 specific functions on specific to one side of the cortex rather than bilateral

 brain injuries  “split brain” patients  imaging studies

 left hemisphere ◦ analytical abilities ◦ quantitative skills ◦ language  right hemisphere ◦ 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 20079

 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.

 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

Copyright © Allyn & Bacon 2007 Part of the Boston Diagnostic Aphasia Test

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

 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

 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

 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

 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

 0U&feature=fvsr 0U&feature=fvsr  rQ&feature=related

 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