Visual cues and attention demand in locomotor positioning

Area of Science:

• * Human locomotion and perception
• * Visual cue utilization
• * Time-to-contact estimation

Background:

• * Locomotor positioning relies on accurately judging time-to-contact (Tc).
• * The tau strategy, based on target expansion rate, is a known method for Tc assessment.
• * Understanding visual cue usage and attentional demands is crucial for explaining locomotion control.

Purpose of the Study:

• * To investigate the visual cues utilized for estimating time-to-contact (Tc) during locomotor positioning.
• * To analyze the attentional demands associated with different visual cue strategies.
• * To explore alternative Tc assessment strategies beyond the tau method.

Main Methods:

• * An experiment involving 11 subjects walking towards a stationary target with restricted central visual cues.
• * Two target sizes were used to differentiate strategy applicability.
• * A dual-task paradigm (auditory stimuli reaction time) was employed to assess attentional load.

Main Results:

• * The tau strategy was feasible only with larger targets.
• * Braking initiation was earlier in dual-task conditions with smaller targets.
• * Increased reaction times in the secondary task indicated higher attentional demand for smaller targets.

Conclusions:

• * A strategy incorporating braking distance and walking speed is used for Tc estimation, especially with smaller targets or under dual-task conditions.
• * Different Tc assessment strategies involve distinct attentional processing levels.
• * Visual cue utilization for locomotion is adaptable based on target properties and cognitive load.