The Experts below are selected from a list of 1776 Experts worldwide ranked by ideXlab platform
Einar W Mencl - One of the best experts on this subject based on the ideXlab platform.
-
individual differences in reading skill are related to trial by trial neural activation variability in the reading network
The Journal of Neuroscience, 2018Co-Authors: Stephen J. Frost, Jeffrey G. Malins, Nicole Landi, Kenneth R. Pugh, Bonnie Buis, Fumiko Hoeft, Einar W MenclAbstract:Recent work has suggested that variability in levels of neural activation may be related to behavioral and cognitive performance across a number of domains and may offer information that is not captured by more traditional measures that use the average level of brain activation. We examined the relationship between reading skill in school-aged children and neural activation variability during a functional MRI reading task after taking into account average levels of activity. The reading task involved matching printed and spoken words to pictures of items. Single trial activation estimates were used to calculate the mean and standard deviation of children9s responses to print and speech stimuli; multiple regression analyses evaluated the relationship between reading skill and trial-by-trial activation variability. The reliability of observed findings from the discovery sample (n = 44; ages 8–11; 18 female) was then confirmed in an independent sample of children (n = 32; ages 8–11; 14 female). Across the two samples, reading skill was positively related to trial-by-trial variability in the activation response to print in the left inferior frontal gyrus Pars triangularis. This relationship held even when accounting for mean levels of activation. This finding suggests that intrasubject variability in trial-by-trial fMRI activation responses to printed words accounts for individual differences in human reading ability that are not fully captured by traditional mean levels of brain activity. Furthermore, this positive relationship between trial-by-trial activation variability and reading skill may provide evidence that neural variability plays a beneficial role during early reading development. SIGNIFICANCE STATEMENT Recent work has suggested that neural activation variability, or moment-to-moment changes in the engagement of brain regions, is related to individual differences in behavioral and cognitive performance across multiple domains. However, differences in neural activation variability have not yet been evaluated in relation to reading skill. In the current study, we analyzed data from two independent groups of children who performed an fMRI task involving reading and listening to words. Across both samples, reading skill was positively related to trial-by-trial variability in activation to print stimuli in the left inferior frontal gyrus Pars triangularis, even when accounting for the more conventional measure of mean levels of brain activity. This finding suggests that neural variability could be beneficial in developing readers.
Roy H Hamilton - One of the best experts on this subject based on the ideXlab platform.
-
continuous theta burst stimulation over right Pars triangularis facilitates naming abilities in chronic post stroke aphasia by enhancing phonological access
Brain and Language, 2019Co-Authors: Denise Y Harvey, Joely A Mass, Priyanka P Shahbasak, Rachel Wurzman, Olufunsho Faseyitan, Daniela Sacchetti, Laura Deloretta, Roy H HamiltonAbstract:Abstract Background Repetitive transcranial magnetic stimulation (rTMS) has been used experimentally to facilitate naming abilities in individuals with chronic post-stroke aphasia. However, little is known about how rTMS confers clinical improvement, hampering its therapeutic value. The present study investigated the characteristics of naming failure that improve following administration of continuous theta burst stimulation (cTBS)—an inhibitory form of rTMS—to the right Pars triangularis (rPTr) in persons with chronic aphasia. Methods Eleven participants with chronic aphasia following left hemisphere stroke named pictures prior to and immediately following cTBS of the rPTr and a control site (vertex) in separate sessions. Prior to stimulation, we obtained two baseline measurements of picture naming ability to determine the extent and type (i.e., phonological vs. semantic) of naming impairment. Items presented for naming during stimulation were those that were named incorrectly in one or both of the baseline sessions (i.e., inconsistent vs. wrong items, respectively). Analyses assessed whether cTBS effects differed depending on the severity and/or type of naming impairment. Results Relative to vertex, cTBS of the rPTr improved naming of inconsistent, but not wrong, items for individuals with more severe baseline naming impairment. Critically, baseline phonological but not semantic naming impairment severity marginally correlated with improved accuracy overall, and significantly correlated with decreased phonological errors following rPTr stimulation. Conclusion CTBS of the rPTr enhances naming by facilitating phonological access during word retrieval, indicating that individuals whose naming impairment is localized to this stage of processing may be most likely to benefit from this rTMS approach.
