Editing Split-brain (section)

=== Patient JW ===

Funnell et al. (2007) tested patient JW some time before June 2006.<ref name = Funnellet2007>{{cite journal |author1=Funnell M. G. |author2=Colvin M. K. |author3=Gazzaniga M. S. | year = 2007 | title = The calculating hemispheres: Studies of a split-brain patient | journal = Neuropsychologia | volume = 45 | issue = 10| pages = 2378–2386 | doi=10.1016/j.neuropsychologia.2007.01.017 | pmid=17420034|s2cid=21620141 }}</ref> They described JW as

{{Blockquote
|text=a right-handed male who was 47 years old at the time of testing. He successfully completed high school and has no reported learning disabilities. He had his first seizure at the age of 16 and the age of 25, he underwent a two-stage resection of the corpus callosum for relief of intractable epilepsy. Complete sectioning of the corpus callosum has been confirmed by MRI.<ref name=":0">{{Cite journal|last1=Gazzaniga|first1=M. S.|last2=Holtzman|first2=J. D.|last3=Deck|first3=M. D.|last4=Lee|first4=B. C.|date=1985-12-01|title=MRI assessment of human callosal surgery with neuropsychological correlates|journal=Neurology|volume=35|issue=12|pages=1763–1766|issn=0028-3878|pmid=4069368|doi=10.1212/wnl.35.12.1763|s2cid=39978354}}</ref> Post-surgical MRI also revealed no evidence of other neurological damage.{{verify inline|reason=Citation seems misplaced. Is this text after the citation part of the quotation or not?|date=September 2023}}
}}

Funnell et al.'s (2007) experiments were to determine each of JW's hemisphere's ability to perform simple addition, subtraction, multiplication and division. For example, in one experiment, on each trial, they presented an arithmetic problem in the center of the screen for one second, followed by a central crosshair JW was to look at. After one more second, Funnell et al. presented a number to one or the other hemisphere / visual field for 150 ms—too fast for JW to move his eyes. Randomly in half the trials, the number was the correct answer; in the other half of the trials it was the incorrect answer. With the hand on the same side as the number, JW pressed one key if the number was correct and another key if the number was incorrect.<ref name = Funnellet2007 />

Funnell et al.'s results were that performance of the left hemisphere was highly accurate (around 95%)—much better than performance of the right hemisphere, which was at chance for subtraction, multiplication, and division. Nevertheless the right hemisphere showed better-than-chance performance for addition (around 58%).<ref>{{cite journal |last1=Funnell |first1=Margaret G. |title=The calculating hemispheres: studies of a split-brain patient |journal=Neuropsychologia |date=2007 |volume=45 |issue=10 |pages=2378–2386 |doi=10.1016/j.neuropsychologia.2007.01.017 |pmid=17420034 |s2cid=21620141 |url=https://www.sciencedirect.com/science/article/pii/S002839320700053X|url-access=subscription }}</ref>

Turk et al. (2002) tested hemispheric differences in JW's recognition of [[self-recognition|himself]] and of familiar faces.<ref>{{cite journal |author1=Turk D. J. |author2=Heatherton T. F. |author3=Kelley W. M. |author4=Funnell M. G. |author5=Gazzaniga M. S. |author6=Macrae C. N. | year = 2002 | title = Mike or me? Self-recognition in a split-brain patient | journal = Nature Neuroscience | volume = 5 | issue = 9| pages = 841–842 | doi = 10.1038/nn907 |pmid=12195428 |s2cid=36040335 }}</ref> They used faces that were composites of JW's face and Dr. Michael Gazzaniga's face. Composites ranged from 100% JW, through 50% JW and 50% Gazzaniga, to 100% Gazzaniga. JW pressed keys to say whether a presented face looked like him or Gazzaniga. Turk et al. concluded there are cortical networks in the left hemisphere that play an important role in self-recognition.{{citation needed|date=December 2020}}