Does the right hemisphere take over after damage to Broca’s area? the Barlow case of 1877 and its history

2003 ◽  
Vol 85 (3) ◽  
pp. 385-395 ◽  
Author(s):  
Stanley Finger ◽  
Randy L. Buckner ◽  
Hugh Buckingham
Keyword(s):  
Right Hemisphere ◽  
Broca’S Area ◽  
Broca's Area ◽  
The Right

scholarly journals Optical Mapping of Brain Activity Underlying Directionality and Its Modulation by Expertise in Mandarin/English Interpreting

2021 ◽  
Vol 15 ◽  
Author(s):  
Yan He ◽  
Yinying Hu ◽  
Yaxi Yang ◽  
Defeng Li ◽  
Yi Hu
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Skills ◽  
Near Infrared ◽  
Right Hemisphere ◽  
Brain Activity ◽  
Brain Regions ◽  
Broca’S Area ◽  
Broca's Area ◽  
Functional Near Infrared Spectroscopy ◽  
The Right

Recent neuroimaging research has suggested that unequal cognitive efforts exist between interpreting from language 1 (L1) to language 2 (L2) compared with interpreting from L2 to L1. However, the neural substrates that underlie this directionality effect are not yet well understood. Whether directionality is modulated by interpreting expertise also remains unknown. In this study, we recruited two groups of Mandarin (L1)/English (L2) bilingual speakers with varying levels of interpreting expertise and asked them to perform interpreting and reading tasks. Functional near-infrared spectroscopy (fNIRS) was used to collect cortical brain data for participants during each task, using 68 channels that covered the prefrontal cortex and the bilateral perisylvian regions. The interpreting-related neuroimaging data was normalized by using both L1 and L2 reading tasks, to control the function of reading and vocalization respectively. Our findings revealed the directionality effect in both groups, with forward interpreting (from L1 to L2) produced more pronounced brain activity, when normalized for reading. We also found that directionality was modulated by interpreting expertise in both normalizations. For the group with relatively high expertise, the activated brain regions included the right Broca’s area and the left premotor and supplementary motor cortex; whereas for the group with relatively low expertise, the activated brain areas covered the superior temporal gyrus, the dorsolateral prefrontal cortex (DLPFC), the Broca’s area, and visual area 3 in the right hemisphere. These findings indicated that interpreting expertise modulated brain activation, possibly because of more developed cognitive skills associated with executive functions in experienced interpreters.

scholarly journals Cortical folding in Broca's area relates to obstetric complications in schizophrenia patients and healthy controls

2011 ◽  
Vol 42 (6) ◽  
pp. 1329-1337 ◽  
Author(s):  
U. K. Haukvik ◽  
M. Schaer ◽  
R. Nesvåg ◽  
T. McNeil ◽  
C. B. Hartberg ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Three Dimensional ◽  
Obstetric Complications ◽  
Healthy Controls ◽  
Broca’S Area ◽  
Cortical Folding ◽  
Broca's Area ◽  
Control Subjects ◽  
Pars Triangularis ◽  
The Right

BackgroundThe increased occurrence of obstetric complications (OCs) in patients with schizophrenia suggests that alterations in neurodevelopment may be of importance to the aetiology of the illness. Abnormal cortical folding may reflect subtle deviation from normal neurodevelopment during the foetal or neonatal period. In the present study, we hypothesized that OCs would be related to cortical folding abnormalities in schizophrenia patients corresponding to areas where patients with schizophrenia display altered cortical folding when compared with healthy controls.MethodIn total, 54 schizophrenia patients and 54 healthy control subjects underwent clinical examination and magnetic resonance image scanning on a 1.5 T scanner. Information on OCs was collected from original birth records. An automated algorithm was used to calculate a three-dimensional local gyrification index (lGI) at numerous points across the cortical mantle.ResultsIn both schizophrenia patients and healthy controls, an increasing number of OCs was significantly related to lowerlGI in the left pars triangularis (p<0.0005) in Broca's area. For five other anatomical cortical parcellations in the left hemisphere, a similar trend was demonstrated. No significant relationships between OCs andlGI were found in the right hemisphere and there were no significant case–control differences inlGI.ConclusionsThe reduced cortical folding in the left pars triangularis, associated with OCs in both patients and control subjects suggests that the cortical effect of OCs is caused by factors shared by schizophrenia patients and healthy controls rather than factors related to schizophrenia alone.

