Portable eyetracking-based assessment of memory decline

ABSTRACT

Introduction: Preferential viewing of novel stimuli in the Visual Paired Comparison task has provided a useful marker of memory and medial temporal lobe function. We created a portable version of the VPC (P-VPC) and contrasted P-VPC metrics against the Montreal Cognitive Assessment (MoCA) in healthy adults, to assess the validity and reliability of the P-VPC as an indicator of memory function across age. A supplementary case series was conducted with individuals diagnosed with Alzheimer’s disease (AD) and other dementias, to provide a preliminary illustration of the P-VPC’s use as a measure in clinical populations.

Method: Participants (n = 207) were tested using the P-VPC. Individuals were familiarized with a set of objects, which were each presented alongside a novel object in the test phase. Novelty viewing scores were compared to MoCA scores to index concurrent validity. Item analyses were conducted as a test of internal reliability of the P-VPC. A complementary clinical case series was conducted with AD (n = 4) and dementia (n = 5) participants, who were tested using the P-VPC and further compared to healthy age-matched participants.

Results: Preferential viewing decreased with age in healthy participants, and was positively correlated with MoCA scores. Compared to the MoCA, P-VPC scores did not differ based on education and/or whether English was spoken as the native language. Item analyses revealed acceptable internal consistency. P-VPC viewing percentiles of healthy participants were modeled as a function of age, and illustrated that individuals of the clinical case series diagnosed with AD scored in below-average percentiles, while those with dementia did not score below-average.

Conclusion: Good concurrent validity and acceptable internal reliability were observed, and P-VPC scores were not confounded by education or language experience. Low performance was observed in individuals with clinically diagnosed AD, suggesting that the P-VPC may be a potential tool for screening memory decline.

KEYWORDS:

• Alzheimer’s disease
• dementia
• eyetracking
• memory
• visual paired comparison task

Acknowledgments

We would like to thank Arber Karcollja, Liuting Xu, Maria D’Angelo, Renante Rondina, and Jordana Wynn for their assistance during the testing sessions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Canadian Institutes of Health Research [grant number MOP-126003]; Ontario Centres of Excellence [grant number OCE-IACP 2013]; and the Canadian Research Chairs Foundation [grant number 483090-15630, awarded to J. D. Ryan].