Training-induced improvement of noncanonical sentence production does not generalize to comprehension: evidence for modality-specific processes

Abstract

The presence or absence of generalization after treatment can provide important insights into the functional relationship between cognitive processes. The aim of the present study was to investigate the relationship between the cognitive processes that underlie sentence comprehension and production in aphasia. Using data from seven participants who took part in a case-series intervention study that focused on noncanonical sentence production [Stadie et al. (2008). Unambiguous generalization effects after treatment of noncanonical sentence production in German agrammatism. Brain and Language, 104, 211–229], we identified patterns of impairments and generalization effects for the two modalities. Results showed (a) dissociations between sentence structures and modalities before treatment, (b) an absence of cross-modal generalization from production to comprehension after treatment, and (c), a co-occurrence of spared comprehension before treatment and generalization across sentence structures within production after treatment. These findings are in line with the assumption of modality-specific, but interacting, cognitive processes in sentence comprehension and production. More specifically, this interaction is assumed to be unidirectional, allowing treatment-induced improvements in production to be supported by preserved comprehension.

Keywords:

• sentence production
• sentence comprehension
• cross-modal generalization
• aphasia treatment
• syntactic processing of noncanonical sentences

Acknowledgements

We would like to thank Lyndsey Nickels, Saskia Kohnen, and three anonymous reviewers for their comments on earlier versions of the manuscript. We are grateful to the seven participants with aphasia for their participation in the study and to Stefanie Münn, Karoline Schlichting, and Ilka Wörz for collecting the control data reported.

Additional information

Funding

The intervention study was supported by the Federal Ministry of Education and Research (BMBF) [grant number 01GA01001], “A cross-linguistic study of syntactic disorders in aphasia: From theory to therapy” and was carried out together with Ria De Bleser, Antje Lorenz, Jenny von Frankenberg, and Maria Swoboda-Moll.