The effects of temporal pressure on obstacle negotiation and gaze behaviour in young adults with simulated vision loss

Abstract

Individuals with vision loss adapt their locomotion and gaze behaviour to safely negotiate objects in temporally unconstrained situations. However, everyday activities are often performed under timepressure. We investigated the effects of blur on anxiety, movement kinematics and gaze behaviour during the negotiation of a floor-based obstacle under three amounts of pressure: 1) no-pressure; 2) tonal-pressure: an intermittent tone was played at a constant frequency; 3) tonal + time pressure: the intermittent tone increased in frequency and participants had to walk 20% faster to reach the end of the lab. Irrespective of the amount of pressure, the blurred vs. normal vision group reported 32% more anxiety, lifted the lead foot 43% higher and 10% slower over the obstacle, and looked 6% longer and 6% more frequently ahead of the obstacle. In the tonal + time pressure vs. no-pressure condition, both groups were more anxious, showed adaptations in movement kinematics related to walking faster, and adopted a 'checking strategy' by shortening their fixation durations at the obstacle. These results show that irrespective of temporal pressure, the blurred vision group remained more cautious as to how the lead foot negotiated the obstacle, in order to reduce the chance of tripping during crossing.

Children With Developmental Coordination Disorder Exhibit Greater Stepping Error Despite Similar Gaze Patterns and State Anxiety Levels to Their Typically Developing Peers

“…Consequently, work is still needed to determine the extent to which gaze and stepping performance might be altered in the presence of heightened anxiety. To achieve this, researchers could explore time-pressure and/or dual-task situations as they have both been shown to induce anxiety (Uemura et al, 2012;Zult et al, 2019) and exacerbate motor difficulties in children with DCD (Wilson and McKenzie, 1998). Alternatively, researchers could explore ecologically valid tasks in which the cost of falling is much greater, such as when walking up and down a staircase.…”

The effects of age and central field loss on maintaining balance control when stepping up to a new level under time-pressure

“…Toe-off was defined as the instant where the resultant velocity of the foot’s toe marker first increased more than 0.9 m/s for ten consecutive frames ( Zult et al, 2019 ). Participants’ initial contact with the force plate was either with the heel or forefoot.…”

“…Participants’ initial contact with the force plate was either with the heel or forefoot. Heel strike was defined as the instant when the resultant velocity of the foot’s medial heel marker first decreased less than 0.6 m/s for ten consecutive frames ( Zult et al, 2019 ). Toe strike was defined as the instant when the resultant velocity of the foot’s toe marker first decreased less than 0.2 m/s for ten consecutive frames.…”

“…The results of this analysis will be published alongside this article because the current article focuses on the ‘step-up to a new level’ task. The included kinematic variables for obstacle negotiation are similar to a previous article that investigated the effects of time-pressure in participants with (simulated) vision loss ( Zult et al, 2019 ).…”

Furthering Visual Accessibility with Extended Reality (XR): A Systematic Review

“…Simulations are a valuable experimental tool for studying performance in tasks such as visual search [1,47,83], face perception [63,99], reading [45,58], and navigation [7,32,121]. While a blindfold is the easiest way to simulate impairment for a sighted participant, it is limited due to the instant removal of all visual information.…”