A Functional Neuroimaging Description of Two Deep Dyslexic Patients

1998 ◽  
Vol 10 (3) ◽  
pp. 303-315 ◽  
Author(s):  
C. J. Price ◽  
D. Howard ◽  
K. Patterson ◽  
E. A. Warburton ◽  
K. J. Friston ◽  
...  
Keyword(s):  
Left Hemisphere ◽  
Word Processing ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Broca's Area ◽  
Enhanced Activity ◽  
Left Posterior ◽  
Deep Dyslexia ◽  
The Right

Deep dyslexia is a striking reading disorder that results from left-hemisphere brain damage and is characterized by semantic errors in reading single words aloud (e.g., reading spirit as whisky). Two types of explanation for this syndrome have been advanced. One is that deep dyslexia results from a residual left-hemisphere reading system that has lost the ability to pronounce a printed word without reference to meaning. The second is that deep dyslexia reflects right-hemisphere word processing. Although previous attempts to adjudicate between these hypotheses have been inconclusive, the controversy can now be addressed by mapping functional anatomy. In this study, we demonstrate that reading by two deep dyslexic patients (CJ and JG) involves normal or enhanced activity in spared left-hemisphere regions associated with naming (Broca's area and the left posterior inferior temporal cortex) and with the meanings of words (the left posterior temporo-parietal cortex and the left anterior temporal cortex). In the right-hemisphere homologues of these regions, there was inconsistent activation within the normal group and between the deep dyslexic patients. One (CJ) showed enhanced activity (relative to the normals) in the right anterior inferior temporal cortex, the other (JG) in the right Broca's area, and both in the right frontal operculum. Although these differential right-hemisphere activations may have influenced the reading behavior of the patients, their activation patterns primarily reflect semantic and phonological systems in spared regions of the left hemisphere. These results preclude an explanation of deep dyslexia in terms of purely right-hemisphere word processing.

scholarly journals Tumor location and reduction in functional MRI estimates of language laterality

2021 ◽  
pp. 1-11
Author(s):  
Monika M. Połczyńska ◽  
Lilian Beck ◽  
Taylor Kuhn ◽  
Christopher F. Benjamin ◽  
Timothy K. Ly ◽  
...  
Keyword(s):  
Functional Mri ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Tumor Location ◽  
Broca’S Area ◽  
Broca's Area ◽  
Whole Brain ◽  
Language Dominance ◽  
Left Posterior ◽  
Language Laterality

OBJECTIVE Brain tumors located close to the language cortex may distort functional MRI (fMRI)–based estimates of language dominance. The nature of this distortion, and whether this is an artifact of numerous confounders, remains unknown. The authors hypothesized tumor bias based on laterality estimates independent of confounders and that the effects are the greatest for tumors proximal to Broca's area. METHODS To answer this question, the authors reviewed more than 1113 patients who underwent preoperative fMRI to match samples on 11 known confounders (tumor location, size, type, and grade; seizure history; prior neurosurgery; aphasia presence and severity; and patient age, sex, and handedness). The samples included 30 patients with left hemisphere tumors (15 anterior and 15 posterior) and 30 with right hemisphere tumors (15 anterior and 15 posterior), thus totaling 60 patients (25 women; 18 left-handed and 4 ambidextrous; mean age 47 [SD 14.1] years). Importantly, the authors matched not only patients with left and right hemisphere tumors but also those with anterior and posterior tumors. Standard fMRI laterality indices (LIs) were calculated using whole-brain and region of interest (ROI) approaches (Broca's and Wernicke's areas). RESULTS Tumors close to Broca's area in the left hemisphere decreased LIs independently of known confounders. At the whole-brain level, this appeared to reflect a decrease in LI values in patients with left anterior tumors compared with patients with right anterior tumors. ROI analysis replicated these findings. Broca's area LIs were significantly lower (p = 0.02) in patients with left anterior tumors (mean LI 0.28) when compared with patients with right anterior tumors (mean LI 0.70). Changes in Wernicke's area–based LIs did not differ as a function of the tumor hemisphere. Therefore, in patients with left anterior tumors, it is essential to assess language laterality using left posterior ROIs. In all remaining tumor groups (left posterior tumors and right hemisphere tumors), language laterality derived from the anterior language ROI was the most robust measure of language dominance. CONCLUSIONS Patients with tumors close to Broca's area showed more bilateral fMRI language maps independent of known confounders. The authors caution against the assumption that this reduced language laterality suggests no or little risk to language function following tumor resection in the left inferior frontal gyrus. Their results address how to interpret fMRI data for neurosurgical purposes, along with theoretical questions of contralesional functional compensation and disinhibition.

