Comprehension of reversible constructions in semantic aphasia

Abstract

Background: Impairments in spatial processing show themselves not only in gnosis and praxis, but also in the language domain. Such deficit is a characteristic feature of so-called semantic aphasia. The impaired comprehension of semantically reversible constructions in those patients can be explained by a disorder of the common spatial neuropsychological factor grounded in the temporal-parietal-occipital (TPO) regions of the brain.

Aims: The aim of the present study was to experimentally test the possibility that individuals with semantic aphasia experience specific difficulties in extracting spatial relations from a linguistic form and rely instead on basic sensorimotor stereotypes to interpret reversible linguistic constructions.

Methods & Procedures: Six individuals with semantic aphasia, 12 people with motor aphasia, 12 people with sensory aphasia, and 12 non-brain-damaged individuals performed a sentence–picture matching task; all participants were native speakers of Russian. Two types of reversible sentences were tested, each representing a direct and an inverted word order: prepositional (The boy is putting the bag in the box vs. The boy is putting in the box the bag) and instrumental (The grandmother is covering the scarf with the hat vs. The grandmother is covering with the hat the scarf). Irreversible sentences (The boy is putting the apple in the bag) served as control stimuli.

Outcomes & Results: Each group of participants performed better on irreversible than on reversible sentences. Within reversible sentences, an interaction between word order and construction type was found in individuals with semantic aphasia only. They performed more accurately in prepositional constructions with direct word order and in instrumental constructions with inverted word order—both are related to sensorimotor stereotypes reflecting interaction with objects in the real world. Although no such clear dissociation was found in other aphasia types, correlation analysis revealed the same effect in some participants with motor and sensory aphasia.

Conclusions: The findings confirm the importance of situational context for linguistic processing. First, if knowledge of the real world supports the unique interpretation of grammatical markers, it enhances processing in all tested cohorts of participants. Second, people with semantic aphasia consistently use sensorimotor stereotypes to compensate for their linguistic deficits. Since this was also found in some participants with other aphasia types, such a sensorimotor strategy might depend not on the damage to TPO areas as such, but on the intactness and overuse of left premotor regions suggested to be critical for motor and symbolic sequential processing.

Keywords:

• semantic aphasia
• reversible sentences
• spatial relations
• sensorimotor stereotype
• Russian language

Acknowledgements

The authors are thankful to all participants of the study with and without aphasia, to Victor M. Shklovsky, the Scientific Director of the Center for Speech Pathology and Neurorehabilitation (Moscow, Russia), who inspired the undertaken investigation, and to Victor K. Dragoy who designed pictorial stimuli for the study. Special gratitude goes to Tatyana V. Akhutina, a student and a colleague of A.R. Luria in the past, for insightful discussions of the data. We also thank Kelly Callahan for careful proofreading of the manuscript and the two anonymous reviewers for their thoughtful suggestions.

Notes

1. Luria’s aphasia classification allows to diagnose a combination of several aphasia syndromes.

Additional information

Funding

This article was prepared within the framework of the Basic Research Program at the National Research University Higher School of Economics (HSE) and supported by a subsidy granted to the HSE by the Government of the Russian Federation for the implementation of the Global Competitiveness Program.