A novel video-based paradigm to study the mechanisms underlying age- and falls risk-related differences in gaze behaviour during walking.

Abstract

The current study aimed to quantitatively assess differences in gaze behaviour between participants grouped on the basis of their age and measures of functional mobility during a virtual walking paradigm. The gaze behaviour of nine young adults, seven older adults with a relatively low risk of falling and seven older adults with a relatively higher risk of falling was measured while they watched five first-person perspective movies representing the viewpoint of a pedestrian walking through various environments. Participants also completed a number of cognitive tests: Stroop task, visual search, trail making task, Mini Mental Status Examination, and reaction time, visual tests (visual acuity and contrast sensitivity) and assessments of balance (Activities Balance Confidence Scale and Berg Balance Scale) to aid in the interpretation of differences in gaze behaviour. The high risk older adult group spent significantly more time fixating aspects of the travel path than the low risk and young adult groups. High risk older adults were also significantly slower in performing a number of the cognitive tasks than young adults. Correlations were conducted to compare the extent to which travel path fixation durations co-varied with scores on the tests of visual search, motor, and cognitive function. A positive significant correlation was found between the speed of response to the incongruent Stroop task and travel path fixation duration r21 =0.44, p<0.05. The results indicate that our movie-viewing paradigm can identify differences in gaze behaviour between participants grouped on the basis of their age and measures of functional mobility and that these differences are associated with cognitive decline.