Spatiotemporal Brain Activity During Hiragana Word Recognition Task

2011 ◽  
Vol 15 (3) ◽  
pp. 357-361 ◽  
Author(s):  
Hisashi Toyoshima ◽  
◽  
Takahiro Yamanoi ◽  
Toshimasa Yamazaki ◽  
Shin-ichi Ohnishi ◽  
...  
Keyword(s):  
Brain Activity ◽  
Recognition Task ◽  
Event Related Potentials ◽  
Dipole Source ◽  
Broca’S Area ◽  
Broca's Area ◽  
Current Dipole ◽  
Related Potentials ◽  
Wernicke’S Area ◽  
The Right

The 19-channel Event-Related Potentials (ERPs) we recorded during recognition of hiragana (one type of Japanese phonetic characters) were simultaneously and independently presented as a word and a nonword to opposite eyes using a field-sequential stereoscopic 3D display with a liquid-crystal shutter, a word and a non-word were simultaneously and independently presented to the left (right) and the right (left) eyes, respectively. Each word consists of 3 hiragana characters. Three subjects were instructed to press a button when they understood the meaning of the visual stimuli after 3,000 ms poststimulus. Equivalent Current Dipole source Localization (ECDL) with 3 unconstrained ECDs was applied to the ERPs. In the case of right-handed subjects, the ECDs were localized to the Wernicke’s area at around 600 ms. In the case of left-handed subject, the ECD was localized to the Wernicke’s homologue. After that ECDs were then localized to the prefrontal area, the superior frontal gyrus, and the middle frontal gyrus. At around 800 ms, the ECDs were localized to the Broca’s area, then after that ECDs were relocalized to the the Wernicke’s area and to the Broca’s area.

scholarly journals Prior Neurosurgery Decreases fMRI Estimates of Language Laterality in Patients with Gliomas within Anterior Language Sites

2021 ◽  
Vol 10 (7) ◽  
pp. 1491
Author(s):  
Monika M. Połczyńska ◽  
Bryan Ding ◽  
Bianca H. Dang ◽  
Lucia Cavanagh
Keyword(s):  
Right Hemisphere ◽  
Region Of Interest ◽  
Brain Surgery ◽  
Broca’S Area ◽  
Broca's Area ◽  
Language Dominance ◽  
Two Samples ◽  
Prior Surgery ◽  
Wernicke’S Area ◽  
The Impact

The impact of previous surgery on the assessment of language dominance with preoperative fMRI remains inconclusive in patients with recurrent brain tumors. Samples in this retrospective study included 17 patients with prior brain surgery and 21 patients without prior surgery (38 patients total; mean age 43.2, SD = 11.9; 18 females; seven left-handed). All the patients were left language dominant, as determined clinically. The two samples were matched on 10 known confounds, including, for example, tumor laterality and location (all tumors affected Brodmann areas 44/45/47). We calculated fMRI language dominance with laterality indices using a whole-brain and region of interest approach (ROI; Broca’s and Wernicke’s area). Patients with prior surgery had decreased fMRI language dominance (p = 0.03) with more activity in the right hemisphere (p = 0.03) than patients without surgery. Patients with prior brain surgery did not display less language activity in the left hemisphere than patients without surgery. These results were replicated using an ROI approach in the affected Broca’s area. Further, we observed no differences between our samples in the unaffected Wernicke’s area. In sum, prior brain surgery affecting Broca’s area could be a confounding factor that needs to be considered when evaluating fMRI language dominance.

scholarly journals Non-invasive brain stimulation as add-on therapy for subacute post-stroke aphasia: a randomized trial (NORTHSTAR)

2020 ◽  
Vol 5 (4) ◽  
pp. 402-413
Author(s):  
Anna Zumbansen ◽  
Sandra E Black ◽  
Joyce L Chen ◽  
Dylan J Edwards ◽  
Alexander Hartmann ◽  
...  
Keyword(s):  
Brain Stimulation ◽  
Interquartile Range ◽  
Secondary Outcome ◽  
Broca’S Area ◽  
Broca's Area ◽  
Sham Stimulation ◽  
Post Stroke ◽  
Non Invasive ◽  
Pars Triangularis ◽  
The Right

