A Bifurcation in Visually-Guided Behavior when Following a Crowd
A Bifurcation in Visually-Guided Behavior when Following a Crowd
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跟随人群时视觉引导行为的分歧
DOI：
10.1167/jov.22.14.4317
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发表时间：
2022
影响因子：
1.8
通讯作者：
Wirth, Trenton
中科院分区：
文献类型：
--
作者：
Warren, William;Wirth, Trenton
人类“群集”的模型表明，当每个人对邻居的速度进行加权平均时，集体运动就会出现（Rio，Dachner & Warren，PRSB，2018）。但是，当一群人分成两组，朝着不同的方向前进时，一个人会怎么做？Wirth & Warren（FAMS，2021）发现，各组之间的平均航向差异高达40。在这里，我们探索了更大范围的航向差异（0-120），并观察到从平均到跟随一组的突然转变。参与者（N= 6）被指示在佩戴无线头戴式显示器（101 H X 105 V，90 Hz）的同时与虚拟人群“一起行走”。2- 3秒后，50%的人群向左转，50%的人群向右转一个相等的角度;组间的航向差异被操纵（0，20，30，40，... 90，120）。小组成员随机穿插，形成两个连续交叉的流动。记录参与者的行走轨迹，并测量每次试验最后2s期间的最终航向。参与者沿着人群的平均方向行走，直到60岁，在那里出现分叉。概率密度函数适合于从单峰（在50 ° C时，EMBIC = 8.23）切换到双峰（在60 ° C时，EMBIC = 2.37;在70 ° C时，EMBIC = 21.69）的数据，其中两种模式接近两组的航向方向。我们通过修改Rio，et al. S（2018）模型，因此个体被吸引到±30而不是±90之间的相邻方向。在分散的鱼群中已经报道了类似的分叉（Couzin等人，2005年）。这些行为的分叉暗示了在耦合振荡器系统中观察到的相变（Kelso，1995; Mirollo & Strogatz，1990; Nabet，伦纳德，Couzin & Simon，2009）。我们接下来计划测试转变点周围的滞后现象，这是非线性相变的标志。
Models of human ‘flocking’show that collective motion emerges when each individual takes a weighted average of neighbor velocities (Rio, Dachner & Warren, PRSB, 2018). But when a crowd splits into two groups heading in different directions, what does an individual do? Wirth & Warren (FAMS, 2021) found robust averaging up to a heading difference of 40 between groups. Here we explore a larger range of heading differences (0-120) and observe a sudden transition from averaging to following one group. Participants (N= 6) were instructed to “walk with” a virtual crowd while wearing a wireless head-mounted display (101 H x 105 V, 90 Hz). After 2-3s, 50% of the crowd turned left and 50% turned an equal angle to the right; the heading difference between groups was manipulated (0, 20, 30, 40,… 90, 120). Group members were randomly interspersed and formed two continuously crossing flows. The participant’s walking trajectory was recorded, and final heading during the last 2s of each trial was measured. Participants walked in the mean direction of the crowd until 60, where a bifurcation occurred. Probability density functions fit to the data switched from unimodal (∆ BIC= 8.23 at 50) to bimodal (∆ BIC= 2.37 at 60;∆ BIC= 21.69 at 70), with the two modes close to the heading directions of the two groups. We simulated the data by modifying Rio, et al.’s (2018) model so an individual is attracted to neighbor headings between±30 rather than±90. A similar bifurcation has been reported in diverging fish schools (Couzin, et al., 2005). These bifurcations in behavior are suggestive of phase transitions observed in systems of coupled oscillators (Kelso, 1995; Mirollo & Strogatz, 1990; