Spiousas Ignacio, Vergara Ramiro O, Lombera Esteban N, Etchemendy Pablo E
Laboratorio Interdisciplinario del Tiempo y la Experiencia (LITERA), CONICET, Universidad de San Andrés, Buenos Aires, Argentina.
Laboratorio de Acústica y Percepción Sonora, CONICET, Universidad Nacional de Quilmes, Buenos Aires, Argentina.
Atten Percept Psychophys. 2025 Jun 5. doi: 10.3758/s13414-025-03071-0.
The region of space immediately surrounding the body, where we can interact with the outside world using our limbs, is commonly known as the peripersonal space (PPS). The representation of this region in the brain is dynamic and can be influenced by kinematic properties of the stimulus such as speed and direction. It has been shown that visual or auditory approaching objects expand the observer's PPS, supporting the hypothesis of an anticipation mechanism that prioritizes approaching stimuli to better react to potential threats. However, the response to receding stimuli is not so well understood. Here, we studied the auditory PPS for approaching and receding sound sources that traveled at different speeds. In each trial, the source was presented at a fixed distance and listeners judged whether it was within arm's reach. In the next trial, the source could be presented either closer or farther, creating the impression of a discrete approaching or receding trajectory. We found that reachability judgments were affected by the previous positions of the sound source. Approaching sources were judged more reachable at the same position than receding ones while non-defined trajectories (control) displayed intermediate values, suggesting an expansion of the auditory PPS for approaching sounds. Interestingly, receding sources were judged less reachable than controls after accounting for speed, suggesting compression of the auditory PPS. This result is consistent with the idea that reachability judgments arise from an impact prediction mechanism. The implications of this idea for our understanding of PPS are discussed.
身体周围可直接与外界互动的空间区域，即我们能够用肢体与之交互的区域，通常被称为个人周边空间（PPS）。大脑中该区域的表征是动态的，并且会受到刺激的运动学特性（如速度和方向）的影响。研究表明，视觉或听觉上接近的物体可扩展观察者的个人周边空间，这支持了一种预期机制的假设，即优先处理接近的刺激，以便更好地应对潜在威胁。然而，对于后退刺激的反应，我们了解得并不那么透彻。在此，我们研究了以不同速度靠近和远离的声源的听觉个人周边空间。在每次试验中，声源在固定距离呈现，听众判断其是否在手臂可触及范围内。在下一次试验中，声源可以更近或更远地呈现，营造出离散的靠近或远离轨迹的印象。我们发现，可触及性判断受声源先前位置的影响。在相同位置，接近的声源比后退的声源被判断为更易触及，而未定义轨迹（对照组）显示出中间值，这表明接近声音的听觉个人周边空间有所扩展。有趣的是，在考虑速度后，后退声源比对照组被判断为更难触及，这表明听觉个人周边空间被压缩。这一结果与可触及性判断源于影响预测机制的观点一致。我们讨论了这一观点对我们理解个人周边空间的意义。
