The effect of repetition on pronoun resolution in patients with memory impairment

ABSTRACT

Referring to things in the world – that woman, her idea, she – is a central component of language. Understanding reference requires the listener to keep track of the unfolding discourse history while integrating multiple sources of information to interpret the speech stream as it unfolds in time. Pronouns are a common way to establish reference. But due to their impoverished form, to understand them listeners must relate features of the pronoun (e.g., gender, animacy) with existing representations of potential discourse referents. Successful referential processing seems to place demands on memory. In a previous study, patients with hippocampal amnesia and healthy participants listened to short stories as their eye movements were monitored. When interpreting ambiguous pronouns, healthy participants demonstrated order-of-mention effects, whereby ambiguous pronouns are interpreted as referring to the first-mentioned referent in the story. By contrast, memory-impaired patients exhibited significant disruptions in their ability to use information about which character had been mentioned first to interpret pronouns. Repetition of the most salient information is a common clinical recommendation for improving pronoun resolution and communication in individuals with memory disorders (e.g., Alzheimer’s disease) but this recommendation lacks an evidentiary basis. The present study seeks to determine whether the pronoun resolution performance of hippocampal patients can be improved, by repetition of the target referent, increasing its salience. Results indicate that patients with hippocampal damage demonstrate improved processing of pronouns following repetition of the target referent, but benefit from this repetition to a significantly smaller degree compared to healthy participants. These results provide further evidence for the role of the hippocampal-dependent memory system in language processing and point to the need for empirically tested communication interventions.

KEYWORDS:

• Memory
• language
• hippocampus
• comprehension
• rehabilitation

Acknowledgments

The authors thank Sharice Clough for her help in data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

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Notes

1. LogRatioTC was chosen as the dependent variable to maintain consistency with the previous study (Kurczek et al., 2013). However, LogRatioTC has been noted to be non-normally distributed. Therefore, following Ryskin, et al. (2015), a supplemental analysis used a binary dependent variable, with 1 = target fixation during the trial; 0 = no target fixation. The results of this analysis were equivalent to the LogRatioTC analysis and are reported in Table 5. In addition, model-predicted probabilities of target fixations in the critical region of analysis are presented in Table 6.

Additional information

Funding

Funding Details: This work was supported by NIDCD grant R01 DC011755 to MCD and SBS.