Motor Planning Sensitivity to Affective Looming Sounds Within The Peri-personal Space: An Interplay of Exogenous and Endogenous Influences
Our brain maps the space immediately surrounding the body, the peripersonal space (PPS), to sharpen sensory-motor coordination whenever an object enters it. Within PPS, past research demonstrated how several factors influence motor readiness: from exogenous factors, such as body-object distance and stimulus semantics, to endogenous traits like personality traits. Nevertheless, most paradigms rely on vision or touch, relegating hearing to a supporting role and leaving auditory-only contributions unclear. Here, we tested whether affective content and individual traits modulate motor planning for looming sounds that stop within PPS. Thirty-three adults completed three auditory-only tasks in which positive, negative, or neutral sounds halted at five simulated distances from the participants ears (0.3-0.7 m). We recorded anticipatory postural adjustments, distance estimates, affective ratings, and sensory suggestibility via a questionnaire. Motor responses were largely anticipated as sounds stopped nearer the body, while delayed and less precise for semantic (positive or negative) than neutral sounds. Higher suggestibility predicted longer and more variable premotor latencies, particularly for non-semantic sounds. These findings show that auditory cues alone engage flexible sensorimotor mechanisms within PPS, where exogenous (distance, semantics) and endogenous (suggestibility) factors jointly shape motor readiness and spatial perception.