Neurolinguistics: Language and the brain Psycholinguistics Neurolinguistics: Language and the brain

The case of Phineas Gage He was a railroad construction foreman in 1848. An iron rod passed through his head in an explosives accident. He survived, and was back at work within a few days. His language ability was unaffected Major personality problems ensued He probably did not join a circus: Fromkin is wrong!

Modularity Before Gage: the brain just a big mass? Now, evidence that different brain parts have different functions Early evidence was from autopsies Now, of course, we can use MRI and other technologies

Lateralization The brain is made up of two hemispheres Motor control Left and right Motor control Right hemisphere controls left side of body… Left hemisphere dominates in Language and cognitive processing Right hemisphere dominates in Non-verbal processing, eg spatial relations Handedness research (easy explanation here)

Left hemisphere Broca’s area Wernicke’s area (1870s) Motor cortex Damage here Affects speech production Wernicke’s area (1870s) Injury here leads to comprehension difficulties Motor cortex Articulator controls close to Broca’s area Arcuate fasciculus Discovered by Wernicke Nerve bundle linking Broca’s and Wernicke’s areas

Dichotic listening The right ear advantage The sound played through the right ear reaches Wernicke’s area more directly So, pa will more likely be the sound perceived

Aphasia Impairment of language function caused by a stroke or head injuries Broca’s aphasia: often Slow, distorted speech Agrammatic Mostly lexical words Function words wrongly used, or not used “I eggs and eat and drink coffee breakfast”

Wernicke’s aphasia Can include anomia (difficulty finding the right word) Related to the “tip of the tongue” phenomenon, which we all sometimes experience Often difficult for the hearer to understand Even though the speech can be very fluent “I can’t talk all of the things I do, and part of the part I can go all right, but I can’t tell from the other people”

Slips of the tongue TOT Malapropisms (choosing the wrong word) It seems words can be accessed in the mental lexicon by phonological, semantic or even spelling (at least in English!) You can think of a word with similar meaning, or similar sound… but not the right word! Malapropisms (choosing the wrong word) Good punctuation means not to be late. He's a wolf in cheap clothing.

Spoonerisms (Tips of the slongue) You have tasted three whole worms You will leave Oxford by the town drain You have hissed all my mystery lectures Oscar Wilde (deliberate!) Work is the curse of the drinking classes All sorts of similar stuff here (will not be in the exam!)

Language acquisition: the critical period Language cannot be effectively learned after brain lateralization is complete This may be around puberty Some (eg Fromkin) say that Genie’s story proves the CP hypothesis. Yule make the opposite claim Genie had zero exposure to language until she was 13, but she did acquire some language She learnt words, but very limited syntax Dichotic experiments showed that she had no left-hemisphere language facility It is possible to use the right hemisphere for restricted language purposes.