This document provides an overview of aphasia, including definitions, characteristics, causes, types and studies. Aphasia is defined as an acquired language impairment caused by brain damage, characterized by difficulties with speech, comprehension and word-finding. The main types discussed are Broca's aphasia (non-fluent speech with good comprehension) and Wernicke's aphasia (fluent but meaningless speech with poor comprehension). Conduction aphasia involves difficulty repeating words. The document reviews several studies examining language processing in aphasic patients and the relationship between phonological and morphological impairments.

1. Aphasia

2. Definitions of aphasia
There are many definitions about aphasia.
• Darley, Aronson & Brown (1975) assert that ‘aphasia is a
multi-modality reduction in the capacity to decode and
encode meaningful linguistic elements’.
• Kertesz (1985) defined ‘aphasia as an acquired loss of
language due to cerebral damage, characterized by
errors in speech, impaired comprehension, and wordfinding difficulties’.(Benson & Ardila, 1996)
• Finally, aphasia has arisen by brain damage which
causes language disorders. It is associated with an
amount of deficits in language comprehension and
production. (Gazzaniga et al, 1998)
• The term aphasia can be called sometimes dysphasia.
(Smyth et al, 1996)

3. Characteristics
Some of the general characteristics of aphasia are
the following:
• Lack of understanding
• Lack of producing spoken language (e.g.
conversations)
• Reading & writing problems
Finally, aphasia seems to has direct impact on
personal relationships, employment, and social
rehabilitation. (Townend et al, 2007)

4. Etiology
• Seizure disorders (Landav-Kleffner syndrome)
• Vascular disorders (ischemic
stroke/hemorrhagic stroke)
• Traumatic disorders (head injury)
• Brain tumors
• Cancer treatments (radiotherapy/chemotherapy)
• Infectious conditions (viral, bacterial
microorganisms)
• Hypoxic disorders (anoxia)
• Metabolic disorders (Farah & Feinberg, 2000).

5. Types of aphasia
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Broca
Wernicke
Conduction
Global
Transcortical motor
Transcortical sensory
Mixed transcortical
Anomic striatocapsular
Thalamic (Biller, 2008)

6. Diagnosis of aphasia
Many tools can be used for diagnosis of aphasia :
• Boston Diagnostic aphasia examination
• Western Aphasia battery
• Aphasia Diagnostic profiles
• Examining of aphasia
• Aphasia language Performance Scale
• Sklar Aphasia Scale
• Bedside Evaluation & Screening test of aphasia
• Minnesota test for the differentical diagnosis of
aphasia (Johnson, 2007)

7. Study on aphasia
• Miceli et al (2004) in order to understand the
association between phonological &
morphological procedure, they investigated in
depth the continual performance of 26 members.
• They appeared morphological errors in a specific
screening battery of aphasia.
• The relation between morphological &
phonological errors is incoherent.
• The members who made morphological errors
also made phonological, whereas some
aphasics who made phonological errors did not
produce morphological.

8. Broca’s aphasia
During 19th century
phrenologists found out
that specific brain injuries
are possible to cause
specific functional
damages (Gazzaniga et
al, 1998).
A main separation has been
done between Broca’s
and Wernicke’s aphasia.

9. Broca’s aphasia
• Broca’s aphasia is also known as expressive
aphasia.
• It was found out by the French surgeon Paul
Broca in 1861.
• Broca examined patients after a stroke, who
were not often capable to express themselves
by more than a word at a time.
• Although, nouns & verbs were usually
pronounced, they had difficulty in articles,
conjunctions & agrammatical inflections. (Canoll,
1999)

10. Broca’s aphasia
•
•
•
Broca’s area in the left frontal
region is very near to that part of
the motor strip that controls the
tongue & lips and damage to
Broca’s area cause the aphasic
syndrome, called Broca’s aphasia.
(Gleason, 1997)
It has been known that Broca’s
aphasia is caused by damage in
Broca’s area, while Mohr has
indicated that damage constrained
to the Broca’s area produce only
transient language disorders.
Broca’s aphasia follows larger
damages involving Broca’s area
(Gianfranco, 1998).
However the question whether
there is a correlation between
Broca’s aphasia & Broca’s area is
still ambiguous (Gazzaniga et al,
1998).

