von Hopffgarten Anna, Bremmer Frank
Department of Neurophysics, Philipps-University Marburg, Karl-von-Frisch-Str. 8a, 35043 Marburg, Germany.
Seeing Perceiving. 2011;24(3):203-22. doi: 10.1163/187847511X571005.
Successful locomotion through space requires precise estimation of the direction and distance travelled. Previous studies have shown that humans can use velocity information arising from visual, vestibular and somatosensory signals to reproduce passive linear displacements. In the present study we investigated whether also associated auditory velocity cues are used for distance estimation. Subjects had to reproduce (active condition) the distance of a previously seen sequence of simulated linear motion (passive condition) across a ground plane. During both, the passive and active displacement, they heard a tone with a frequency being proportional to the simulated speed (test trials). In some trials the relationship between optical velocity and tone frequency was differently scaled during the active displacements, i.e., the frequency of the tone was either higher or lower than in the passive displacement (catch trials). In test trials, subjects reproduced distances quite accurately. In catch trials, however, subjects' performance was disturbed: when the frequency was lower subjects used higher speeds, resulting in a substantial overshoot of travelled distance, whereas a higher frequency resulted in an undershoot of travelled distance. Our results clearly show that during self-motion tone frequency can be used as a velocity cue and helps to update positional information over time.
在空间中成功移动需要精确估计移动的方向和距离。先前的研究表明，人类可以利用视觉、前庭和体感信号产生的速度信息来重现被动线性位移。在本研究中，我们调查了相关的听觉速度线索是否也用于距离估计。受试者必须重现（主动条件）先前看到的在地面平面上模拟线性运动序列（被动条件）的距离。在被动和主动位移过程中，他们都听到一个频率与模拟速度成正比的音调（测试试验）。在一些试验中，在主动位移过程中，视速度与音调频率之间的关系按不同比例缩放，即音调频率在主动位移中要么高于要么低于被动位移中的频率（捕捉试验）。在测试试验中，受试者相当准确地重现了距离。然而，在捕捉试验中，受试者的表现受到干扰：当频率较低时，受试者使用较高的速度，导致行进距离大幅超调，而较高的频率则导致行进距离欠调。我们的结果清楚地表明，在自我运动过程中，音调频率可以用作速度线索，并有助于随时间更新位置信息。
