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The neural architecture of the language comprehension network: converging evidence from lesion and connectivity analyses.

Turken AU, Dronkers NF - Front Syst Neurosci (2011)

Bottom Line: In an earlier voxel-based lesion-symptom mapping analysis of data from aphasic patients (Dronkers et al., 2004), several brain regions in the left hemisphere were found to be critical for language comprehension: the left posterior middle temporal gyrus, the anterior part of Brodmann's area 22 in the superior temporal gyrus (anterior STG/BA22), the posterior superior temporal sulcus (STS) extending into Brodmann's area 39 (STS/BA39), the orbital part of the inferior frontal gyrus (BA47), and the middle frontal gyrus (BA46).The inferior occipito-frontal fasciculus, the arcuate fasciculus, and the middle and inferior longitudinal fasciculi, as well as transcallosal projections via the tapetum were found to be the most prominent white matter pathways bridging the regions important for language comprehension.The left MTG showed a particularly extensive structural and functional connectivity pattern which is consistent with the severity of the impairments associated with MTG lesions and which suggests a central role for this region in language comprehension.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterans Affairs Northern California Health Care System, Center for Aphasia and Related Disorders Martinez, CA, USA.

ABSTRACT
While traditional models of language comprehension have focused on the left posterior temporal cortex as the neurological basis for language comprehension, lesion and functional imaging studies indicate the involvement of an extensive network of cortical regions. However, the full extent of this network and the white matter pathways that contribute to it remain to be characterized. In an earlier voxel-based lesion-symptom mapping analysis of data from aphasic patients (Dronkers et al., 2004), several brain regions in the left hemisphere were found to be critical for language comprehension: the left posterior middle temporal gyrus, the anterior part of Brodmann's area 22 in the superior temporal gyrus (anterior STG/BA22), the posterior superior temporal sulcus (STS) extending into Brodmann's area 39 (STS/BA39), the orbital part of the inferior frontal gyrus (BA47), and the middle frontal gyrus (BA46). Here, we investigated the white matter pathways associated with these regions using diffusion tensor imaging from healthy subjects. We also used resting-state functional magnetic resonance imaging data to assess the functional connectivity profiles of these regions. Fiber tractography and functional connectivity analyses indicated that the left MTG, anterior STG/BA22, STS/BA39, and BA47 are part of a richly interconnected network that extends to additional frontal, parietal, and temporal regions in the two hemispheres. The inferior occipito-frontal fasciculus, the arcuate fasciculus, and the middle and inferior longitudinal fasciculi, as well as transcallosal projections via the tapetum were found to be the most prominent white matter pathways bridging the regions important for language comprehension. The left MTG showed a particularly extensive structural and functional connectivity pattern which is consistent with the severity of the impairments associated with MTG lesions and which suggests a central role for this region in language comprehension.

No MeSH data available.


Related in: MedlinePlus

Voxel-based lesion-symptom mapping findings for the regions critical for auditory sentence comprehension, as assessed by the CYCLE-R. The t-map is visualized on 11 slices from the DeArmond et al. (1989) brain atlas, which was used as the template for lesion reconstructions. Significant voxels from this map comprised five distinct regions, each associated with a different pattern of performance (see text). (Reprinted with permission from Dronkers et al., 2004).
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Figure 1: Voxel-based lesion-symptom mapping findings for the regions critical for auditory sentence comprehension, as assessed by the CYCLE-R. The t-map is visualized on 11 slices from the DeArmond et al. (1989) brain atlas, which was used as the template for lesion reconstructions. Significant voxels from this map comprised five distinct regions, each associated with a different pattern of performance (see text). (Reprinted with permission from Dronkers et al., 2004).

Mentions: Here, we investigated the structural and functional connectivity of the brain regions found to be critical for auditory sentence comprehension in an earlier investigation from our laboratory (Dronkers et al., 2004). Sentence comprehension is a complex function that engages many components of the language network and other brain regions that support language, such as working memory and cognitive control systems (Friederici, 2002; Dronkers et al., 2004). Thus, sentence comprehension is an ideal task for exploring the language comprehension network. In our previous investigation, auditory sentence comprehension deficits were analyzed in relation to lesion anatomy in 64 chronic stage aphasic patients who had suffered focal left hemisphere damage due to stroke. Sentence comprehension was assessed by the Curtiss-Yamada Comprehensive Language Evaluation, Receptive Language Test (CYCLE-R; Curtiss and Yamada, 1988). Lesions that significantly alter sentence comprehension performance were mapped on a standard template using voxel-based lesion-symptom mapping (VLSM, Bates et al., 2003). Subgroups of patients whose lesions encompassed each of these regions were also examined separately, using their scores on each CYCLE-R subtest, and their performance on the Western Aphasia Battery (WAB; Kertesz, 1982). Five brain regions were highlighted in this analysis as being critical for language comprehension: the MTG and underlying WM (hereafter referred to as “MTG”), the anterior superior temporal gyrus (“anterior STG/BA22”), a region including parts of the posterior superior temporal sulcus (STS) and the angular gyrus (“STS/BA39”), Brodmann's area 47 in pars orbitalis of the IFG (“BA47”), and a part of Brodmann's area 46 in the middle frontal gyrus (“BA46”; Figures 1,2).