-
The right hemisphere is not unitary in its role in aphasia recovery
Cortex, 2011Co-Authors: Peter E. Turkeltaub, Olufunsho Faseyitan, H. Branch Coslett, Amy L. Thomas, Jennifer Benson, Catherine Norise, Roy H HamiltonAbstract:Abstract Neurologists and aphasiologists have debated for over a century whether right hemisphere recruitment facilitates or impedes recovery from aphasia. Here we present a well-characterized patient with sequential left and right hemisphere strokes whose case substantially informs this debate. A 72-year-old woman with chronic nonfluent aphasia was enrolled in a trial of transcranial magnetic stimulation (TMS). She underwent 10 daily sessions of inhibitory TMS to the right Pars triangularis. Brain activity was measured during picture naming using functional magnetic resonance imaging (fMRI) prior to TMS exposure and before and after TMS on the first day of treatment. Language and cognition were tested behaviorally three times prior to treatment, and at 2 and 6 months afterward. Inhibitory TMS to the right Pars triangularis induced immediate improvement in naming, which was sustained 2 months later. fMRI confirmed a local reduction in activity at the TMS target, without expected increased activity in corresponding left hemisphere areas. Three months after TMS, the patient suffered a right hemisphere ischemic stroke, resulting in worsening of aphasia without other clinical deficits. Behavioral testing 3 months later confirmed that language function was impacted more than other cognitive domains. The paradoxical effects of inhibitory TMS and the stroke to the right hemisphere demonstrate that even within a single patient, involvement of some right hemisphere areas may support recovery, while others interfere. The behavioral evidence confirms that compensatory reorganization occurred within the right hemisphere after the original stroke. No support is found for interhemispheric inhibition, the theoretical framework on which most therapeutic brain stimulation protocols for aphasia are based.
Anne L. Foundas - One of the best experts on this subject based on the ideXlab platform.
-
Broca's Area
Encyclopedia of the Neurological Sciences, 2020Co-Authors: Anne L. Foundas, T.a. Knaus, J. ShieldsAbstract:Broca's area is critical for language output. Paul Broca reported severe expressive language impairments in two patients who had a lesion in the inferior frontal gyrus (IFG). Broca's area is now defined in the IFG, specifically the Pars opercularis and Pars triangularis (Brodmann's areas 44 and 45). Language, and thus Broca's area, is strongly lateralized (both anatomically and functionally).
-
Variability in Perisylvian Brain Anatomy in Healthy Adults.
Brain and Language, 2005Co-Authors: Tracey A. Knaus, Angela M. Bollich, David M. Corey, Lisa C. Lemen, Anne L. FoundasAbstract:Abstract Gray matter volumes of Heschl’s gyrus (HG), planum temporale (PT), Pars triangularis (PTR), and Pars opercularis were measured on MRI in 48 healthy right-handers. There was the expected leftward PT asymmetry in 70.8%, and leftward PTR asymmetry in 64.6% of the sample. When asymmetry patterns within individuals were examined, there was not one typical pattern, rather several typical configurations were found. In addition, some combinations of asymmetry did not exist in our sample suggesting that some perisylvian anatomical configurations may provide a more suitable neural substrate for the development of language than others. There were also sex differences in HG. Men had rightward asymmetry and women demonstrated leftward asymmetry, due to women having smaller right HG, compared to men.
-
morphology of the frontal operculum a volumetric magnetic resonance imaging study of the Pars triangularis
Journal of Neuroimaging, 2001Co-Authors: Anne L. Foundas, Alec Weisberg, Cassandra A. Browning, Daniel R. WeinbergerAbstract:OBJECTIVE: Broca's area, which includes the Pars triangularis (PTR), is a neuroanatomical region important in speech and language production. Linear measures of the PTR have been found to be asymmetric, with the direction of the asymmetry correlating with language dominance determined by Wada testing. It is unclear, however, whether these linear measurements correlate with volumetric measures, and it is also unknown whether white matter and/or gray matter contribute differentially to these asymmetries. To investigate these issues, volumetric magnetic resonance imaging methodologies were used to measure the PTR in a group of healthy right-handed men (n = 12). There was a significant leftward asymmetry of the PTR using linear and volumetric measures. Linear measures of the left and right hemispheres were highly correlated with volumetric measures. Underlying gray and white matter both contributed to PTR asymmetry. Anatomical boundaries and four configurations (V, U, Y, and J) are discussed with reference to potential interhemispheric differences.
-
MRI Asymmetries of Broca's Area: The Pars triangularis and Pars Opercularis ☆ ☆☆
Brain and Language, 1998Co-Authors: Anne L. Foundas, Kathy F. Eure, Laura F. Luevano, Daniel R. WeinbergerAbstract:Broca's area, which includes the Pars triangularis (PTR) and Pars opercularis (POP), is a neuroanatomic region important in speech-language production. Previous data demonstrated that PTR asymmetries are highly correlated with language dominance determined by selective hemispheric anesthesia or Wada testing, suggesting that asymmetries of the PTR may, in part, predict language dominance. The POP, however, has not been measured on volumetric magnetic resonance imaging (MRI), and therefore, it is unclear whether morphological asymmetries of the POP exist, and whether these asymmetries differ in right- and left-handers. The purpose of this study was to determine if measurable asymmetries of the POP exist on MRI, and whether the direction of the asymmetries differ in right- and left-handers. The PTR and POP were measured on volumetric MRI scans of 16 right-handers and 16 left-handers matched for age and gender. There was a significant leftward asymmetry of the PTR in right- and left-handers, although the asymmetry was reduced in the left-handers. In contrast, there was a leftward asymmetry of the POP in right-handers, and a rightward asymmetry in the left-handers. Handedness, derived from a handedness inventory, was positively correlated with POP asymmetry.
