scholarly journals The neurobiology of agrammatic sentence comprehension: a lesion study

2017 ◽  
Author(s):  
Corianne Rogalsky ◽  
Arianna N. LaCroix ◽  
Kuan-Hua Chen ◽  
Steven W. Anderson ◽  
Hanna Damasio ◽  
...  

AbstractBroca’s area has long been implicated in sentence comprehension. Damage to this region is thought to be the central source of “agrammatic comprehension” in which performance is substantially worse (and near chance) on sentences with noncanonical word orders compared to canonical word order sentences (in English). This claim is supported by functional neuroimaging studies demonstrating greater activation in Broca’s area for noncanonical versus canonical sentences. However, functional neuroimaging studies also have frequently implicated the anterior temporal lobe (ATL) in sentence processing more broadly, and recent lesion-symptom mapping studies have implicated the ATL and mid temporal regions in agrammatic comprehension. The present study investigates these seemingly conflicting findings in 66 left hemisphere patients with chronic focal cerebral damage. Patients completed two sentence comprehension measures, sentence-picture matching and plausibility judgments. Patients with damage including Broca’s area (but excluding the temporal lobe; n=11) on average did not exhibit the expected agrammatic comprehension pattern, e.g. their performance was > 80% on noncanonical sentences in the sentence-picture matching task. Patients with ATL damage (n=18) also did not exhibit an agrammatic comprehension pattern. Across our entire patient sample, the lesions of patients with agrammatic comprehension patterns in either task had maximal overlap in posterior superior temporal and inferior parietal regions. Using voxel-based lesion symptom mapping (VLSM), we find that lower performances on canonical and noncanonical sentences in each task are both associated with damage to a large left superior temporal-inferior parietal network including portions of the ATL, but not Broca’s area. Notably however, response bias in plausibility judgments was significantly associated with damage to inferior frontal cortex, including gray and white matter in Broca’s area, suggesting that the contribution of Broca’s area to sentence comprehension may be related to task-related cognitive demands.

2018 ◽  
Vol 30 (2) ◽  
pp. 234-255 ◽  
Author(s):  
Corianne Rogalsky ◽  
Arianna N. LaCroix ◽  
Kuan-Hua Chen ◽  
Steven W. Anderson ◽  
Hanna Damasio ◽  
...  

Broca's area has long been implicated in sentence comprehension. Damage to this region is thought to be the central source of “agrammatic comprehension” in which performance is substantially worse (and near chance) on sentences with noncanonical word orders compared with canonical word order sentences (in English). This claim is supported by functional neuroimaging studies demonstrating greater activation in Broca's area for noncanonical versus canonical sentences. However, functional neuroimaging studies also have frequently implicated the anterior temporal lobe (ATL) in sentence processing more broadly, and recent lesion–symptom mapping studies have implicated the ATL and mid temporal regions in agrammatic comprehension. This study investigates these seemingly conflicting findings in 66 left-hemisphere patients with chronic focal cerebral damage. Patients completed two sentence comprehension measures, sentence–picture matching and plausibility judgments. Patients with damage including Broca's area (but excluding the temporal lobe; n = 11) on average did not exhibit the expected agrammatic comprehension pattern—for example, their performance was >80% on noncanonical sentences in the sentence–picture matching task. Patients with ATL damage ( n = 18) also did not exhibit an agrammatic comprehension pattern. Across our entire patient sample, the lesions of patients with agrammatic comprehension patterns in either task had maximal overlap in posterior superior temporal and inferior parietal regions. Using voxel-based lesion–symptom mapping, we find that lower performances on canonical and noncanonical sentences in each task are both associated with damage to a large left superior temporal–inferior parietal network including portions of the ATL, but not Broca's area. Notably, however, response bias in plausibility judgments was significantly associated with damage to inferior frontal cortex, including gray and white matter in Broca's area, suggesting that the contribution of Broca's area to sentence comprehension may be related to task-related cognitive demands.


