Speech

1. Language is one of the fundamental Language is one of the fundamental
bases of human intelligence and a bases of human intelligence and a
key part of human culture. key part of human culture.
Physiology of LanguagePhysiology of Language

2. The primary brain areas concerned with language The primary brain areas concerned with language
are arrayed along and near the sylvian fissure are arrayed along and near the sylvian fissure
(lateral cerebral sulcus) of the categorical (lateral cerebral sulcus) of the categorical
hemisphere. hemisphere.
 A region at the posterior end of the superior A region at the posterior end of the superior
temporal gyrus called temporal gyrus called Wernicke’s areaWernicke’s area is is
concerned with comprehension of auditory and concerned with comprehension of auditory and
visual information. visual information.
It projects via the arcuate fasciculus toIt projects via the arcuate fasciculus to Broca’s Broca’s
area (area 44)area (area 44) in the frontal lobe. in the frontal lobe.
Anatomy of language areas

3. Broca’s area processes the information received from Broca’s area processes the information received from
Wernicke’s area into a detailed and coordinated pattern for Wernicke’s area into a detailed and coordinated pattern for
vocalizationvocalization
 and then projects the pattern via a speech articulation area and then projects the pattern via a speech articulation area
in the insula to the motor cortex, which initiates the in the insula to the motor cortex, which initiates the
appropriate movements of the lips, tongue, and larynx to appropriate movements of the lips, tongue, and larynx to
produce speech.produce speech.
The angular gyrus behind Wernicke’s area appears to The angular gyrus behind Wernicke’s area appears to
process information from words that are read in such a way process information from words that are read in such a way
that they can be converted into the auditory forms of the that they can be converted into the auditory forms of the
words in Wernicke’s area.words in Wernicke’s area.

4. Location of language areas

5. The probable
sequence
of events
when a subject
names
a visual object
(horizontal
section of hum-
an brain)

6. It is interesting that in individuals who It is interesting that in individuals who
learn a second language in adulthood, learn a second language in adulthood,
fMRI reveals that the portion of Broca’s fMRI reveals that the portion of Broca’s
area concerned with it is adjacent to but area concerned with it is adjacent to but
separate from the area concerned with the separate from the area concerned with the
native language. native language.
 However, in children who learn two However, in children who learn two
languages early in life, there is only a single languages early in life, there is only a single
area involved with both.area involved with both.

7. AphasiasAphasias
Aphasias are abnormalities of language Aphasias are abnormalities of language
functions that are not due to defects of functions that are not due to defects of
vision or hearing or to motor paralysis. vision or hearing or to motor paralysis.
They are caused by lesions in the They are caused by lesions in the
categorical hemisphere. categorical hemisphere.
The most common cause is embolism or The most common cause is embolism or
thrombosis of a cerebral blood vessel.thrombosis of a cerebral blood vessel.
Fluent, nonfluent, and anomic aphasias.Fluent, nonfluent, and anomic aphasias.

8.  In nonfluent aphasia (EXPRESSIVE
APHASIA, ANTERIOR APHASIA)
the lesion is in Broca’s areathe lesion is in Broca’s area
 Speech is slow, and words are hard to come by. Speech is slow, and words are hard to come by.
Patients with severe damage to this area are Patients with severe damage to this area are
limited to two or three words with which to express limited to two or three words with which to express
the whole range of meaning and emotion.the whole range of meaning and emotion.
The words retained are those which were being The words retained are those which were being
spoken at the time of the injury or vascular spoken at the time of the injury or vascular
accident that caused the aphasia.accident that caused the aphasia.

9. Fluent AphasiaFluent Aphasia ( ( RECEPTIVE APHASIA, RECEPTIVE APHASIA,
POSTERIOR APHASIA) POSTERIOR APHASIA)
Lesion in the wernicke’s areaLesion in the wernicke’s area
Speech itself is normal and sometimes the Speech itself is normal and sometimes the
patients talk excessively. patients talk excessively.
 However, what they say is full of jargon and However, what they say is full of jargon and
neologisms that make little sense. neologisms that make little sense.
The patient also fails to comprehend the The patient also fails to comprehend the
meaning of spoken or written words.meaning of spoken or written words.

10. conduction aphasiaconduction aphasia
Lesion in the auditory cortex (areas 40, 41 Lesion in the auditory cortex (areas 40, 41
&42)&42)
patients can speak relatively well and have atients can speak relatively well and have
good auditory comprehension but cannot put good auditory comprehension but cannot put
parts of words together or conjure up words. parts of words together or conjure up words.
This is called conduction aphasia because it This is called conduction aphasia because it
was thought to be due to lesions of the was thought to be due to lesions of the
arcuate fasciculus connecting Wernicke’s and arcuate fasciculus connecting Wernicke’s and
Broca’s areas.Broca’s areas.

11. anomic aphasiaanomic aphasia
When there is a lesion damaging the When there is a lesion damaging the
angular gyrus. angular gyrus.
There is trouble understanding written There is trouble understanding written
language or pictures, because visual language or pictures, because visual
information is not processed and information is not processed and
transmitted to Wernicke’s area.transmitted to Wernicke’s area.

