Development of an eye-tracking method to assess mental set switching in people with aphasia

ABSTRACT

Background: Deficits in cognitive flexibility contribute to impaired functional communication in people with aphasia. Understanding the relationship between functional communication and cognitive flexibility in people with neurologic communication disorders is important. However, traditional methods to assess mental set switching pose significant linguistic, cognitive and motoric response confounds. Eye-tracking methods have great potential to address these challenges.

Aims: The goal of this study was to develop and validate an eye-tracking method to index mental set switching in individuals without neurological impairment based upon performance on a nonlinguistic switching task.

Methods: Eye movements of 20 adults without communication disorders were recorded as they completed a switching task, requiring participants to match stimuli to one or two search criteria (colour or shape) in single- and mixed-task conditions. Differences between single and mixed conditions were assessed with eye-tracking measures. Performance on the eye-tracking task was compared to standardized measures of cognitive flexibility.

Results: Eye-tracking measures indexed significant differences between nonswitch and switch trials within and between single- and mixed-task condition. Some standardized assessment measures correlated significantly with the eye movement measures.

Conclusions: Results support the construct validity of the novel eye-tracking method for assessing cognitive switching in language-normal adults. Clinical and research implications are discussed.

Keywords:

• cognitive flexibility
• assessment
• executive functions
• eye tracking;
• aphasia

Acknowledgments

The authors extend their gratitude to Dr Wendy Huddleston and Dr Carol Seery, for their invaluable suggestions regarding study design, task development and data analysis. They thank Urszula Julien and Candice Hackbarth for their assistance with data extraction.

Declaration of Interest

This work was supported in part by a Student Research Grant Award by the College of Health Sciences of the University of Wisconsin-Milwaukee, awarded to the second author.