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specific functions on specific to one side of
the cortex rather than bilateral
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brain injuries
“split brain” patients
imaging studies
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left hemisphere
◦ analytical abilities
◦ quantitative skills
◦ language
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right hemisphere
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◦
◦
◦
◦
music
spatial abilities
artistic abilities
emotions
facial recognition

most well studied
lateralized behavior
◦ 95% of right handed have
speech on left
◦ 70% of left handed have
speech on left

aphasia – language deficit
that cannot be attributed to
motor, motivational,
sensory or other
explanations


characterized by
broken halted
speech, absence of
prosody
non-fluent aphasia
Frontal lobe

agrammatism
◦ difficulty in comprehending or properly employing
grammatical devices, such as verb endings and word
order.

anomia
◦ Difficulty in finding (remembering) appropriate word

articulation
◦ difficulty mispronouncing words
Copyright © Allyn & Bacon 2007
9


Can’t just be motor or it wouldn’t be an
aphasia
Grammatical issues with connecting words

The lion was killed by the leopard.

lion
killed
leopard.
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Can’t just be motor or it wouldn’t be an
aphasia

Grammatical issues with connecting words

Non-fluent aphasia

Comprehension – fairly good; ability to read –
fairly good
Part of the Boston Diagnostic Aphasia Test
Copyright © Allyn & Bacon 2007
Copyright © Allyn & Bacon 2007

deficits observed depend on individual as well
as where in this region damage occurs…
◦ fmri studies…..
◦ INSULAR CORTEX – speech articulation?
◦ apraxia?
Copyright © Allyn & Bacon 2007



fluid aphasia, deficits
appear to be in
comprehension;
words are nonsensical
comprehension – poor
reading ability - poor
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recognition of spoken words
comprehension of meaning of words
ability to convert thoughts into words
How do we test comprehension in someone
that may have Wernicke’s Aphasia?

surgical requirements


injection of sodium
amytal or sodium
amobarbital –
anesthetic
used to determine
hemisphere
important for
speech

split brain surgery

initially –
◦ odd behaviors ◦ subsequently – only can really tell by experimental
manipulations in the lab
◦ Julian Jaynes – “Breakdown of the Bicameral Mind”

Functional brain imaging
◦ fMRI or PET used to see which half is active when
doing a language test
Copyright © 2006 by Allyn and
Bacon
Copyright © 2006 by Allyn and
Bacon

apraxia (of speech)- speech disorder with
difficulty speaking correctly; not due to
weakness or paralysis of speech muscles
(NIDCD); complex motor commands

acquired
◦ most typically in adults after brain damage

developmental
◦ appears present from birth
◦ affects boys more than girls
◦ other names – verbal dyspraxia, articulatory
apraxia, childood speech apraxia
◦ different than developmental delay of speech
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cause or causes unknown
may be related to language development
may be neurological disorder
no specific lesions or imaging studies helpful
family history of communication disorders or
learning disabilities
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difficulty putting sounds and syllables
together in correct order
longer words more difficult than short
inconsistent speech (say word and then
unable)
children – comprehension much better than
expression
severity can vary widely


http://www.youtube.com/watch?v=szjfC9K19
0U&feature=fvsr
http://www.youtube.com/watch?v=XNB0ihI2s
rQ&feature=related

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genetic component
family studies
twin studies
complex in terms of genes
complex in terms of etiology
complex in terms of traits
◦ can include phonological, auditory, motor, visual
deficits which make reading even more difficult