Introduction to linguistics

2014-04-22

Lecture 10: Psycholinguistics

Sources

• Yule, 2006. The study of language. CUP.

– Chapter 13: Language and the brain.

• Fromkin, Victoria, Robert Rodman, Nina

Hyams. 2003. An introduction to language.

– Chapter 2: Brain and language.

Neurolinguistics

• Neurolinguistics

– the study of the

relationship between the brain and language:

– speech, hearing, reading, writing and nonverbal

communication.

– Studies the way language is processed in the

brain,

– especially the processing of spoken language

when certain areas of the brain are damaged.

• N. is an interdisciplinary study.

Subfield

Description

Research questions

Phonetics

The study of speech
sounds

How the brain extracts speech
sounds from an acoustic signal;
how the brain separate speech
sounds from background noise.

Phonology

The study of how
sounds are organized
in a lg

How the phonological system of a lg
is represented in the brain.

Morphology

The study of how
words are structured
and stored

How the brain stores and accesses
words that a person knows.

Syntax

The study of how
sentences are
constructed

How the brain combines words into
phrases and sentences; how
structural and semantic information
is used in understanding sentences

Semantics

The sudy of how
meaning is encoded in
lg

Language and the brain

• The human brain is divided into

a lower section (

the brain

stem

) and a higher section (

the

cerebrum

• The

brain stem

controls such

critical functions as breathing,

heartbeats and consciousness.

• The

cerebrum

integrates us

with the environment.

Language is likely to be

organized here.

– Divided into 2 parts: the left and

right hemispheres, linked by a

series of bridges.

The hemispheres

• Each hemisphere controls the opposite side of

the body,

– but they do not function in the same way.

• Certain functions tend to be dominated by

one hemisphere.

• The specialization of brain functions by area is

called

lateralization

2014-04-22

Evidence

• The Wada test

(developed by Wada in the

1940s) – a barbiturate is introduced into one
of the arteries; the drug reaches one
hemisphere and shuts it down; then it is
possible to evaluate the working of the other
hemisphere.

– The patient is given a number of language tests to

see which hemisphere takes part in language
processing.

Evidence

• Dichotic listening test

(Kimura 1967; Obler and

Gjerlow 1999) – a participant puts on
headphones; then two different speech signals
are played, each into different ears; the
participant has to repeat the words aloud.

• Most participants repeated the word played into

the right ear (i.e. they showed a right ear
advantage) – proof

that the left hemisphere

processes linguistic signals

and the right

hemisphere – non-linguistic signals.

Language and the brain

• The majority of normal human beings (about

90%) have speech located primarily in the

left

hemisphere.

• Other researchers discovered that the left

hemisphere seems to be linked to

right-

handedness

– Most humans are right-handed, and most people’s

speech is controlled by the left hemisphere.

Language functions: (usually) the left

hemisphere

Language functions: (usually) the left

hemisphere

1. Broca’s area

– a region in the human brain

with functions linked to

speech production

– In the 1860s, a French surgeon, Paul Broca,

reported that damage to this part of the brain
was related to great difficulty in producing speech.

• Recent studies show that Broca’s area also

plays an important role in language
understanding.

Language functions: (usually) the left

hemisphere

2. Wernicke’s area

– a region in the brain

involved in the understanding of written and
spoken language.

– In the 1870s, a German doctor, Carl Wernicke,

reported that damage to this part of the brain
caused speech complrehension problems.

3. The motor cortex

– an area that generally

controls movement of the muscles (of hands,
feet, facial muscles, etc.)

2014-04-22

Language functions: (usually) the left

hemisphere

4. The arcuate fasciculus

- a bundle of nerve fibres which form a vital
connection between Wernicke’s and Broca’s
areas.

• Damage to each of these brain areas (often

because of stroke or head injury) may cause
various problems with producing or
understanding language.

• This condition is called

aphasia

The localization view

• is a way of describing how the brain processes

language:

– The brain follows a certain pattern when it is actively

involved in hearing a word, understanding it, and then

saying it.

1. The word is heard and understood via the Wernicke’s

area.

2. The signal is then sent via the arcuate fasciculus to

Broca’s area – there preparations are made to

produce it.

3. A signal is sent to the motor cortex to physically

articulate the word.

Minor language production difficulties

• Problems with getting the brain and speech

production to work together smoothly may
provide possible

clues

how our linguistic

knowledge is organized within the brain

• The tip of the tongue phenomena

(malapropisms)

– we feel that some word is

eluding us, that we know the word but it just
won’t come to the surface.

– E.g. a speaker wanted to name a particular

navigational instrument (

sextant

) but kept producing

secant, sextet

and

sexton

Minor language production difficulties

• Slip of the tongue

– producing expressions in

which the first letters of words or whole words
are transposed, e.g.

a long shory stort

(instead of

a long story short

), or

use the door to open the

key

– Slips of the tongue are also called spoonerisms after

William Spooner, an Anglican clergyman at Oxford
University, who was renowned for his tongue-slips,
e.g.

– He was killed by a blushing crow

(He was killed by a

crushing blow).

Minor language production difficulties

• Slips of the ear

– show how the brain tries to

make sense of the auditory signal it receives.

– E.g. someone says

gray tape

but you’ve heard

great ape

• Perhaps some Malapropisms originate as slips

of the ear.

• However, some problems with language

production and comprehension result from
more serious disorders in brain function.

Broca’s aphasia (motor aphasia)

• Damage to Broca’s area frequently disrupts

the ability to speak

– The patient’s speech becomes

slow

and

distorted

;

functional morphemes

(e.g. articles, prepositions)

and

inflections

tend to be

omitted

, while only

lexical morphemes (i.e. nouns, verbs, etc.) are left.

– Such patients often additionally suffer from

paralysis or weakening of the right arm and leg,
because this region of the brain also controls body
movement.

2014-04-22

Wernicke’s aphasia

• Damage to Wernicke’s area often

destroys

language comprehension

– Patients produce grammatical speech without

effort, but

they can’t convey the meaning

– They usually have no body weakness, because this

area is far from the parts controlling movement.

Conduction aphasia

• Damage to the arcuate fasciculus results in

patients producing and understanding speech
well, but being

unable to repeat what has

been said

– Patients may

mispronounce

words and may have

disrupted rhythm

because of pauses and

hesitations.

Aphasia

• This classification of various types of aphasia

is an over-simplification:

– recent studies have shown that

it is impossible to

connect precisely brain areas and the traditional
symptom classifications

– Serious damage to either area typically

disrupts

all aspects of speech

– There are patients with damaged Broca’s or

Wernicke’s areas who

don’t suffer any language

disorder