-
mri asymmetries of broca s area the Pars triangularis and Pars opercularis
Brain and Language, 1998Co-Authors: Anne L. Foundas, Kathy F. Eure, Laura F. Luevano, Daniel R. WeinbergerAbstract:Broca's area, which includes the Pars triangularis (PTR) and Pars opercularis (POP), is a neuroanatomic region important in speech-language production. Previous data demonstrated that PTR asymmetries are highly correlated with language dominance determined by selective hemispheric anesthesia or Wada testing, suggesting that asymmetries of the PTR may, in part, predict language dominance. The POP, however, has not been measured on volumetric magnetic resonance imaging (MRI), and therefore, it is unclear whether morphological asymmetries of the POP exist, and whether these asymmetries differ in right- and left-handers. The purpose of this study was to determine if measurable asymmetries of the POP exist on MRI, and whether the direction of the asymmetries differ in right- and left-handers. The PTR and POP were measured on volumetric MRI scans of 16 right-handers and 16 left-handers matched for age and gender. There was a significant leftward asymmetry of the PTR in right- and left-handers, although the asymmetry was reduced in the left-handers. In contrast, there was a leftward asymmetry of the POP in right-handers, and a rightward asymmetry in the left-handers. Handedness, derived from a handedness inventory, was positively correlated with POP asymmetry.
Kenneth M Heilman - One of the best experts on this subject based on the ideXlab platform.
-
Pars triangularis asymmetry and language dominance
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Anne L. Foundas, Christiana M Leonard, Robin L Gilmore, Eileen B Fennell, Kenneth M HeilmanAbstract:Abstract The Pars triangular is a portion of Broca's area. The convolutions that form the inferior and caudal extent of the Pars triangularis include the anterior horizontal and anterior ascending rami of the sylvian fissure, respectively. To learn if there are anatomic asymmetries of the Pars triangularis, these convolutions were measured on volumetric magnetic resonance imaging scans of 11 patients who had undergone selective hemispheric anesthesia (Wada testing) to determine hemispheric speech and language lateralization. Of the 10 patients with language lateralized to the left hemisphere, 9 had a leftward asymmetry of the Pars triangularis. The 1 patient with language lateralized to the right hemisphere had a significant rightward asymmetry of the Pars triangularis. Our data suggest that asymmetries of the Pars triangularis may be related to speech-language lateralization.
-
Morphologic Cerebral Asymmetries and Handedness-Reply
JAMA Neurology, 1995Co-Authors: Anne L. Foundas, Christiana M Leonard, Kenneth M HeilmanAbstract:In reply We appreciate Goldblatt's astute observation regarding the summary of Levy and Reid's 1 findings. Furthermore, we hope to bring Goldblatt back from Matthew Arnold's darkling plain to the planum temporale and Pars triangularis. Surely, Goldblatt has not joined the armies of the ignorant, as he noted an error in the text not corrected by the authors. This sentence as written adds to the confusion of the already complex relationship of writing posture to lateralized language functions. The sentence as cited 2 should state: They found that right-handed subjects with a noninverted writing posture and left-handed subjects with an inverted writing posture had a right visual field advantage (left hemisphere dominance) on a verbal task, whereas right-handed subjects with an inverted writing posture and left-handed subjects with a noninverted writing posture had a left visual field advantage (right hemisphere dominance). Simply stated, the inference from these data is that
-
morphologic cerebral asymmetries and handedness the Pars triangularis and planum temporale
JAMA Neurology, 1995Co-Authors: Anne L. Foundas, Christiana M Leonard, Kenneth M HeilmanAbstract:Objective: To explore the relationship between morphologic cerebral asymmetries of the Pars triangularis (PTr) and the planum temporale (PT) measured on threedimensional, gradient-echo, magnetic resonance imaging scans of healthy right- and left-handed subjects. Design: (Blinded) comparison of healthy right- and left-handed subjects who underwent magnetic resonance imaging. Setting: The Seimens 1-T Magnetom (Seimens, Iselin, NH) at the University of Florida Health Science Center, Gainesville. Subjects: Healthy right-handed (n=8) and left-handed (n=8) subjects matched for age, sex, and educational level. Main Outcome Measures: (1) Average length of the PTr (anterior ascending and anterior descending rami), (2) average length of the PT, (3) asymmetry quotients {[left-right]/[(left+right) (0.5)] } of the PTr and PT, and (4) combined asymmetry quotients of the PTr and PT. Results: There was a significant leftward asymmetry of the PTr and PT in the right-handed subjects, but there was no significant asymmetry in the left-handed subjects. When the combined asymmetry quotient of the PTr and PT was calculated, the right-handed subjects had a leftward asymmetry (87.5% [n=7]) or left was equal to right (12.5% [n=1]), and the left-handed subjects had a leftward asymmetry (62.5% [n=5]), left was equal to right (12.5% [n=1]), or a rightward asymmetry (25% [n=2]). In the left-handed subjects, writing posture seemed to predict these combined asymmetry quotients, ie, left-handed subjects using an inverted writing posture had a leftward asymmetry and left-handed subjects using a noninverted writing posture had a rightward asymmetry of the perisylvian speech-language regions. Conclusions: On three-dimensional, gradient-echo, magnetic resonance imaging scans, we found a significant leftward asymmetry of the PTr and PT. When the groups were divided into right- and left-handed subjects, the former had a significant leftward asymmetry of the PTr and PT, while the latter did not. Measurements of the PTr and PT appear to be important indexes of the known functional asymmetries of the perisylvian speech-language regions.
