Anxiety and inhibition impact people's walking direction

Introduction: Healthy individuals display a tendency to allocate attention unequally across space, and this bias has implications for how individuals interact with their environments. However, the origins of this phenomenon remain relatively poorly understood. The present research examined the joint and independent contributions of two fundamental motivational systems – behavioral approach and inhibition systems (BAS and BIS) – to lateral spatial bias in a locomotion task. Activation of BAS is linked to the experience of positive affect and goal-directed behavior. In contrast, activation of BIS is linked to the experience of anxiety, increased sensitivity to threatening cues, and disruption of ongoing processes. Methods: Seventy-eight participants completed self-report measures of trait BAS and BIS, then repeatedly traversed a room, blindfolded, aiming for a straight line. We obtained locomotion data from motion tracking to capture variations in participants’ walking trajectories. Results: Overall, walking trajectories deviated to the left, and this tendency was more pronounced with increasing BIS scores. Meanwhile, BAS was associated with relative rightward tendencies when BIS was low, but not when BIS was high. Conclusions: These results demonstrate for the first time an association between BIS (implicated in anxiety) and lateral spatial bias independently of variations in BAS (implicated in positive affect). We discuss the implications of these findings for the neurobiological underpinnings of BIS and for the treatment of unilateral neglect - a condition caused by a lack of awareness of one side of space.