W10: Neurolinguistics, neuroimaging, language problems

Question 1

What is phrenology?

Answer 1

Looking at the shape of the head as though indicative of mental processes or character traits (Gall)

Question 2

What does phrenology say about language?

Answer 2

Would suggest that language is localized to a particular brain region that would protrude when using language

Question 3

Is the concept of phrenology correct?

Answer 3

No its not right, but the underlying idea of localization is still valid

Things like vanity, friendship and wisdom is not localised as gall proposed.

Question 4

Are there any sex differences in language lateralization?

Answer 4

Males are more lateralised when it comes to language, being represented in just one hemisphere

Female brains are less lateralised with language - more spread out across the hemispheres

Question 5

Explain language critical periods

Answer 5

The ability to acquire language declines with age

- language input must occur during critical period for development to proceed normally

Question 6

What is evidence towards language critical periods?

Answer 6

Lateralisation of language

Second language acquisition (children learn better - adults struggle)

Children deprived of early language (e.g. genie didn’t learn syntax but hard to disentangle from other problems eg. neglect)

Question 7

What is the subtraction method in brain imaging?

Answer 7

Have the participant carry out one task, then do a variant of that task

Subtract one image from another - you can then identify differences and attribute areas towards function

Question 8

What are some critiques of the subtraction method?

Answer 8

Areas of the brain can be active without being critical

People can be dimly thinking about something else at the same time - you can’t assume they are focussing on just the one task

Question 9

Neuroimaging involves what trade-off?

Answer 9

Temporal (what) vs. spatial (where) accuracy

Question 10

Explain event-related potentials (ERP)

Answer 10

Place electrodes against the scalp to record the electrical activity of the brain

Present a stimulus - measure voltage changes

Question 11

Is there a trade-off in ERP?

Answer 11

Good temporal resolution - you can tell when

But you cant tell where - poor spatial resolution

Question 12

Explain ERP peaks

Answer 12

Labelled in terms of polarity (positive/negative) and latency (ms since stimulus)

Interestingly, a negative peak is above the line and a positive peak is below the line

Question 13

Explain magnetoencephalography (MEG)

Answer 13

Recent method

Measures magnetic activity in the brain
Good temporal and spatial resolution (can tell when and where things happen)

Not done unless it really has to be

Question 14

Why isn’t MEG used very often?

Answer 14

Very difficult and expensive to conduct
Need superconducting devices, extreme cooling and magnetic shielding (need shielding from magnetic activity because want to explore the tiny emissions given off by the brain)

Question 15

Explain computerised axial tomography (CAT)

Answer 15

X-ray images are taken from all angles around the head and are integrated to form a whole picture

Question 16

What are the pros to using CAT scans?

Answer 16

They are non-invasive, are well tolerated and are not as expensive as others

Question 17

What is the temporal/spatial trade-off in a CAT scan?

Answer 17

Alright both temporally and spatially but not great either way

Question 18

Explain positron emission tomography (PET)?

Answer 18

Radioactive glucose is injected into the blood

Participant given task

Detectors around the head measure where the glucose is being used

Produces a 3D model of blood flow in the brain during a task

Question 19

What is the downside to PET?

Answer 19

It is more invasive having injections etc.

Question 20

What have PET scans told us about how we process regular and irregular past tense verbs?

Answer 20

Different parts of the brain lit up for each - meaning we process them in different parts of the brain

Question 21

Explain functional magnetic resonance imaging (fMRI)

Answer 21

Measures the energy released by haemoglobin in the brain areas using the most oxygen

detecting the changes in blood oxygenation and flow that occur in response to neural activity – when a brain area is more active it consumes more oxygen

Question 22

What are the pros of fMRI?

Answer 22

Good spatial resolution, reasonable temporal resolution

More precise than PET

Question 23

fMRI is not as good as….

Answer 23

ERP

Question 24

What have fMRI’s shown us regarding sex differences in language lateralisation?