11. Broca’s aphasia
Some distinctive characteristics of Broca’s aphasia
are:
i. Broca’s aphasics encounter speaking
problems such as pauses & slips of the
tongue.
ii. They have difficulty in words, such as “a, the ,
of”’.
iii. They make ungrammatical sentences.
iv. They have difficulty in using syntactic
information
v. Good comprehension (Hunt & Ellis, 1999,
Gleason, 1997).

12. Studies on broca’s aphasia
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Braber et al (2005) based on previous research of Bird et al,
examined 10 non-fluent aphasic patients.
The main purpose was to use a large framework of errors caused by
the aphasics in skills such as reading, repetition & sentence
completions for regular & irregular verbs.
The aim was to expand their comprehension of the association
between morphological & phonological impairments.
The patients were administered with 3 different tasks related to
speech: single world reading, immediate repetition & sentence
completion.
The central phonological deficits of patient were direct affected by
the big amount of errors in repetition, reading & sentence
completion, it could be ranked as either similar or non similar
phonological errors.
The majority of errors is connected with regular past-tenses forms
due to a hidden phonological rather than a morphological deficit.

13. Studies on broca’s aphasia
• Researchers tested the understanding of
complementizers such as that & if and verb inflections by
English agrammatic broca’s aphasics speakers.
• The study involved 2 experiments. In the 1st experiment
members heard clause sentences, while in the 2nd
experiment they heard sentences with finite auxiliaries &
sentences with finite verbs & control sentences with
uninflected verbs.
• According to the results there is a separation in the
classes of functional morphology. Grammaticality
assessment for complementizers is relatively spared.
• The perception of verbal inflection is more influenced.
• The specific results confirm previous surveys & show
that the patients with agrammatic broca’s aphasia incline
to some but not all kinds of syntactic structure. (Dickey et
al 2005)

14. Wernicke’s aphasia
• Another type of aphasia
is Wernicke’s aphasia
which is a result from
injury to an area in the
temporal lobe in the left
hemisphere (Best, 1999).
• Another name of
Wernicke’s aphasia is
receptive aphasia
(Canoll, 1999).

15. Wernicke’s aphasia
Some of characteristics are the below:
i. Fluent , rapid speech
ii. Well-structured syntax
iii. Function words
iv. Articulatory problems
v. Prosodic difficulties
vi. Repetition problems
vii. Comprehension is poor
viii. Word-finding problems
ix. Paragrammatic errors (Field, 2003, Yudofsky & Hales,
2004, Harley, 1996, Gleason, 1997)

16. Study
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A study conducted by Nakano & Blumstein (2004) examined how normal
people & broca’s & wernicke’s aphasics unite thematic information
increasingly using syntax, lexical-semantics & pragmatics in an active
declarative sentence.
3 experiments were carried out with the use of an auditory lexical decision
task in which members made a lexical decision on a “target” prefaced by a
prime.
Normal participants appeared evidence for connective thematics important
& larger percentage of thematic priming.
Also, they appeared inclination to both syntactic structures & pragmatics.
Although, broca’s aphasics didn’t appear important priming for any situation
nor did they appear similarity in the magnitude of priming among the
conditions, nonetheless they showed sensitivity to pragmatics.
Wernicke’s patients tend to show substantial priming for all conditions, but
did not appear differences in the magnitude of priming among the
conditions.
Also, they showed tendency to sentence grammaticality & pragmatics.

17. Conduction aphasia
• Conduction aphasia is
caused by lesions in
either the superior
temporal or inferior
parietal areas
(Bradley, 2003).