2006 ◽  
Vol 18 (4) ◽  
pp. 665-679 ◽  
Author(s):  
Colin Humphries ◽  
Jeffrey R. Binder ◽  
David A. Medler ◽  
Einat Liebenthal

In previous functional neuroimaging studies, left anterior temporal and temporal-parietal areas responded more strongly to sentences than to randomly ordered lists of words. The smaller response for word lists could be explained by either (1) less activation of syntactic processes due to the absence of syntactic structure in the random word lists or (2) less activation of semantic processes resulting from failure to combine the content words into a global meaning. To test these two explanations, we conducted a functional magnetic resonance imaging study in which word order and combinatorial word meaning were independently manipulated during auditory comprehension. Subjects heard six different stimuli: normal sentences, semantically incongruent sentences in which content words were randomly replaced with other content words, pseudoword sentences, and versions of these three sentence types in which word order was randomized to remove syntactic structure. Effects of syntactic structure (greater activation to sentences than to word lists) were observed in the left anterior superior temporal sulcus and left angular gyrus. Semantic effects (greater activation to semantically congruent stimuli than either incongruent or pseudoword stimuli) were seen in widespread, bilateral temporal lobe areas and the angular gyrus. Of the two regions that responded to syntactic structure, the angular gyrus showed a greater response to semantic structure, suggesting that reduced activation for word lists in this area is related to a disruption in semantic processing. The anterior temporal lobe, on the other hand, was relatively insensitive to manipulations of semantic structure, suggesting that syntactic information plays a greater role in driving activation in this area.


2009 ◽  
Vol 21 (12) ◽  
pp. 2434-2444 ◽  
Author(s):  
David January ◽  
John C. Trueswell ◽  
Sharon L. Thompson-Schill

For over a century, a link between left prefrontal cortex and language processing has been accepted, yet the precise characterization of this link remains elusive. Recent advances in both the study of sentence processing and the neuroscientific study of frontal lobe function suggest an intriguing possibility: The demands to resolve competition between incompatible characterizations of a linguistic stimulus may recruit top–down cognitive control processes mediated by prefrontal cortex. We use functional magnetic resonance imaging to test the hypothesis that individuals use shared prefrontal neural circuitry during two very different tasks—color identification under Stroop conflict and sentence comprehension under conditions of syntactic ambiguity—both of which putatively rely on cognitive control processes. We report the first demonstration of within-subject overlap in neural responses to syntactic and nonsyntactic conflict. These findings serve to clarify the role of Broca's area in, and the neural and psychological organization of, the language processing system.


2020 ◽  
Vol 32 (2) ◽  
pp. 256-271 ◽  
Author(s):  
Sigfus Kristinsson ◽  
Helga Thors ◽  
Grigori Yourganov ◽  
Sigridur Magnusdottir ◽  
Haukur Hjaltason ◽  
...  

Left-hemisphere brain damage commonly affects patients' abilities to produce and comprehend syntactic structures, a condition typically referred to as “agrammatism.” The neural correlates of agrammatism remain disputed in the literature, and distributed areas have been implicated as important predictors of performance, for example, Broca's area, anterior temporal areas, and temporo-parietal areas. We examined the association between damage to specific language-related ROIs and impaired syntactic processing in acute aphasia. We hypothesized that damage to the posterior middle temporal gyrus, and not Broca's area, would predict syntactic processing abilities. One hundred four individuals with acute aphasia (<20 days poststroke) were included in the study. Structural MRI scans were obtained, and all participants completed a 45-item sentence–picture matching task. We performed an ROI-based stepwise regression analyses to examine the relation between cortical brain damage and impaired comprehension of canonical and noncanonical sentences. Damage to the posterior middle temporal gyrus was the strongest predictor for overall task performance and performance on noncanonical sentences. Damage to the angular gyrus was the strongest predictor for performance on canonical sentences, and damage to the posterior superior temporal gyrus predicted noncanonical scores when performance on canonical sentences was included as a cofactor. Overall, our models showed that damage to temporo-parietal and posterior temporal areas was associated with impaired syntactic comprehension. Our results indicate that the temporo-parietal area is crucially implicated in complex syntactic processing, whereas the role of Broca's area may be complementary.


