Left-handedness and language lateralization in children

Szaflarski, Jerzy P.; Rajagopal, Amirtham; Altaye, Mekibib; Byars, Anna W.; Jacola, Lisa M.; Schmithorst, Vincent J.; Schapiro, Mark B.; Plante, Elena; Holland, Scott K.

doi:10.1016/j.brainres.2011.11.026

Cited by 114 publications

(95 citation statements)

References 115 publications

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“…The present study was limited to right-handed children who were closely matched for gender, age, and handedness to non-injured control subjects. Although the majority of both right and left handed children are left hemisphere dominant for language, [19] it is unknown whether or to what degree the present results would generalize to left-handed children with TBI. Finally, future studies may consider this issue with larger and more diverse samples of children over time.…”

Section: Limitationsmentioning

confidence: 86%

The Importance of Orientation in Evaluating Recovery in Pediatric Traumatic Brain Injury

Hotz

Plante²,

Helm-Estabrooks³

et al. 2014

Int J Phys Med Rehabil

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Objective: Decisions about whether children who have sustained a traumatic brain injury are ready to transition from a medical facility to home and school life requires insight into their cognitive status. This study evaluates whether orientation to time, place, and self (Ox3) serves as sufficient indicator of general cognitive status to support such decisions.Design: Participants with and without TBI were administered the PTBI in one to three individual testing sessions. Performance on Ox3 items were compared between groups, as well as performance on subtests representing broader cognitive and linguistic skills.Setting: Pediatric brain injury in patient acute and rehab units.Participants: Twenty-eight children with TBI (18 male, 10 female) between the ages of 6 and 16 years of age served as participants. Of these, 12 were initially classified as severe, 6 moderate, and 10 mild on the Glasgow Coma Scale. Interventions: NAMain Outcome Measures: The Pediatric Test of Brain Injury (PTBI) is a criterion-referenced, standardized test designed to measure neurocognitive, language and literacy abilities in children recovering from brain injury. The entire test, including its Orientation subtest, was administered to participants during the acute phase of recovery (within 3 months of injury).Results: Despite no differences between the TBI and control group on the Orientation subtests, deficits occurred in other cognitive-linguistic domains that are relevant to functioning outside medical and rehabilitation environments. Furthermore, even neurologically-normal children sometimes failed some Ox3 items. Conclusion:The findings on Orientation items from the PTBI indicates that caution is warranted in applying the "Ox3" standard for evaluating cognitive status to a pediatric TBI population.

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Section: Limitationsmentioning

confidence: 86%

The Importance of Orientation in Evaluating Recovery in Pediatric Traumatic Brain Injury

Hotz

Plante²,

Helm-Estabrooks³

et al. 2014

Int J Phys Med Rehabil

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“…However, it must be stressed that around 80 % of left-handers exhibit the same typical left lateralization during language production and that the increased variability of language lateralization within left-handers is characterized by the existence of rare rightward asymmetrical individuals, who in addition exhibit strong left-hand preference (Pujol et al 1999;Knecht et al 2000). Note, however, that apart from these rare individuals having reverse language lateralization, occurring with similar proportions in children and adults, handedness has no influence on the maturational increase of leftward asymmetries for language (Szaflarski et al 2011).…”