The neural architecture of the language comprehension network: converging evidence from lesion and connectivity analyses.

Turken AU, Dronkers NF - Front Syst Neurosci (2011)

Voxel-based lesion-symptom mapping findings for the regions critical for auditory sentence comprehension, as assessed by the CYCLE-R. The t-map is visualized on 11 slices from the DeArmond et al. (1989) brain atlas, which was used as the template for lesion reconstructions. Significant voxels from this map comprised five distinct regions, each associated with a different pattern of performance (see text). (Reprinted with permission from Dronkers et al., 2004).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3039157&req=5

Figure 1: Voxel-based lesion-symptom mapping findings for the regions critical for auditory sentence comprehension, as assessed by the CYCLE-R. The t-map is visualized on 11 slices from the DeArmond et al. (1989) brain atlas, which was used as the template for lesion reconstructions. Significant voxels from this map comprised five distinct regions, each associated with a different pattern of performance (see text). (Reprinted with permission from Dronkers et al., 2004).
Mentions: Here, we investigated the structural and functional connectivity of the brain regions found to be critical for auditory sentence comprehension in an earlier investigation from our laboratory (Dronkers et al., 2004). Sentence comprehension is a complex function that engages many components of the language network and other brain regions that support language, such as working memory and cognitive control systems (Friederici, 2002; Dronkers et al., 2004). Thus, sentence comprehension is an ideal task for exploring the language comprehension network. In our previous investigation, auditory sentence comprehension deficits were analyzed in relation to lesion anatomy in 64 chronic stage aphasic patients who had suffered focal left hemisphere damage due to stroke. Sentence comprehension was assessed by the Curtiss-Yamada Comprehensive Language Evaluation, Receptive Language Test (CYCLE-R; Curtiss and Yamada, 1988). Lesions that significantly alter sentence comprehension performance were mapped on a standard template using voxel-based lesion-symptom mapping (VLSM, Bates et al., 2003). Subgroups of patients whose lesions encompassed each of these regions were also examined separately, using their scores on each CYCLE-R subtest, and their performance on the Western Aphasia Battery (WAB; Kertesz, 1982). Five brain regions were highlighted in this analysis as being critical for language comprehension: the MTG and underlying WM (hereafter referred to as “MTG”), the anterior superior temporal gyrus (“anterior STG/BA22”), a region including parts of the posterior superior temporal sulcus (STS) and the angular gyrus (“STS/BA39”), Brodmann's area 47 in pars orbitalis of the IFG (“BA47”), and a part of Brodmann's area 46 in the middle frontal gyrus (“BA46”; Figures 1,2).

Bottom Line: In an earlier voxel-based lesion-symptom mapping analysis of data from aphasic patients (Dronkers et al., 2004), several brain regions in the left hemisphere were found to be critical for language comprehension: the left posterior middle temporal gyrus, the anterior part of Brodmann's area 22 in the superior temporal gyrus (anterior STG/BA22), the posterior superior temporal sulcus (STS) extending into Brodmann's area 39 (STS/BA39), the orbital part of the inferior frontal gyrus (BA47), and the middle frontal gyrus (BA46).The inferior occipito-frontal fasciculus, the arcuate fasciculus, and the middle and inferior longitudinal fasciculi, as well as transcallosal projections via the tapetum were found to be the most prominent white matter pathways bridging the regions important for language comprehension.The left MTG showed a particularly extensive structural and functional connectivity pattern which is consistent with the severity of the impairments associated with MTG lesions and which suggests a central role for this region in language comprehension.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterans Affairs Northern California Health Care System, Center for Aphasia and Related Disorders Martinez, CA, USA.

ABSTRACT
While traditional models of language comprehension have focused on the left posterior temporal cortex as the neurological basis for language comprehension, lesion and functional imaging studies indicate the involvement of an extensive network of cortical regions. However, the full extent of this network and the white matter pathways that contribute to it remain to be characterized. In an earlier voxel-based lesion-symptom mapping analysis of data from aphasic patients (Dronkers et al., 2004), several brain regions in the left hemisphere were found to be critical for language comprehension: the left posterior middle temporal gyrus, the anterior part of Brodmann's area 22 in the superior temporal gyrus (anterior STG/BA22), the posterior superior temporal sulcus (STS) extending into Brodmann's area 39 (STS/BA39), the orbital part of the inferior frontal gyrus (BA47), and the middle frontal gyrus (BA46). Here, we investigated the white matter pathways associated with these regions using diffusion tensor imaging from healthy subjects. We also used resting-state functional magnetic resonance imaging data to assess the functional connectivity profiles of these regions. Fiber tractography and functional connectivity analyses indicated that the left MTG, anterior STG/BA22, STS/BA39, and BA47 are part of a richly interconnected network that extends to additional frontal, parietal, and temporal regions in the two hemispheres. The inferior occipito-frontal fasciculus, the arcuate fasciculus, and the middle and inferior longitudinal fasciculi, as well as transcallosal projections via the tapetum were found to be the most prominent white matter pathways bridging the regions important for language comprehension. The left MTG showed a particularly extensive structural and functional connectivity pattern which is consistent with the severity of the impairments associated with MTG lesions and which suggests a central role for this region in language comprehension.

No MeSH data available.


Related in: MedlinePlus