Insights into the functional specificity of the human corpus callosum

Funnell, Margaret G.; Corballis, Paul M.; Gazzaniga, Michael S.

doi:10.1093/brain/123.5.920

Cited by 105 publications

(47 citation statements)

References 23 publications

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“…However, in this and other split-brain patients, several investigators have noted that transfer of some types of visual information is usually spared [21]. The commonly accepted explanation for residual interhemispheric coordination in split-brain patients is that subcortical pathways suffice to transfer simple visual information [3,21,25]. Our data are consistent with the claim that such subcortical connections operate when the corpus callosum is surgically severed.…”

Section: Discussionsupporting

confidence: 89%

See 1 more Smart Citation

Residual functional connectivity in the split-brain revealed with resting-state functional MRI

Uddin

Mooshagian²,

Zaidel³

et al. 2008

NeuroReport

148

132

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Split-brain patients present a unique opportunity to address controversies regarding subcortical contributions to interhemispheric coordination. We characterized residual functional connectivity in a complete commissurotomy patient by examining patterns of low-frequency BOLD fMRI signal. Using independent components analysis (ICA) and region-of-interest (ROI) based functional connectivity analyses, we demonstrate bilateral resting state networks in a patient lacking all major cerebral commissures. Compared to a control group, the patient's interhemispheric correlation scores fell within the normal range for two out of three regions examined. Thus we provide evidence for bilateral resting state networks in a patient with complete commissurotomy. Such continued interhemispheric interaction suggests that, at least in part, cortical networks in the brain can be coordinated by subcortical mechanisms.

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Section: Discussionsupporting

confidence: 89%

“…These patients can often transfer coarse perceptual visual information between the hemispheres [3]. The common assumption is that this is accomplished by subcortical pathways, which can compensate when low-level information transfer is required [3].…”

Section: Introductionmentioning

confidence: 99%

Residual functional connectivity in the split-brain revealed with resting-state functional MRI

Uddin

Mooshagian²,

Zaidel³

et al. 2008

NeuroReport

148

132

View full text Add to dashboard Cite

show abstract

“…Functional ramifications of the topographic organization of the corpus callosum in humans have been studied by administering cognitive tests to patients with callosal lesions resulting from relatively discrete trauma (e.g., Peru et al 2003) to more extensive surgically induced lesions (e.g., Funnell et al 2000;Gazzaniga 2005). Such studies have illuminated complex patterns of interhemispheric communication as well as compensatory mechanisms that develop when the normal functional connections either fail to develop or are damaged.…”

Section: Discussionmentioning

confidence: 99%

Frontal Callosal Fiber Integrity Selectively Predicts Coordinated Psychomotor Performance in Chronic Alcoholism

Rosenbloom

Sassoon

Fama

et al. 2008

Brain Imaging and Behavior

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“…Interpreted in light of other patient studies (e.g., Brion & Jedynak, 1972;Funnell et al, 2000;Baynes et al, 1997;Kamaki et al, 1993; Marchetti & Della Sala, 1998;Gazzaniga, 2000), these dissociations have implications for the understanding of righthemisphere language capacities, inter-hemispheric communication, and perhaps even consciousness. …”

mentioning

confidence: 85%

Poster Session 1

2001

Brain and Language

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We describe a patient with multiple brain lesions who presents with striking dissociations between verbal and manual responses in a variety of tasks, including visual extinction, recognition of digits and number words, and single-digit addition. Interpreted in light of other patient studies (e.g., Brion & Jedynak, 1972;Funnell et al., 2000;Baynes et al., 1997;Kamaki et al., 1993; Marchetti & Della Sala, 1998;Gazzaniga, 2000), these dissociations have implications for the understanding of righthemisphere language capacities, inter-hemispheric communication, and perhaps even consciousness. Case HistoryWS is a 63-year-old right-handed man with a master's degree in mathematics. He worked as a math instructor at a community college before suffering CVAs in 1998 and 2000. MRI following the more recent incident revealed a new left parietal infarct, older left occipital and anterior callosal lesions, and possible thinning of other callosal regions. A right homonymous hemianopia was present immediately after the earlier CVA, but cleared within six months. At the time of the present study WS had normal acuity and visual fields. Visual ExtinctionAsterisks were presented for 200 ms on a computer monitor. For Left stimuli, a single asterisk was presented to the left of fixation, and for Right stimuli an asterisk was presented to the right of fixation. For Both stimuli, an asterisk was presented both to the left and to the right of fixation.On each trial WS indicated where asterisks had appeared. In the Verbal Response condition he responded by saying ''left,'' ''right,'' or ''both.'' In the Manual Response condition he responded with his right hand, raising his index finger to indicate a Left stimulus, his middle finger for a Right stimulus, and both fingers for a Both stimulus.Results for the Verbal Response condition suggested left neglect with extinction. Whereas WS was 100% correct for Right stimuli (68/68), his accuracy was only 76% for Left stimuli (52/68), and 46% for Both stimuli (63/136). Virtually all of his errors involved failure to report asterisks presented on the left.In the Manual Response condition the results were quite different. Accuracy for Left stimuli (98% (51/52)-and Both stimuli-82% (85/104)) was much higher than in the Verbal Response condition (p Ͻ .001). Also, the majority of errors for Both stimuli (13/19) were failures to report the right stimulus, suggesting a mild right extinction. Accuracy for Right stimuli was 94% (49/52). Digit RecognitionOn each trial a single digit was presented for 200 ms to the left or right of fixation. On Left and Right trials only the digit was presented; on Left-with-X and Rightwith-X trials an X was also presented, on the opposite side of fixation from the digit (see Table 1).WS was instructed to report the digit, ignoring the X when it was present. In the Verbal condition he named the digit, whereas in the Manual condition he held up the appropriate number of fingers (using the left hand for the numbers 1-5, and both hands for 6-9).In the Verbal condition WS was ...

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Insights into the functional specificity of the human corpus callosum

Cited by 105 publications

References 23 publications

Residual functional connectivity in the split-brain revealed with resting-state functional MRI

Residual functional connectivity in the split-brain revealed with resting-state functional MRI

Frontal Callosal Fiber Integrity Selectively Predicts Coordinated Psychomotor Performance in Chronic Alcoholism

Poster Session 1

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