18. Conduction aphasia
Patients with conduction aphasia disorder have:
1. Inability to repeat
2. Normal speech comprehension & production
Aphasics people have the aknowledgement that
they have language problems & will try to
correct their errors (Emilier et al, 2004, Martin,
2006)

19. Studies on conduction aphasia
• Balasubramanian (2005) examines the word level writing
in 2 conduction aphasics and tries to explore the parallel
association between speech production deficits and
deficits in written expression.
• They were a 66-year-old female with left posterior
parietal lobe lesion & a 65-year-old female with a left
posterior temporo-parietal lobe lesion.
• Both cases were examined by Boston Naming Test
(BNT) & written naming task (JHDB).
• Both patients have appeared phonological & semantic
paraphasias on BNT,although a 65-year-old woman had
better performance than that of 66-year-old woman.
• 66-year-old female appeared many reactions to stimuli
compared to 65-year-old female.
• 65-year-old woman’s performance on the written naming
task was worst to that of 66-year-old woman.

20. Studies on conduction aphasia
• Hickok et al (2000) tested the hypothesis that at
least 1 form of conduction aphasia is caused
from damage to cortical fields in the left posterior
superior temporal gyrus, which is involved not
only in speech perception, but also in phonemic
aspects of speech production.
• The researchers conducted 4T fMRI in which
members named visually presented objects subvocally.
• The results indicate that the majority of
participants appeared activation in 2 regions on
the dorsal portion of the left posterior superior
temporal gyrus.

21. References
Balasubramanian. V. (2005). Dysgraphia in two forms of conduction aphasia. Brain and
cognition, 57, 8-15.
Benso. D. F. & Ardila. A. (1996). Aphasia: A clinical perspective. UK: Oxford University
Press
Best. J. B. (1999). Cognitive Psychology. (5th ed). USA: Wadsworth Publishing Company
Biller. J. (2008). Practical Neurology. USA: Lippincot Williams & Wilkins
Braber. N.et al. (2005). The relationship between phonological and morphological deficits
in Broca’s aphasia: Further evidence from errors in verb inflection. Brain and
language, 92, 278-287
Bradley. W. G.et al. (2003). Neurology in clinical practice. UK: Taylor & Francis
Canoll. D. W. (1999). Psychology of language (3rd ed). USA: Brooks/cole publishing
Dickey. M. W.et al. (2005). Perception of functional morphology in agrammatic Broca’s
aphasia. Brain and Language, 95, 82-83
Emilier. G.et al. (2004). Memory: neuropsychological, imaging and
psychopharmacological perspectives. UK: Psychology Press
Farah. M. J. & Feinberg. T. E. (2000). Patient-based approaches to cognitive
neuroscience USA: MIT Press

22. References
Field. J. (2003). Psycholinguistics: A resource book for students. London: Routledge
Gazzaniga. M. S.et al. (1998). Cognitive neuroscience. USA: W.W. Norton and Company
Gianfranco. D. (1998). Handbook of clinical and experimental neuropsychology. UK:
Psychology Press
Gleason. J. B. (1997). The development of language (4th ed). USA: Allyn and Bacon
Harley. T. A. (1996). The Psychology of Language. UK: Psychology Press
Hickok. G.et al. (2000). A functional magnetic resonance imaging study of the role of left
posterior superior temporal gyrus in speech production: implications for the
explanation of conduction aphasia. Neuroscience letters, 287, 156-160
Hunt. R. R. & Ellis. H. C. (1999). Fundamentals of cognitive psychology (6th ed). USA:
McGraw-Hill College
Johnson. A. F. (2007). Medical Speech language pathology: A practitioner’s guide. USA:
Thieme
Martin. G. N. (2006). Human neuropsychology. UK: Pearson educations
Miceli. G.et al. (2004). The relationships between morphological and phonological errors
in aphasic speech: data from a word repetition task. Neuropsychologia, 42, 273-287
Nakano. H. & Blumstein. S. E. (2004). Deficits in thematic integration processes in
Broca’s and Wernicke’s aphasia. Brain and language, 88, 96-107
Smyth. M. M.et al. (1996). Cognition in action (2nd ed). UK: Psychology Press
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