Answer 24

Were given nonsense word rhyme-judgement task to participants

Activation of the inferior frontal gyrus occurred in:

• The left hemisphere in men
• Both hemispheres in women

Supporting the idea that linguistic organisation differs between male and female brains

Question 25

What is a major disadvantage to male brains being more lateralised?

Answer 25

If injured, men are more likely to be incapacitated

Question 26

Explain transcranial magnetic stimulation (TMS)

Answer 26

Powerful magnets are used to stimulate the cortex - record physical response Reverse of other techniques as you cause brain activity rather than observe it Temporarily disrupts processing of the particular part of the brain to find out what tasks you need the region for

Question 27

What is aphasia?

Answer 27

The loss of ability to speak

Question 28

The study of aphasia has...

Answer 28

helped us to understand the organisation of language in the brain

Question 29

Explain broca's patient

Answer 29

He had lost the ability to speak but was intelligent and could understand language Could only say 'tan' and gesture An autopsy revealed selective damage in LHem and at junction of temporal, frontal and parietal lobes Then went on to study 20 more cases

Question 30

What is broca's aphasia?

Answer 30

Speech is slow, laborious and hesitant, little inotation and articulation problems DEFICIT IN SPEECH PRODUCTION

Question 31

Explain Wernickes patient

Answer 31

Patient with intact speech, but very little language comprehension An autopsy revealed selective damage in LHem rear, parietal/temporal region

Question 32

What is wernickes aphasia?

Answer 32

Fluent but nonsensical speech, adequate syntactic structure, function words intact but problems with content words, normal prosody DEFICIT IN SPEECH COMPREHENSION

Question 33

What is more important than wernickes and brocas area separately?

Answer 33

The connection between them

Question 34

What is pure word deafness?

Answer 34

Lesion disconnects wenickes area (comprehension) and heschl's gyrus (hearing) These patients can hear but the signals cannot get to wernickes area so they cannot understand speech

Question 35

What is conduction aphasia?

Answer 35

Lesion damages the arcuate fasciculus - disconnects brocas and wernickes Speech production is intact and output is well formed, they can understand most of what they hear but they're unable to repeat what they hear

Question 36

What is agrammatism?

Answer 36

Deficit in sentence construction Content words are preserved better than function words Also extends to sentence repetition and the understanding of syntactically complex sentences

Question 37

What is jargon aphasia?

Answer 37

Syntax is intact, but major word finding problems - Paraphasia (substituting content words for others eg pencil for pepper) - neologisms (made up words eg swizl for whistle) They do not realise they are doing this and get frustrated when other people cannot understand them

Question 38

What is anomia?

Answer 38

Impairment in retrieving names of objects Damage to the angular gyrus Lexical-semantic anomia - can name members of some semantic category but not another Phonological anomia: problems retrieving phonological information about word but no problem with word meaning (tip of the tongue)

Question 39

What is Garrett's model of speech production?

Answer 39

Conceptualisation (preverbal message) Thinking of coffee Formulation: concept translated into linguistic form (words, syntax, sounds) Flat white, just one, be polite Execution: detailed phonetic and articulatory planning, articulation = produced speech 'a flat whit please'

Question 40

What is the functional level of Garrett's model?

Answer 40

- Content words are selected - Word meanings are specified - Words assigned to syntactic roles

Question 41

What is the positional level of Garrett's model?

Answer 41

- Function words are selected | - Words are put in correct order

Question 42

How would you describe someone with agrammatism with Garrett's model?

Answer 42

Problems translating between functional and positional levels Can't really get it to the positional level - can't create a frame for the sentence, can't get the function words you need so you can't put the content words together in a sentence

Question 43

How would you describe someone with Jargon aphasia with Garrett's model?

Answer 43

Positional level is fine - affixes etc are correct even if words are wrong so you have correct syntax - words are put in right order Problem is with functional level - finding the right words and assigning them to their role Supporting idea that content words are retrieved independently from syntactic frames and inflections

Question 44

How would you describe someone with anomia with Garrett's model?

Answer 44

The two different kinds of anomia support differences in semantic and phonological processing in the functional level of Garrett's model