2020 ◽  
Author(s):  
William Matchin ◽  
Emily Wood

AbstractNeuroimaging studies of syntactic processing typically result in similar activation profiles in Broca’s area and the posterior temporal lobe (PTL). However, substantial functional dissociations between these regions have been demonstrated with respect to lesion-symptom mapping in aphasia. To account for this, Matchin & Hickok (2020) proposed that both regions play a role in syntactic processing, broadly construed, but attribute distinct functions to these regions with respect to production and comprehension. Here we report an fMRI study designed to test this hypothesis by contrasting the subvocal articulation and comprehension of structured jabberwocky phrases (syntactic), sequences of real words (lexical), and sequences of pseudowords (phonological). We defined two sets of language-selective regions of interest (ROIs) in individual subjects for Broca’s area and the PTL using the contrasts [syntactic > lexical] and [syntactic > phonological]. We found robust significant interactions of comprehension and production between these two regions at the syntactic level, for both sets of language-selective ROIs. This suggests a core difference in the function of these regions: language-selective subregions of Broca’s area play a role in syntax driven by the demands of production, whereas language-selective subregions of the PTL play a role in syntax driven by the demands of comprehension.


2011 ◽  
Vol 23 (7) ◽  
pp. 1664-1680 ◽  
Author(s):  
Corianne Rogalsky ◽  
Gregory Hickok

The role of Broca's area in sentence processing has been debated for the last 30 years. A central and still unresolved issue is whether Broca's area plays a specific role in some aspect of syntactic processing (e.g., syntactic movement, hierarchical structure building) or whether it serves a more general function on which sentence processing relies (e.g., working memory). This review examines the functional organization of Broca's area in regard to its contributions to sentence comprehension, verbal working memory, and other multimodal cognitive processes. We suggest that the data are consistent with the view that at least a portion of the contribution of Broca's area to sentence comprehension can be attributed to its role as a phonological short-term memory resource. Furthermore, our review leads us to conclude that there is no compelling evidence that there are sentence-specific processing regions within Broca's area.


Author(s):  
Margreet Vogelzang ◽  
Christiane M. Thiel ◽  
Stephanie Rosemann ◽  
Jochem W. Rieger ◽  
Esther Ruigendijk

Purpose Adults with mild-to-moderate age-related hearing loss typically exhibit issues with speech understanding, but their processing of syntactically complex sentences is not well understood. We test the hypothesis that listeners with hearing loss' difficulties with comprehension and processing of syntactically complex sentences are due to the processing of degraded input interfering with the successful processing of complex sentences. Method We performed a neuroimaging study with a sentence comprehension task, varying sentence complexity (through subject–object order and verb–arguments order) and cognitive demands (presence or absence of a secondary task) within subjects. Groups of older subjects with hearing loss ( n = 20) and age-matched normal-hearing controls ( n = 20) were tested. Results The comprehension data show effects of syntactic complexity and hearing ability, with normal-hearing controls outperforming listeners with hearing loss, seemingly more so on syntactically complex sentences. The secondary task did not influence off-line comprehension. The imaging data show effects of group, sentence complexity, and task, with listeners with hearing loss showing decreased activation in typical speech processing areas, such as the inferior frontal gyrus and superior temporal gyrus. No interactions between group, sentence complexity, and task were found in the neuroimaging data. Conclusions The results suggest that listeners with hearing loss process speech differently from their normal-hearing peers, possibly due to the increased demands of processing degraded auditory input. Increased cognitive demands by means of a secondary visual shape processing task influence neural sentence processing, but no evidence was found that it does so in a different way for listeners with hearing loss and normal-hearing listeners.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii212-ii212
Author(s):  
John Andrews ◽  
Nathan Cahn ◽  
Benjamin Speidel ◽  
Valerie Lu ◽  
Mitchel Berger ◽  
...  