Introduction Non-invasive brain stimulation (NIBS) with speech therapy might improve recovery from post-stroke aphasia. This three-armed sham-controlled blinded prospective proof-of-concept study tested 1 Hz subthreshold repetitive transcranial magnetic stimulation (rTMS) and 2-mA cathodal transcranial direct current stimulation (ctDCS) on the right pars triangularis in subacute post-stroke aphasia. Patients and methods Sixty-three patients with left middle cerebral artery infarcts were recruited in five hospitals (Canada/United States/Germany, 01–2014/03–2018) and randomized to receive rTMS ( N = 20), ctDCS ( N = 24) or sham stimulation ( N = 19) with ST for 10 days. Primary outcome variables were Z-score changes in naming, semantic fluency and comprehension tests and adverse event frequency. Secondary outcome variable was the percent change in the Unified Aphasia Score. Intention-to-treat analyses tested between-group effects at days 1 and 30 post-treatment with a pre-planned subgroup analysis for lesion location (affecting Broca’s area or not). Results Naming was significantly improved by rTMS (median = 1.91/interquartile range = 0.77/ p =  .01) at 30 days versus ctDCS (median = 1.11/interquartile range = 1.51) and sham stimulation (median = 1.02/interquartile range = 1.71). All other primary results were non-significant. The rTMS effect was driven by the patient subgroup with intact Broca’s area where NIBS tended to improve UnAS (median = 33.2%/interquartile range = 46.7%/ p =  .062) versus sham stimulation (median = 12.5%/interquartile range = 7.9%) at day 30. Conversely, in patients with infarcted Broca’s area, UnAS tended to improve more with sham stimulation (median = 75.0%/interquartile range = 86.9%/ p =  .053) versus NIBS (median = 12.7%/interquartile range = 31.7). Conclusion: We found a delayed positive effect of low-frequency rTMS targeting the right pars triangularis on the recovery of naming performance in subacute post-stroke aphasia. This intervention may be beneficial only in patients with morphologically intact Broca’s area.

scholarly journals Changes of the Brain Causal Connectivity Networks in Patients With Long-Term Bilateral Hearing Loss

2021 ◽  
Vol 15 ◽  
Author(s):  
Gang Zhang ◽  
Long-Chun Xu ◽  
Min-Feng Zhang ◽  
Yue Zou ◽  
Le-Min He ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Visual Cortex ◽  
Cognitive Decline ◽  
Hearing Level ◽  
Broca’S Area ◽  
Imaging Data ◽  
Broca's Area ◽  
Dorsolateral Prefrontal ◽  
The Right

It remains poorly understood how brain causal connectivity networks change following hearing loss and their effects on cognition. In the current study, we investigated this issue. Twelve patients with long-term bilateral sensorineural hearing loss [mean age, 55.7 ± 2.0; range, 39–63 years; threshold of hearing level (HL): left ear, 49.0 ± 4.1 dB HL, range, 31.25–76.25 dB HL; right ear, 55.1 ± 7.1 dB HL, range, 35–115 dB HL; the duration of hearing loss, 16.67 ± 4.5, range, 3–55 years] and 12 matched normally hearing controls (mean age, 52.3 ± 1.8; range, 42–63 years; threshold of hearing level: left ear, 17.6 ± 1.3 dB HL, range, 11.25–26.25 dB HL; right ear, 19.7 ± 1.3 dB HL, range, 8.75–26.25 dB HL) participated in this experiment. We constructed and analyzed the causal connectivity networks based on functional magnetic resonance imaging data of these participants. Two-sample t-tests revealed significant changes of causal connections and nodal degrees in the right secondary visual cortex, associative visual cortex, right dorsolateral prefrontal cortex, left subgenual cortex, and the left cingulate cortex, as well as the shortest causal connectivity paths from the right secondary visual cortex to Broca’s area in hearing loss patients. Neuropsychological tests indicated that hearing loss patients presented significant cognitive decline. Pearson’s correlation analysis indicated that changes of nodal degrees and the shortest causal connectivity paths were significantly related with poor cognitive performances. We also found a cross-modal reorganization between associative visual cortex and auditory cortex in patients with hearing loss. Additionally, we noted that visual and auditory signals had different effects on neural activities of Broca’s area, respectively. These results suggest that changes in brain causal connectivity network are an important neuroimaging mark of cognitive decline. Our findings provide some implications for rehabilitation of hearing loss patients.

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