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The anterior temporal lobes support residual comprehension in Wernicke's aphasia.

Robson H, Zahn R, Keidel JL, Binney RJ, Sage K, Lambon Ralph MA - Brain (2014)

Bottom Line: Whole brain and region of interest analysis in Wernicke's aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally.Semantic processing of written words in Wernicke's aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments.Overall, the results provide support for models in which the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions.

View Article: PubMed Central - PubMed

Affiliation: 1 Neuroscience and Aphasia Research Unit, School Psychological Sciences, University of Manchester, UK.

ABSTRACT
Wernicke's aphasia occurs after a stroke to classical language comprehension regions in the left temporoparietal cortex. Consequently, auditory-verbal comprehension is significantly impaired in Wernicke's aphasia but the capacity to comprehend visually presented materials (written words and pictures) is partially spared. This study used functional magnetic resonance imaging to investigate the neural basis of written word and picture semantic processing in Wernicke's aphasia, with the wider aim of examining how the semantic system is altered after damage to the classical comprehension regions. Twelve participants with chronic Wernicke's aphasia and 12 control participants performed semantic animate-inanimate judgements and a visual height judgement baseline task. Whole brain and region of interest analysis in Wernicke's aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally. The Wernicke's aphasia group displayed an 'over-activation' in comparison with control participants, indicating that anterior temporal lobe regions become increasingly influential following reduction in posterior semantic resources. Semantic processing of written words in Wernicke's aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments. Overall, the results provide support for models in which the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions.

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Related in: MedlinePlus

Region of interest analyses. Graphs display mean beta values for each group in each region of interest. Patients with Wernicke’s aphasia (WA) demonstrated significant activation for picture and written word semantic decisions in the anterior fusiform gyrus and ventral occipital-temporal lobe bilaterally and in the left lateral polar region. Written word decision produced additionally significant results in the right anterior superior temporal gyri/sulci. aFuG = anterior fusiform gyrus; aSTG = anterior superior temporal gyrus; TP = temporal pole; vOT = ventral occipital-temporal lobe; iFrG = inferior frontal gyrus. *P < 0.05, one sample t-test.
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awt373-F3: Region of interest analyses. Graphs display mean beta values for each group in each region of interest. Patients with Wernicke’s aphasia (WA) demonstrated significant activation for picture and written word semantic decisions in the anterior fusiform gyrus and ventral occipital-temporal lobe bilaterally and in the left lateral polar region. Written word decision produced additionally significant results in the right anterior superior temporal gyri/sulci. aFuG = anterior fusiform gyrus; aSTG = anterior superior temporal gyrus; TP = temporal pole; vOT = ventral occipital-temporal lobe; iFrG = inferior frontal gyrus. *P < 0.05, one sample t-test.

Mentions: The region of interest analysis (Fig. 3) showed a very similar pattern of results. One tailed one-sample t-tests found that control participants significantly activated the left anterior fusiform gyrus for picture semantic judgements [t(11) = 3.1, P = 0.005] and the left anterior superior temporal gyri/sulci for written word judgements [t(11) = 1.9, P = 0.037]. The Wernicke’s aphasia group showed significant activation for both picture and word conditions in the left anterior fusiform gyrus [pictures: t(11) = 2.8, P = 0.009, words: t(11) = 2.0, P = 0.034], the right anterior fusiform gyrus [pictures: t(11) = 2.9, P = 0.008; words: t(11) = 1.9, P = 0.04], left temporal pole [pictures: t(11) = 2.0, P = 0.034; words: t(11) = 1.9, 0.04] and the left ventral occipital-temporal lobe [pictures: t(11) = 3.6, P = 0.004; words: t(11) = 2.8, P = 0.017]. The Wernicke’s aphasia group displayed additional activation in the right anterior superior temporal gyrus/sulcus for word stimuli [t(11) = 2.27, P = 0.022] and in the right ventral occipital-temporal lobe for the picture stimuli [t(11) = 3.5, P = 0.005]. Removal of the participants who performed at chance for the picture or written word judgements made no change to significance with the exception that significant activation was additionally found in the right temporal pole for the picture judgements [t(9) = 2.1, P = 0.03]. A ANOVA (2 × 2) revealed main effects of group in the left ventral occipital-temporal lobe [F(1,22) = 10.14, P = 0.004], right ventral occipital-temporal lobe [F(1,22) = 5.81, P = 0.025] and left temporal pole [F(1,22) = 4.65, P = 0.042] caused by significantly greater semantic activation in the Wernicke’s aphasia group than in the control group. There were no significant effects of condition or significant interactions.Figure 3


The anterior temporal lobes support residual comprehension in Wernicke's aphasia.

