WSAB — Worn-Shoe Assumption Bias

Trips over footwear left on the floor are common minor domestic accidents. Traditional explanations attribute such events to divided attention, reduced visual scanning, and environmental clutter. This paper proposes a novel cognitive hypothesis: individuals may subconsciously maintain an embodied representation of footwear as being worn, resulting in reduced perceptual salience when encountering detached shoes in the walking path. This phenomenon, termed the Worn-Shoe Assumption Bias (WSAB), is grounded in predictive processing theory and embodied cognition research. We argue that habitual integration of shoes into the body schema may transiently suppress obstacle classification when footwear appears in atypical spatial configurations. The paper outlines theoretical foundations, testable predictions, and experimental paradigms for empirical evaluation.

01 Introduction

The Neglected Hazard

Among the catalogue of minor domestic injuries, the shoe-trip occupies a peculiar position: ubiquitous, faintly comedic, and poorly understood. Emergency department records consistently document lacerations, sprains, and fractures attributable to encounters with footwear placed on walking surfaces. Yet the cognitive mechanisms underlying this failure of obstacle detection have received scant empirical attention.

Prevailing accounts invoke general inattention or visual field occlusion. We contend these explanations are incomplete. The shoe is not merely an overlooked object — it is an object with a privileged and habitual relationship to the observer's own body.

02 Theoretical Framework

Predictive Processing & the Body Schema WSAB

Predictive processing frameworks hold that perception is fundamentally a process of hypothesis testing: the brain generates top-down predictions and updates them with sensory evidence (Clark, 2016; Friston, 2010). Objects with highly stable, context-bound predictions generate reduced prediction errors and consequently attract less attentional weighting.

Shoes occupy an unusual ecological niche. For the majority of waking hours in indoor-outdoor environments, footwear occupies a predictable spatial configuration: affixed to the feet. This habitual association plausibly generates a strong prior — a standing prediction that shoes are worn.

When shoes are encountered in a detached floor configuration, the body schema's standing prediction of footwear-as-worn transiently suppresses their classification as traversable obstacles, reducing perceptual salience and elevating trip probability.

Embodied cognition research supports the notion that tools and worn objects become integrated into the peripersonal body schema (Maravita & Iriki, 2004). We propose that this integration is persistent enough to generate residual priors even when the footwear is no longer worn — particularly in domestic environments where habitual wearing and removal follow strong temporal rhythms.

03 Cognitive Mechanism

Schema Integration Cascade

Body Schema Encoding — Repeated shoe-wearing integrates footwear into peripersonal space representation

Prior Formation — Brain assigns high probability to shoes-as-worn state; floor configuration becomes low-probability prediction

Prediction Error Suppression — Detached floor shoe triggers weak mismatch signal; obstacle salience is attenuated

Motor Planning Failure — Walking trajectory computed without obstacle avoidance; trip event occurs

The transient suppression is hypothesised to decay rapidly once physical contact is initiated (i.e., the foot catches the shoe), consistent with the sharp, surprising quality of the trip experience commonly reported.

04 Testable Predictions

Experimental Paradigms

Ownership Effect. Participants will exhibit longer obstacle detection latencies for their own shoes placed on a floor compared to unfamiliar shoes or geometrically matched non-shoe objects, controlling for size and colour.

Wear Duration Modulation. Individuals who have worn a given pair of shoes for a longer cumulative duration will show greater WSAB magnitude, as measured by detection latency and gaze dwell-time in pedestrian hazard paradigms.

Environmental Context Specificity. The suppression effect will be stronger in habitual shoe-removal environments (home hallways) compared to neutral contexts (laboratory corridors), reflecting context-dependent prior activation.

Proprioceptive Prime Reversal. Directing participants to attend to barefoot sensation immediately prior to a visual detection task will reduce WSAB magnitude, via deactivation of the shoe-integrated body schema.

Gaze Divergence. Eye-tracking will reveal reduced fixation count and shorter total dwell time on own-shoes-on-floor relative to matched objects, consistent with attenuated prediction error driving attentional capture.

05 Discussion

Implications & Limitations

If the WSAB hypothesis is supported empirically, it carries modest but meaningful practical implications. Domestic safety interventions have typically focused on visibility (contrasting shoe colours, lighting) or storage (designated shoe racks). Our framework suggests an additional lever: proprioceptive reminders or brief attentional prompts to the barefoot state may transiently release the standing prior and restore normal obstacle salience.

Several alternative explanations must be ruled out. The effect may simply reflect reduced novelty for familiar objects rather than schema-specific suppression. Longitudinal repeated measures designs with body schema manipulation conditions will be essential to discriminate these accounts.

We acknowledge that the WSAB as formulated remains a theoretical construct. The paper is intended as a framework for directed empirical inquiry rather than a report of established findings.

Fig. 1 — WSAB Event Sequence (animated)

Fig. 2 — Predictive Suppression in Body Schema

Animation depicts the hypothesised temporal sequence of a WSAB event. Both figures represent the same individual — walking confidently (WSAB active) and initiating trip (schema mismatch onset). Shoe hazard shown approximately to scale.