended... | |---|---| | Fighting a liar | Lighting a fire | | You hissed all my mystery lectures | You missed all my history lectures | | Nosy little cook | Cosy little nook | | A blushing crow | A crushing blow | | Noble tons of soil | Noble sons of toil | | We'll have the hags flung out | We'll have the flags hung out | | Cattle ships and bruisers | Battle ships and cruisers | | You've tasted two worms | You've wasted two terms | | Our shoving leopard | Our loving shpeherd | | A half-warmed fish | A half-formed wish | #### Slips of the ear: More of a misunderstanding - sounds are heard and identified, but we organize them in a different way - **different meanings**. **Intended meaning:** Please bring me a grey tape. **What was heard:** Please bring me a great ape. #### Children's speech / language learners. #### Conclusion: Our brain tries to make sense of any signals it receives. #### Slips of the ear - a few more examples: | Said | Heard as... | |---|---| | Death in Venice | Deaf in Venice | | What are those sticks? | What are those ticks? | | Maybe we could give them an ice bucket | Maybe we could give them a nice bucket | | Kill germs where they grow | Kill germs with eggroll | | An alcoholic | A nalcoholic | | A coke and a Danish dessert | A coconut Danish dessert | | [Polish]: oddawać mu honory po śmierci (to pay our last respects to him after his death) | oddawać muchomory po śmierci (to return poisonous mushrooms after your death) | ### Aphasia studies - **Definition:** 'partial or total loss of the ability to articulate ideas (...) due to brain damage' (from the *National Institute of Health information page*). - Impairment of language function (often accompanied by interrelated communication disorders). - **Causes:** stroke, accidents, injuries. - **Most important types:** - Broca's aphasia = result of damage to Broca's area - Wernicke's aphasia = result of damage to Wernicke's area - Conduction aphasia = result of damage to ......? - **Over to you.** With the following information: - Broca's area is largely responsible for speech production. - Wernicke's area is largely responsible for language comprehension. - The arcuate fasciculus connects there two areas, ...can you guess the symptoms of the three types of aphasia (Broca's, Wernicke's, conduction)…? ### Broca's aphasia - Another name: motor aphasia. - Slow, laboured, effortful speech. - Distortions. - Mostly content words/lexical morphemes (verbs, nouns, adjectives...), few functional words/functional morphemes (e.g. articles), few or no grammatical markers - **agrammatical speech.** - Comprehension is intact. - Most aphasics are painfully aware of their condition. ### Wernicke's aphasia - Huge problems with comprehension. - Speech is fluent but incoherent, no content - **word salad.** - Roundabout/vacuous descriptions, general terms. - Repetitions. - **Anomia** - difficulty finding names, coping strategy: definitions (this thing you use for… in…). - Initially, patients seem not to be aware of their condition. ### Wernicke's aphasia: what do the patients say? - Sometimes I can't find a word, so I kinda talk "around that word": "The thing you put on your hand, it's warm fabric, five fingers, you wear them in winter…." I am aware of doing this; it's weird, but (…) everyone gets "tip of the tongue" syndrome sometimes, so it's relatable. Sometimes I can't figure out how to make a cohesive sentence at all, so I babble random related words while trying to mime what I'm trying to say: "Put…hand…the thing….” I am aware of doing this; it's quite upsetting, because I cannot even convey that I'm having a moment of expressive problems, and folks tend to give me weird looks. It also causes problems when I'm expected to speak, but cannot say anything, and thus am judged for being rude or uncooperative. Sometimes I say related or similar looking/sounding words: "I'm in a lot of paint (pain)", "The hospital (dentist) called for me to book an appointment." Sometimes I'm aware of this (…) and I can immediately correct it. But (…) I come across as though I were drunk or "crazy." Other times I have no idea what I've said until someone responds with an odd look or awkward moment of silence, and I have to ask them to repeat back to me what I said. The worst is when I'm not aware of what I'm saying. "Put the box in the bedroom (laundry room)"; "Set aside Sunday (Tuesday) for a dinner with Frank." I don't sound like I'm mixing up words (…) and I have no idea that what I've actually said is incorrect. This causes a lot of conflict and misunderstandings in my life (eg the box now has to be moved from the bedroom; mixed-up dinner plans), and is quite distressing (*Source:* discussion forums/YouTube comment sections). - It's like your brain is completely sober and sharp and 'normal', but words are drunk and won't cooperate (*Source:* discussion forums/YouTube comment sections). ### Conduction aphasia - Articulation is fine despite occasional mispronunciation. - Speech is fluent, but there are interruptions (pauses, hesitations). - Comprehension is quite good. - Problems with repeating a word after another person. - **Examples of mispronunciation and other mistakes:** snowall, vellitision, ninety-twenty, vaysse, fosh (intended: snowball, television, ninety-five, base, wash) - reversals, switches etc. ### Aphasia - possible prognoses - Is the aphasia diagnosis the end of everything? Is it irreversible? - Neuroplasticity of the brain. - Speech therapy, a lot of systematic speech rehabilitation - repetitions - *reinforcing the connections*. - Singing therapy, or melodic intonation therapy (MIT): singing engages the right part of the brain, but some studies have shown a correspondence between singing and an improved performance in overcoming aphasia - *help in promoting the carryover of language skills to the right side of the brain*. ### Other brain disorders affecting communication - Split-brain patients - Agnosognosia - Korsakoff's syndrome - Capgras's delusion ### Split-brain patients - Studies made on patients who have had their two hemipsheres separated surgically (their corpus callosum was cut) due to epileptic seizures - *living with 'two brains'*. - Patients are e.g. shown pictures visible to their left eye and asked to name the objects they see - they say that they e.g. forgot the name of the object, but are able to draw it with their left hand. - Confabulation (i.e. lying/deceiving): fabricating stories that justify the lack of communication between the hemispheres; here, the patients are not even aware of lying - *coping strategy*. ### Agnosognosia - Patients suffering from this disorder are not aware of the physical diseases that they have and make up stories instead of admitting that they are ill. - A person who is e.g. paralyzed will say that they suffer from arthritis and that stops them from moving; if they are asked to e.g. reach for a sweet (and their arm is paralyzed, so they cannot do it physically), they say that they had to mind their weight, etc. - They are deeply convinced that what they say is true. ### Korsakoff's syndrome - Another discovery made by Carl Wernicke (another name: Wernicke-Korsakoff syndrome). - Short-term amnesia (long-term memory is not affected). - Fabricating stories that replace most recent memories and believing in them to avoid, or save themselves, possible embarrassment or confusion. ### Capgras's delusion - The main symptom: the belief that one's nearest and dearest have been abducted and replaced by imposters. - The affected area of the brain: the component responsible for emotional reactions caused by seeing someone we know/recognize. - As they do recognize their loved ones but don't feel anything on seeing them, they make up stories which they accept and believe in and which justify their confusion. ### Genie: neurolinguistic findings - Very simple syntax (most complex phrase: applejuice buy store). - No left hemisphere language activity/facility. - Language functions (although limited) taken over by the right hemisphere, very strong left ear advantage. - Compensation: nonverbal communication was extermely powerful and persuasive. - When Genie started using speech - some stages observed in children acquiring their first language. ### Sources: - McRaney, David (2011). *You Are not So Smart*. Sheridan: Gotham Books. - Sacks, Oliver (1985). *The Man who Mistook his Wife for a Hat*. New York: Summit Books. - Yule, George (2010). *The Study of Language, Fourth Edition*. Cambridge: Cambridge University Press. - www.fun-with-words.com - https://www.flintrehab.com/melodic-intonation-therapy-aphasia/