Speech/Language Function
BCS 242 Neuropsychology
Fall 2004
Brief Anatomy
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In >96% of right-handers and 70% of lefthanders, left hemisphere is “dominant” for
speech and language
Different areas implicated in different
functions
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For example, anterior location for speech
production (left frontal lobe); posterior for speech
comprehension (left temporal-parietal region)
Roles played by subcortical structures (basal
ganglia, posterior thalamus) and right hemisphere
less well understood
Brain areas involved in Language
Basic Language Components
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Auditory Comprehension
Visual Comprehension
Articulation
Word Finding
Grammar/Syntax
Repetition
Verbal Fluency
Writing
Prosody
Language Deficits
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Aphasia – spoken language
Alexia – reading
Agraphia - writing
Anomia - naming
Dysarthria - articulation
Types of Language Errors
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Paraphasia:
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Neologism:
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Talking with considerable effort
Agraphia:
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Paraphasia with a completely novel word
Nonfluent speech:
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Substitution of a word by a sound, an incorrect word, or an
unintended word
Impairment in writing
Alexia:
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Disturbances in reading
19th Century Neuropsychology
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Broca (1865) described patients who
displayed halting, agrammatic speech
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Content words were well preserved
Function words (i.e., adjectives, articles)
impaired
Broca’s Aphasia
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Patient “Tan”
Brain tumor in Left frontal brain region
Broca: Lesion disrupted speech
Broca’s Aphasia
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“Yes… ah… Monday… er… Dad and Peter
H… (patient’s name), and Dad… er…
hospital… and ah… Wednesday…
Wednesday, nine o’clock… and oh…
Thursday… ten o’clock, ah doctors… two…
an’ doctors… and er… teeth…yah
Goodglass & Geschwind, 1976
Broca’s Aphasia
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Broca’s Aphasia – Damage to “motor images”
Language comprehension skills relatively
preserved
Typically observed in patients with damage to
left inferior prefrontal cortex
Wernicke’s Aphasia
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Neologisms
Speech appears to have no information content
“fluent nonsense”
Preserved function words, impaired content words
Comprehension impaired
Even simple sentences not well understood
Associated with left temporal lobe damage
Wernicke’s Aphasia
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“Well this is… mother is away here working
her work out o’here to get her better, but
when she’s looking in the other part. One
their small tile into her time here. She’s
working another time…”
Goodglass & Geschwind, 1976
Broca’s, Wernicke’s Area, and Connections
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Lichtheim’s (1885) and Geschwind’s (1965)
model
Auditory input mediated by Wernicke’s area
Motor output mediated byBroca’s area
Regions connected by arcuate fasciculus
Aphasia Syndromes I
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Fluent (receptive) Aphasias: All have FLUENT
speech and no articulatory disorder; problems
with comprehension and/or repetition
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Wernicke (aka sensory): neologisms/anomia/
paraphasias, poor comprehension and repetition
Transcortical Sensory(aka isolation syndrome):
intact repetition; paraphasias/anomia, poor
comprehension
Conduction: phonemic paraphasias/neologisms,
poor repetition, fairly good comprehension
Anomic (aka amnesic):anomia and some
paraphasias; all else intact
Aphasia Syndromes II
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Nonfluent (expressive) Aphasias: All have
articulatory disorder but relatively preserved
comprehension
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Broca (aka motor, expressive, nonfluent):
speechlessness with recurring utterances or
phonetic disintegration, or phonemic paraphasias
with anomia, agrammatism, and dysprosody; poor
repetition
Transcortical Motor: uncompleted sentences
and anomia; naming better than spontaneous
speech; repetition fairly intact
Global: speechlessness with recurring utterances,
poor comprehension, poor repetition
Aphasia Syndromes III
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“Pure” Aphasias – selective impairments
with NORMAL speech production
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Alexia without Agraphia: poor reading
Agraphia: poor writing
Word Deafness: poor comprehension, poor
repetition
Major Aphasia Syndromes
Type
Production
Comp.
Repetition
Naming
Global
impaired
impaired
impaired
impaired
Broca’s
not fluent
intact
limited
limited
Wernicke’s
fluent/
impaired
impaired
impaired
impaired
Anomic
fluent/
intact
circumlocutory
intact
impaired
Mixed/
nonfluent
impaired
limited
limited
Conduction
fluent/
intact
circumlocutory
impaired
limited
limited
Right Hemisphere Contribution
to Language Functions
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Good comprehension for gestural
language
Prosody (inflection, timbre, melody)
Semantic language (word recognition,
verbal meaning, concepts, and
especially visual meaning)
Assessment of Language
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Standard Aphasia Batteries (e.g.,
Western Aphasia Battery, Boston
Diagnostic Aphasia Exam, Halstead
Aphasia Screening Test)
Boston Naming Test
Token Test
Verbal Fluency
Written Expression (e.g., Cookie Theft)