Abstract Brodmann’s areas 44/45 of the inferior frontal gyrus (IFG), are the seat of Broca’s area. The Western Aphasia Battery is a commonly used language battery that diagnoses aphasias based on fluency, comprehension, naming and repetition. Broca’s aphasia is defined as low fluency (0-4/10), retained comprehension (4-10/10), and variable deficits in repetition (0-7.9/10) and naming (0-8/10). The purpose of this study was to find anatomic areas associated with Broca’s aphasia. Patients who underwent resective brain surgery in the dominant hemisphere were evaluated with standardized language batteries pre-op, POD 2, and 1-month post-op. The resection cavities were outlined to construct 3D-volumes of interest. These were aligned using an affine transformation to MNI brain space. A voxel-based lesion-symptom mapping (VLSM) algorithm determined areas associated with Broca’s aphasia when incorporated into a resection. Post-op MRIs were reviewed blindly and percent involvement of pars orbitalis, triangularis and opercularis was recorded. 287 patients had pre-op and POD 2 language evaluations and 178 had 1 month post-op language evaluation. 82/287 patients had IFG involvement in resections. Only 5/82 IFG resections led to Broca’s aphasia. 11/16 patients with Broca’s aphasia at POD 2 had no involvement of IFG in resection. 35% of IFG resections were associated with non-specific dysnomia and 36% were normal. By one-month, 76% of patients had normal speech. 80% of patients with Broca’s aphasia at POD 2 improved to normal speech at 1-month, with 20% improved to non-specific dysnomia. The most highly correlated (P&lt; 0.005) anatomic areas with Broca’s aphasia were juxta-sylvian pre- and post-central gyrus extending to supramarginal gyrus. While Broca’s area resections were rarely associated with Broca’s aphasia, juxta-sylvian pre- and post-central gyri extending to the supramarginal gyrus were statistically associated with Broca’s type aphasia when resected. These results have implications for planning resective brain surgery in these presumed eloquent brain areas.


2021 ◽  
pp. 026765832199790
Author(s):  
Anna Chrabaszcz ◽  
Elena Onischik ◽  
Olga Dragoy

This study examines the role of cross-linguistic transfer versus general processing strategy in two groups of heritage speakers ( n = 28 per group) with the same heritage language – Russian – and typologically different dominant languages: English and Estonian. A group of homeland Russian speakers ( n = 36) is tested to provide baseline comparison. Within the framework of the Competition model (MacWhinney, 2012), cross-linguistic transfer is defined as reliance on the processing cue prevalent in the heritage speaker’s dominant language (e.g. word order in English) for comprehension of heritage language. In accordance with the Isomorphic Mapping Hypothesis (O’Grady and Lee, 2005), the general processing strategy is defined in terms of isomorphism as a linear alignment between the order of the sentence constituents and the temporal sequence of events. Participants were asked to match pictures on the computer screen with auditorily presented sentences. Sentences included locative or instrumental constructions, in which two cues – word order (basic vs. inverted) and isomorphism mapping (isomorphic vs. nonisomorphic) – were fully crossed. The results revealed that (1) Russian native speakers are sensitive to isomorphism in sentence processing; (2) English-dominant heritage speakers experience dominant language transfer, as evidenced by their reliance primarily on the word order cue; (3) Estonian-dominant heritage speakers do not show significant effects of isomorphism or word order but experience significant processing costs in all conditions.


2011 ◽  
Vol 23 (10) ◽  
pp. 2632-2635 ◽  
Author(s):  
Evelina Fedorenko ◽  
Nancy Kanwisher

On the basis of their review of the literature, Rogalsky and Hickok [Rogalsky, C., & Hickok, G. The role of Broca's area in sentence comprehension. Journal of Cognitive Neuroscience, 23, 1664–1680, 2011] conclude that there is currently no strong evidence for the existence of “sentence-specific processing regions within Broca's area” (p. 1664). Their argument is based, in part, on the observation that many previous studies have failed to detect an effect in the left inferior frontal regions for contrasts between sentences and linguistically degraded control conditions (e.g., lists of unconnected words, lists of nonwords, or acoustically degraded sentence stimuli). Our data largely replicate this lack of activation in inferior frontal regions when traditional random-effects group analyses are conducted but crucially show robust activations in the same data for the same contrasts in almost every subject individually. Thus, it is the use of group analyses in studies of language processing, not the idea that sentences robustly activate frontal regions, that needs to be reconsidered. This reconsideration has important methodological and theoretical implications.


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