The effect of age-related macular degeneration on cognitive test performance

Anne Macnamara,Tobias Loetscher,Celia Chen,Scott Coussens,Victor R Schinazi

doi:10.1038/s41598-022-07924-8

Abstract

The reliable assessment of cognitive functioning is critical to the study of brain-behaviour relationships. Yet conditions that are synchronous which ageing, including visual decline, are easily overlooked when interpreting cognitive test scores. The purpose of this study was to demonstrate the negative consequences of visual impairments on cognitive tests performance. Moderate to severe levels of age-related macular degeneration were simulated, with a set of goggles, in a sample of twenty-four normally sighted participants while they completed two cognitive tasks: a vision-dependent reaction time task and a vision-independent verbal fluency test. Performance on the reaction time task significantly decreased (p < 0.001) in the simulated age-related macular degeneration condition, by as much as 25 percentile ranks. In contrast, performance on the verbal fluency test were not statistically different between the simulated and normal vision conditions (p = 0.78). The findings highlight the importance of considering visual functioning when assessing cognitive function. When vision is not accounted for, low test scores may inaccurately indicate poor cognition. Such false attributions may have significant ramification for diagnosis and research on cognitive functioning.

Highlights

The reliable assessment of cognitive functioning is critical to the study of brain-behaviour relationships
One leading cause of visual impairment is age-related macular degeneration (AMD), which may result in an irreversible loss of central v ision[5]; and can negatively impact tasks involving visual functioning including reading, driving and recognising faces[6]
For the Reaction Time Task (RTI), mental response times significantly increased in the simulated AMD condition (381.98, SD = 29.90 ms) compared to the normal vision condition (359.02, SD = 28.04 ms; see Fig. 3), (F(1,22) = 31.66, p < 0.001, n2p = 0.59)

Summary

Introduction

The reliable assessment of cognitive functioning is critical to the study of brain-behaviour relationships. Moderate to severe levels of age-related macular degeneration were simulated, with a set of goggles, in a sample of twenty-four normally sighted participants while they completed two cognitive tasks: a vision-dependent reaction time task and a vision-independent verbal fluency test. Cognitive tests scores inform research and diagnoses in aging and neurodegenerative disorders These scores can be impacted by a range of factors not directly measured by tests, ranging from situational, personal, language to cultural factors[1]. One leading cause of visual impairment is age-related macular degeneration (AMD), which may result in an irreversible loss of central v ision[5]; and can negatively impact tasks involving visual functioning including reading, driving and recognising faces[6]. To highlight the importance of central vision for cognitive assessments, we simulated visual impairment with AMD simulation goggles, while participants completed a series of cognitive tasks. AMD simulations have replicated patterns of behaviour and difficulties experienced by AMD p atients[9]

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Conclusion