12. Type of Aphasia andType of Aphasia and
Site of LesionSite of Lesion
Characteristic NamingCharacteristic Naming
ErrorsErrors
Nonfluent (Broca’s area)Nonfluent (Broca’s area)
Fluent (Wernicke’s area)Fluent (Wernicke’s area)
Fluent (areas 40, 41 and 42;Fluent (areas 40, 41 and 42;
conduction aphasia)conduction aphasia)
Anomic (angular gyrus)Anomic (angular gyrus)
““Tssair”Tssair”
““Stool” or “choss”Stool” or “choss”
(neologism)(neologism)
““Flair . . . no, swair . . . Flair . . . no, swair . . .
tair”tair”
““I know what it is . . . I know what it is . . .
I have a lot of them”I have a lot of them”
Aphasias. Characteristic responses ofAphasias. Characteristic responses of
patients with lesions in various areas whenpatients with lesions in various areas when
shown a picture of a chairshown a picture of a chair

13. Motor AphasiaBroca's Area Causes
unable to interpret the thought
Sensory Aphasia
Wernicke's Aphasia
Global Aphasia
word blindness called dyslexiavisual association
areas
word deafness auditory association
areas
LESION FAETURESAREA

14. DyslexiaDyslexia
which is a broad term applied to impaired ability which is a broad term applied to impaired ability
to read, due to an inherited abnormality.to read, due to an inherited abnormality.
Causes of Dyslexia:Causes of Dyslexia:
•Reduced ability to recall speech sounds, so Reduced ability to recall speech sounds, so
there is trouble translating them mentally into there is trouble translating them mentally into
sound units (phonemes).sound units (phonemes).
•There is a defect in the magnocellular portion There is a defect in the magnocellular portion
of the visual system that slows processing of the visual system that slows processing
and also leads to phonemic deficit.and also leads to phonemic deficit.
•There is decreased blood flow in angular There is decreased blood flow in angular
gyrus in categoricalgyrus in categorical hemisphere in both hemisphere in both
cases.cases.

15. GLOBAL APHASIA
(CENTRAL APHASIA)
This means the combination of the
expressive problems of Broca's aphasia and
the loss of comprehension of Wernicke's.
The patient can neither speak nor understand
language.
 It is due to widespread damage to speech
areas and is the commonest aphasia after a
severe left hemisphere infarct.
Writing and reading are also affected.

16. Lesions limited to the left temporal poleLesions limited to the left temporal pole
(area 38) cause inability to retrieve names (area 38) cause inability to retrieve names
of places and persons but preserves the of places and persons but preserves the
ability to retrieve common nouns.ability to retrieve common nouns.
StutteringStuttering, associated with right cerebral , associated with right cerebral
dominance and widespread overactivity dominance and widespread overactivity
in the cerebral cortex, cerebellum andin the cerebral cortex, cerebellum and
supplementary motor area.supplementary motor area.

17. An important part of the visual input goes to the An important part of the visual input goes to the
inferior temporal lobe, where representations of inferior temporal lobe, where representations of
objects, particularly faces, are stored.objects, particularly faces, are stored.
In humans, storage and recognition of faces is
more strongly represented in the right inferior
temporal lobe in right-handed individuals,
though the left lobe is also active.
 Lesions in this area cause Lesions in this area cause prosopagnosiaprosopagnosia, the , the
inability to recognize faces. inability to recognize faces.
 They can recognize people by their voices, and They can recognize people by their voices, and
many of them show autonomic responses when many of them show autonomic responses when
they see familiar as opposed to unfamiliar faces. they see familiar as opposed to unfamiliar faces.
However, they cannot identify the familiar faces However, they cannot identify the familiar faces
they see.they see.

19. DYSARTHRIA
Slurred speech.
Language is intact
Paralysis, slowing or incoordination of muscles of
articulation or local discomfort causes various different
patterns of dysarthria.
DISORDERED ARTICULATION
Examples
•'gravelly' speech of upper motor neurone lesions of
lower cranial nerves,
• jerky, ataxic speech of cerebellar lesions (Scanning
Speech),
•the monotone of Parkinson's disease (Slurred),
•speech in myasthenia that fatigues and dies away.
Many aphasic patients are also somewhat dysarthric.

20. In the inferior portion of the left frontal In the inferior portion of the left frontal
lobe there is an area concerned with lobe there is an area concerned with
number facts and exact calculations. number facts and exact calculations.
 Frontal lobe lesions can cause Frontal lobe lesions can cause
acalculia, a selective impairment of acalculia, a selective impairment of
mathematical abilitymathematical ability..
Accurate navigation in humanAccurate navigation in human
1.One is the 1.One is the right hippocampusright hippocampus, which is , which is
concerned with learning where places are concerned with learning where places are
located, located,
2.and the other is the 2.and the other is the right caudate right caudate
nucleusnucleus, which facilitates movement to , which facilitates movement to
the places.the places.

21. The greater brain weight of men is due to The greater brain weight of men is due to
more neural components involved in more neural components involved in
getting from place to place and that this is getting from place to place and that this is
why men resist asking directions when why men resist asking directions when
lost, whereas women do not hesitate to lost, whereas women do not hesitate to
seek help.seek help.

22. Brain Areas Concerned with LanguageBrain Areas Concerned with Language
Wernick’s AreaWernick’s Area
Broca’a AreaBroca’a Area
Speech articulation Area in Speech articulation Area in
InsulaInsula
Motor CortexMotor Cortex
Angular GyrusAngular Gyrus

23. ANOMIC
NON FLUENT
GLOBAL
APHASIA
FLUENT
BROCA'S AREA
• WERNICK’S AREA
CONDUCTION APHASIA
ANGULAR GYRUS
WIDESPREAD DAMAGE TO
SPEECH AREAS
EXPRESSIVE RECEPTIVE

24. THANK YOU
Acknowledgement to
Prof Fawazia Al-Rouq