| Abstrakt: |
Background: Eye tracking assessments in the laboratory have previously highlighted clear differences in eye movements between Parkinson's disease (PD) and healthy aging. However, laboratory-based eye movement tasks are artificial and limit the ecological validity of observed results. Eye movement tasks utilizing more naturalistic scenarios may provide more accurate insight into cognitive function but research in this area is limited. Objective: This systematic review aims to ascertain what naturalistic tasks have revealed about oculomotor deficits in PD and what this information may help us understand about the underlying sensorimotor and cognitive processes. Methods: Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a literature search of PsycInfo, Medline, Scopus, and Web of Science was conducted using predetermined search terms. Articles including both individuals with PD and healthy older adults completing eye tracking tasks involving naturalistic eye movements (e.g., reading, video-watching, unrestricted visual search) or naturalistic stimuli were included. Results: After screening, 30 studies were identified as matching the inclusion criteria. Results revealed consistent findings across tasks, including longer fixation durations and smaller saccadic amplitudes in PD compared to healthy aging. However, inconsistencies in the literature and a lack of standardization in tasks limit interpretation of these results. Conclusions: Naturalistic eye movement tasks highlight some consistent differences in eye movements between people with PD and healthy aging. However, future research should expand the current literature in this area and strive towards standardization of naturalistic tasks that can preferably be conducted remotely. Plain Language Summary: Previous studies using eye tracking in a laboratory environment have shown clear differences in eye movements between people with Parkinson's disease and healthy older adults. However, eye movements produced during lab-based tasks do not fully imitate eye movements produced during real-life situations, making findings from these studies less applicable to everyday life. Collecting eye movement data during tasks that mimic everyday activities might therefore provide more accurate information regarding cognitive ability in Parkinson's disease. We reviewed studies that explored eye movements during everyday tasks in Parkinson's disease to better understand what these studies might be able to tell us about the underlying cognitive processes involved in these tasks. 30 studies were summarized, including studies exploring eye movements during reading, real-life simulations, free viewing, and goal-oriented tasks with natural stimuli. A common finding from the reviewed studies was that Parkinson's patients fixated their gaze for longer and produced smaller eye movements when viewing the presented visual stimuli (e.g., pictures, texts). Nevertheless, it is difficult to draw firm conclusions about differences in eye movements between people with Parkinson's disease and healthy controls, as there were many inconsistent findings across the studies. These inconsistencies could be attributed to differences in how the tasks were designed and the types of data collected. We therefore encourage researchers in this field to work towards improving the designs of these tasks to allow for easier comparisons, ideally producing tasks that can be conducted remotely to allow for large quantities of data collection. [ABSTRACT FROM AUTHOR] |
