Conditional and future tense impairment in non-fluent aphasia

Abstract

Background: Morphological errors of tense and agreement are salient in agrammatic aphasia. The PADILIH predicts impairments in discourse linking that translate to greater difficulties in referring to a past event time than to a future or a present event time. In Catalan, the Periphrastic conditional tense (e.g., “if the man had had time, he would have…”) refers to the past and the Simple conditional tense refers to the future (e.g., “if the man had time, he would…”). These two tenses refer to an event that may happen (irrealis).

Aims: We fill in the gap of the conditional tense and provide further data to study contrasts in verb inflection for time reference. We predict that verb forms that refer to an irrealis past event (Periphrastic conditional) are more impaired than forms that refer to an irrealis future event (Simple conditional and Future). We also predict that there are no differences between verb forms that refer to an irrealis future event (Simple conditional and Future). We also assessed whether problems in time reference extend to individuals with non-fluent aphasia that are not typical agrammatic Broca aphasia.

Methods & Procedures: A sentence completion task that included 60 sentences (20 per type) of equal length in a Conditional structure (if-sentences) was designed. We tested three sentence types: Periphrastic conditional, Simple conditional and Future. The task was administered to nine participants with non-fluent aphasia and nine age-matched non-brain-damaged participants.

Outcomes & Results: The Control group scored at ceiling on the three sentence types. Participants with non-fluent aphasia were most impaired in the production of the Periphrastic conditional as compared with the Simple conditional and the Future.

Conclusions: When irrealis event times are compared, past events are more impaired than future events. These results can be explained by a deficit in time reference as predicted by the PADILIH. Our data reveal that the predictions of the PADILIH also hold for non-fluent speakers who have been diagnosed with Transcortical motor aphasia.

Keywords:

• Time reference
• Conditional tense
• Future tense
• Realis
• Irrealis
• Non-fluent aphasia
• Catalan
• PADILIH

The authors thank the Association Sant Pau of Language Disorders of Barcelona, José Luis Cardona, the speech and language therapists who provided the diagnostic information of the participants, Io Salmons and the participants of the study. We sincerely thank the European Masters in Clinical Linguistics and the Erasmus Mundus PhD Programme International Doctorate for Experimental Approaches to Language And Brain. One of the researchers acknowledges funding from the project FFI2010-20634 from the Spanish Ministry and the research grant Beatriu de Pinós from the Catalan Government and the project FFI2010-20634 (Micinn). We want to express our gratitude to Kelly Callahan, Vânia de Aguiar, Seth Levine and to the reviewers for their comments on an earlier version the paper.