Harvard Medical School, Boston, MA, USA.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Brigham Hospital, Boston, MA, USA.
Sci Rep. 2021 Oct 25;11(1):20960. doi: 10.1038/s41598-021-99578-1.
Personal space has been defined as "the area individuals maintain around themselves into which others cannot intrude without arousing discomfort". However, the precise relationship between discomfort (or arousal) responses as a function of distance from an observer remains incompletely understood. Also the mechanisms involved in recognizing conspecifics and distinguishing them from other objects within personal space have not been identified. Accordingly, here we measured personal space preferences in response to real humans and human-like avatars (in virtual reality), using well-validated "stop distance" procedures. Based on threshold measurements of personal space, we examined within-subject variations in discomfort-related responses across multiple distances (spanning inside and outside each individual's personal space boundary), as reflected by psychological (ratings) and physiological (skin conductance) responses to both humans and avatars. We found that the discomfort-by-distance functions for both humans and avatars were closely fit by a power law. These results suggest that the brain computation of visually-defined personal space begins with a 'rough sketch' stage, which generates responses to a broad range of human-like stimuli, in addition to humans. Analogous processing mechanisms may underlie other brain functions which respond similarly to both real and simulated human body parts.
个人空间被定义为“个体自身周围的区域，他人未经允许进入会引起不适”。然而，对于距离观察者的距离与不适感（或觉醒）反应之间的精确关系，仍不完全了解。此外，在个人空间内识别同种个体并将其与其他物体区分开来的机制也尚未确定。因此，我们在这里使用经过充分验证的“停止距离”程序，测量了对真实人类和类人头像（虚拟现实）的个人空间偏好。基于个人空间的阈值测量，我们在多个距离（跨越每个人的个人空间边界的内部和外部）上检查了与不适感相关的反应的个体内变化，这些变化反映在对人类和头像的心理（评分）和生理（皮肤电导率）反应上。我们发现，人类和头像的不适感-距离函数都可以用幂律很好地拟合。这些结果表明，大脑对视觉定义的个人空间的计算始于一个“粗略草图”阶段，该阶段除了人类之外，还会对广泛的类人刺激产生反应。类似的处理机制可能是其他对真实和模拟人体部位有类似反应的大脑功能的基础。
