Lesion analysis of the brain areas involved in language comprehension

Abstract

The cortical regions of the brain traditionally associated with the comprehension of language are Wernicke's area and Broca's area. However, recent evidence suggests that other brain regions might also be involved in this complex process. This paper describes the opportunity to evaluate a large number of brain-injured patients to determine which lesioned brain areas might affect language comprehension. Sixty-four chronic left hemisphere stroke patients were evaluated on 11 subtests of the Curtiss-Yamada Comprehensive Language Evaluation - Receptive (CYCLE-R; Curtiss, S., & Yamada, J. (1988). Curtiss-Yamada Comprehensive Language Evaluation. Unpublished test, UCLA). Eight right hemisphere stroke patients and 15 neurologically normal older controls also participated. Patients were required to select a single line drawing from an array of three or four choices that best depicted the content of an auditorily-presented sentence. Patients' lesions obtained from structural neuroimaging were reconstructed onto templates and entered into a voxel-based lesion-symptom mapping (VLSM; Bates, E., Wilson, S., Saygin, A. P., Dick, F., Sereno, M., Knight, R. T., & Dronkers, N. F. (2003). Voxel-based lesion-symptom mapping. Nature Neuroscience, 6(5), 448-450.) analysis along with the behavioral data. VLSM is a brain-behavior mapping technique that evaluates the relationships between areas of injury and behavioral performance in all patients on a voxel-by-voxel basis, similar to the analysis of functional neuroimaging data. Results indicated that lesions to five left hemisphere brain regions affected performance on the CYCLE-R, including the posterior middle temporal gyrus and underlying white matter, the anterior superior temporal gyrus, the superior temporal sulcus and angular gyrus, mid-frontal cortex in Brodmann's area 46, and Brodmann's area 47 of the inferior frontal gyrus. Lesions to Broca's and Wernicke's areas were not found to significantly alter language comprehension on this particular measure. Further analysis suggested that the middle temporal gyrus may be more important for comprehension at the word level, while the other regions may play a greater role at the level of the sentence. These results are consistent with those seen in recent functional neuroimaging studies and offer complementary data in the effort to understand the brain areas underlying language comprehension.

Functional neuroimaging of word priming in males with chronic schizophrenia

“…Previous studies from our laboratory also found that the posterior superior temporal region showed decreased volume that correlated with thought disorder (Shenton et al, 1992) and abnormal fMRI activity in response to visual words that correlated with levels of positive symptoms in schizophrenic subjects (Kubicki et al, 2003). The middle temporal gyrus has been shown in lesion, stimulation, and neuroimaging studies to be the neural substrate for semantic comprehension at the single word level (Indefry & Levelt, 2000;Boatman, 2004;Bates et al, 2003;Dronkers et al, 2004;Hart & Gordon, 1990). For example, in a study of 101 patients with left hemisphere damage, comprehension was most affected by damage to the middle temporal gyrus (Bates et al, 2003; and see also Dronkers et al, 2004).…”

“…Distractive speech, in addition to correlating with abnormal activation in the middle temporal region, correlated with a small region of left inferior prefrontal cortex. This region (~BA 47) is thought to subserve working memory for semantic features and thematic structure, and may be used to re-analyze and repair utterance (Dronkers et al, 2004). Abnormal activity in this region might impair the ability of patients to use thematic structure and context to constrain their utterances.…”

“…The middle temporal gyrus has been shown in lesion, stimulation, and neuroimaging studies to be the neural substrate for semantic comprehension at the single word level (Indefry & Levelt, 2000;Boatman, 2004;Bates et al, 2003;Dronkers et al, 2004;Hart & Gordon, 1990). For example, in a study of 101 patients with left hemisphere damage, comprehension was most affected by damage to the middle temporal gyrus (Bates et al, 2003; and see also Dronkers et al, 2004). This region contains either semantic representations or the link between semantic representations and lexical representations.…”

Dissociation in the neural basis underlying Chinese tone and vowel production

“…The left middle temporal gyrus (BA37) is believed to be important for word-level comprehension, especially as the ties between the concepts and corresponding lexical representations (Dronkers et al, 2004). Like posterior cingulated gyrus discussed above, for the pinyin-naming task, the hippocampal gyrus is also related to verbal and auditory memory (Milner, 1974).…”

Thresholding lesion overlap difference maps: Application to category-related naming and recognition deficits

“…lesion overlap, lesion difference, lesion proportion, etc.) summarizing lesion-deficit associations, with the purpose of identifying the region(s) critical for the support of a particular function (Cancelliere and Kertesz, 1990;Damasio et al, 1996;Tranel et al, 1997;Barrash et al, 2000;Haaland et al, 2000;Adolphs et al, 2002;Dronkers et al, 2004;Heberlein et al, 2004). The region of maximal lesion overlap/difference is related to the deficit and typically hypothesized to be critical for the normal function.…”