Robson H, Zahn R, Keidel JL, Binney RJ, Sage K, Lambon Ralph MA - Brain (2014)

Region of interest analyses. Graphs display mean beta values for each group in each region of interest. Patients with Wernicke’s aphasia (WA) demonstrated significant activation for picture and written word semantic decisions in the anterior fusiform gyrus and ventral occipital-temporal lobe bilaterally and in the left lateral polar region. Written word decision produced additionally significant results in the right anterior superior temporal gyri/sulci. aFuG = anterior fusiform gyrus; aSTG = anterior superior temporal gyrus; TP = temporal pole; vOT = ventral occipital-temporal lobe; iFrG = inferior frontal gyrus. *P < 0.05, one sample t-test.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3927705&req=5

awt373-F3: Region of interest analyses. Graphs display mean beta values for each group in each region of interest. Patients with Wernicke’s aphasia (WA) demonstrated significant activation for picture and written word semantic decisions in the anterior fusiform gyrus and ventral occipital-temporal lobe bilaterally and in the left lateral polar region. Written word decision produced additionally significant results in the right anterior superior temporal gyri/sulci. aFuG = anterior fusiform gyrus; aSTG = anterior superior temporal gyrus; TP = temporal pole; vOT = ventral occipital-temporal lobe; iFrG = inferior frontal gyrus. *P < 0.05, one sample t-test.
Mentions: The region of interest analysis (Fig. 3) showed a very similar pattern of results. One tailed one-sample t-tests found that control participants significantly activated the left anterior fusiform gyrus for picture semantic judgements [t(11) = 3.1, P = 0.005] and the left anterior superior temporal gyri/sulci for written word judgements [t(11) = 1.9, P = 0.037]. The Wernicke’s aphasia group showed significant activation for both picture and word conditions in the left anterior fusiform gyrus [pictures: t(11) = 2.8, P = 0.009, words: t(11) = 2.0, P = 0.034], the right anterior fusiform gyrus [pictures: t(11) = 2.9, P = 0.008; words: t(11) = 1.9, P = 0.04], left temporal pole [pictures: t(11) = 2.0, P = 0.034; words: t(11) = 1.9, 0.04] and the left ventral occipital-temporal lobe [pictures: t(11) = 3.6, P = 0.004; words: t(11) = 2.8, P = 0.017]. The Wernicke’s aphasia group displayed additional activation in the right anterior superior temporal gyrus/sulcus for word stimuli [t(11) = 2.27, P = 0.022] and in the right ventral occipital-temporal lobe for the picture stimuli [t(11) = 3.5, P = 0.005]. Removal of the participants who performed at chance for the picture or written word judgements made no change to significance with the exception that significant activation was additionally found in the right temporal pole for the picture judgements [t(9) = 2.1, P = 0.03]. A ANOVA (2 × 2) revealed main effects of group in the left ventral occipital-temporal lobe [F(1,22) = 10.14, P = 0.004], right ventral occipital-temporal lobe [F(1,22) = 5.81, P = 0.025] and left temporal pole [F(1,22) = 4.65, P = 0.042] caused by significantly greater semantic activation in the Wernicke’s aphasia group than in the control group. There were no significant effects of condition or significant interactions.Figure 3

Bottom Line: Whole brain and region of interest analysis in Wernicke's aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally.Semantic processing of written words in Wernicke's aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments.Overall, the results provide support for models in which the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions.

View Article: PubMed Central - PubMed

Affiliation: 1 Neuroscience and Aphasia Research Unit, School Psychological Sciences, University of Manchester, UK.

ABSTRACT
Wernicke's aphasia occurs after a stroke to classical language comprehension regions in the left temporoparietal cortex. Consequently, auditory-verbal comprehension is significantly impaired in Wernicke's aphasia but the capacity to comprehend visually presented materials (written words and pictures) is partially spared. This study used functional magnetic resonance imaging to investigate the neural basis of written word and picture semantic processing in Wernicke's aphasia, with the wider aim of examining how the semantic system is altered after damage to the classical comprehension regions. Twelve participants with chronic Wernicke's aphasia and 12 control participants performed semantic animate-inanimate judgements and a visual height judgement baseline task. Whole brain and region of interest analysis in Wernicke's aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally. The Wernicke's aphasia group displayed an 'over-activation' in comparison with control participants, indicating that anterior temporal lobe regions become increasingly influential following reduction in posterior semantic resources. Semantic processing of written words in Wernicke's aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments. Overall, the results provide support for models in which the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions.

Show MeSH
Related in: MedlinePlus