Jeffrey G. Malins - One of the best experts on this subject based on the ideXlab platform.
-
Common neural basis of motor sequence learning and word recognition and its relation with individual differences in reading skill.
Scientific Studies of Reading, 2018Co-Authors: Yi Hui Hung, Stephen J. Frost, Peter J. Molfese, Jeffrey G. Malins, Nicole Landi, W. Einar Mencl, Jay G. Rueckl, Louisa Bogaerts, Kenneth R. PughAbstract:ABSTRACTTo investigate the neural basis of a common statistical learning mechanism involved in motor sequence learning and decoding, we recorded brain activation from participants during a serial reaction time (SRT) task and a word reading task using functional magnetic resonance imaging. In the SRT task, a manual response was made depending on the location of a visual cue, and the order of the locations was either fixed or random. In the word reading task, visual words were passively presented. In the inferior frontal gyrus Pars triangularis (IFGpTr) and the insula, differences in activation between the ordered and random condition in the SRT task and activation to printed words in the word reading task were correlated with the participants’ decoding ability. We speculate that extraction of statistically predictable patterns in the IFGpTr and insula contributes to both motor sequence learning and orthographic learning, and therefore predicts individual differences in decoding skill.
-
individual differences in reading skill are related to trial by trial neural activation variability in the reading network
The Journal of Neuroscience, 2018Co-Authors: Stephen J. Frost, Jeffrey G. Malins, Nicole Landi, Kenneth R. Pugh, Bonnie Buis, Fumiko Hoeft, Einar W MenclAbstract:Recent work has suggested that variability in levels of neural activation may be related to behavioral and cognitive performance across a number of domains and may offer information that is not captured by more traditional measures that use the average level of brain activation. We examined the relationship between reading skill in school-aged children and neural activation variability during a functional MRI reading task after taking into account average levels of activity. The reading task involved matching printed and spoken words to pictures of items. Single trial activation estimates were used to calculate the mean and standard deviation of children9s responses to print and speech stimuli; multiple regression analyses evaluated the relationship between reading skill and trial-by-trial activation variability. The reliability of observed findings from the discovery sample (n = 44; ages 8–11; 18 female) was then confirmed in an independent sample of children (n = 32; ages 8–11; 14 female). Across the two samples, reading skill was positively related to trial-by-trial variability in the activation response to print in the left inferior frontal gyrus Pars triangularis. This relationship held even when accounting for mean levels of activation. This finding suggests that intrasubject variability in trial-by-trial fMRI activation responses to printed words accounts for individual differences in human reading ability that are not fully captured by traditional mean levels of brain activity. Furthermore, this positive relationship between trial-by-trial activation variability and reading skill may provide evidence that neural variability plays a beneficial role during early reading development. SIGNIFICANCE STATEMENT Recent work has suggested that neural activation variability, or moment-to-moment changes in the engagement of brain regions, is related to individual differences in behavioral and cognitive performance across multiple domains. However, differences in neural activation variability have not yet been evaluated in relation to reading skill. In the current study, we analyzed data from two independent groups of children who performed an fMRI task involving reading and listening to words. Across both samples, reading skill was positively related to trial-by-trial variability in activation to print stimuli in the left inferior frontal gyrus Pars triangularis, even when accounting for the more conventional measure of mean levels of brain activity. This finding suggests that neural variability could be beneficial in developing readers.