Locomotion and eye behaviour under controlled environment in individuals with Alzheimer's disease

Abstract

This study aimed to examine simple locomotion and eye behaviour of individuals with Posterior Cortical Atrophy (PCA) and typical Alzheimer's disease (tAD) within a simulated real-world environment. Posterior cortical atrophy (PCA) is a neurodegenerative condition characterised by parietal, occipital and occipito-temporal tissue loss and progressive impairment of higher-order visual function in contrast to relatively spared memory and language. Targeted types of locomotion were walking in a series of corridors, up or down stairs, and across an open room with or without the presence of an obstacle. Eye tracking measures and inertial moment units (IMU) were used in this experiment, and resultant acceleration of left foot and fixation duration were extracted. Findings from three participants are presented as a case series: one control, one PCA and one tAD patient. The averaged resultant acceleration of PCA patient was the slowest in all types of locomotion, especially in stairs. The averaged resultant accelerations of PCA and tAD participants were slower than the control participant. The PCA participant had longer mean fixation durations than the tAD and control participants, however, mean fixation duration was similar between tAD and control participants. Results may help characterise locomotion and eye behaviour in PCA and tAD and may suggest ways to support effective diagnosis and assessment of disease progression.

The Potential of Naturalistic Eye Movement Tasks in the Diagnosis of Alzheimer’s Disease: A Review

“…More advanced AD was associated with orientation to lower visual space. Similarly, Suzuki et al [ 83 ] found that the durations of fixations across all of the locomotion tasks (e.g., walking through corridors, walking up or down stairs, walking through a room with or without an obstacle) did not significantly differ between the AD patient and HOC.…”

“…Five [ 25 , 46 , 51 , 64 , 83 ] of the studies included here analysed eye movements during real-life simulations. Specifically, two of such studies analysed eye movement behaviours during every-day tasks [ 25 , 51 ], and the remaining two employed tasks that simulated real-life situations.…”

“…A quality assessment of all of the included papers revealed that the majority of papers suffered from a moderate risk of bias (score rating: 15–20; [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 46 , 47 , 48 , 49 , 51 , 52 , 63 , 64 , 65 , 66 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 81 , 82 , 84 , 85 ]), with two receiving a particularly high risk of bias score (score rating: 0–14; [ 25 , 45 , 80 , 83 ]). Here, bias refers to factors that can systematically affect the observations and conclusions of a study [ 94 ].…”

“…Resultantly, 39 papers passed through full-text screening and were identified as being relevant to our research question [ 25 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 ].…”

Computational Techniques for Eye Movements Analysis towards Supporting Early Diagnosis of Alzheimer’s Disease: A Review

“…In addition, the PwAD showed a lower proportion of relevant fixations compared to control subjects. In the work by Suzuki et al [ 28 ] eye movement is investigated during locomotion. One AD patient, one Posterior Cortical Atrophy (PCA) patient, and one healthy subject used an eye tracking device while performing locomotion activities (walking along corridors, up and down stairs, and across a room with or without obstacles).…”