Section: Inter-individual Variability In Hs: Factors At Playmentioning

confidence: 88%

Intra- and Inter-hemispheric Connectivity Supporting Hemispheric Specialization

Tzourio‐Mazoyer

2016

Research and Perspectives in Neurosciences

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Hemispheric specialization (HS), or hemispheric dominance, is a nineteenth century concept that relates to the fact that a given hemisphere is the pilot of a given function such as, for example, the left hemisphere is dominant for language and for right-handedness. HS is grounded in both intra-hemispheric white matter connections, supported by associative bundles, and inter-hemispheric connections between cortical areas located in mirrored positions (homotopic), through the corpus callosum (CC) fiber tracts. Imaging investigations have measured anatomical and/or functional asymmetry, assessing HS at the voxelwise, regional, or hemispheric level. Comparison of these simple measures obtained with functional imaging during language tasks with results from the Wada test has validated that asymmetries do size up HS and pave the way for the investigation of HS in healthy humans. Anatomical asymmetries explain only a fraction of functional variability in lateralization, likely because structural and functional asymmetries develop at different periods of life. Anatomical asymmetries appear as early as the 26th week of gestation; at birth they are identical to those of adults. In contrast, functional neuroimaging investigations have revealed that inter-hemispheric connectivity appears at birth and is leftward asymmetrical in auditory areas, whereas in highorder language areas, this inter-hemispheric connectivity slowly shifts during development to a predominant intra-hemispheric connectivity in the adult. The precise timing and neural basis of this shift are still unknown, but it has been nevertheless shown that the connectivity is not yet in place at the age of seven and that it parallels an increase in leftward asymmetry during language tasks. Abnormal development of this asymmetry is observed in severe mental illnesses that exhibit language symptoms, such as schizophrenia and autism. In addition, after a dominant hemisphere lesion, good language capacities are associated with the recovery of a leftward asymmetry during language tasks. However, neuroimaging studies have shown that HS variability for language, up to rightward dominance, exists in healthy individuals and is partly explained by both behavioral (handedness) and anatomical (i.e., brain volume, size of the left planum temporale) factors, with these factors possibly interacting with one another. Knowledge of the setting up of N. Tzourio-Mazoyer (*)

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“…Indeed, when contrasting linguistic tasks to baseline, a bilateral pattern is often observed (Ferstl et al, 2008). Another reason might be that fMRI based lateralization indices are most often derived from a count of activated voxels in each hemisphere (Bethmann et al, 2007;Binder et al, 2000;Cai et al, 2010;Clements et al, 2006;Deppe et al, 2000;Lehéricy et al, 2000;Pujol et al, 1999;Springer et al, 1999;Szaflarski et al, 2002;Szaflarski et al, 2012;Woermann et al, 2003), a method that is very sensitive to the chosen significance threshold (Jones et al, 2011;Seghier, 2008;Suarez et al, 2009). But the divergent findings also point towards the possibility that lateralization may not be uniform across tasks and brain regions.…”

Section: Lateralization Of Broca's and Wernicke's Regions And Vwfamentioning

confidence: 99%

Lateralized task shift effects in Broca's and Wernicke's regions and in visual word form area are selective for conceptual content and reflect trial history

et al. 2014

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We investigated whether lateralized BOLD-fMRI activations in Broca's region, Wernicke's region and visual word form area (VWFA) reflect task shift costs and to which extent these effects are specific to language related task shifts. We employed a linguistic one-back memory paradigm where participants (n = 58) on each trial responded to whether a given word was the same as the previous word. In concordance with previous findings we found that conceptual shifts (CS), i.e. new words, elicited a strongly left-lateralized response in all three regions compared to repeat words. Words were sometimes presented through the visual modality (read) and sometimes through the auditory modality (spoken). This enabled the study of perceptual modality shifts (PS) relative to trials that stayed in the same modality as the previous trials. Again, we found a strongly left-lateralized effect in all regions. This was independent of whether the word was a CS or not, suggesting that linguistic translation across modalities taxes the same system as CS. Response shifts (RS), on the other hand, when shifting from one response (e.g. reporting a repeat word) to another (e.g. reporting a new word) did not yield an observable left lateralized response in any of the regions, suggesting that the lateralized task shift cost effects in these regions are not shared by all types of task shifts. Lateralization for individual tasks was found to be correlated across brain regions, but not across tasks, suggesting that lateralization may not be a unitary phenomenon, but vary across participants according to task demands. Both response time and lateralization were found to reflect the demands not only of the current trial but also of the previous trial, illustrating the context dependency of even simple cognitive tasks.

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Left-handedness and language lateralization in children

Cited by 114 publications

References 115 publications

The Importance of Orientation in Evaluating Recovery in Pediatric Traumatic Brain Injury

The Importance of Orientation in Evaluating Recovery in Pediatric Traumatic Brain Injury

Intra- and Inter-hemispheric Connectivity Supporting Hemispheric Specialization

Lateralized task shift effects in Broca's and Wernicke's regions and in visual word form area are selective for conceptual content and reflect trial history

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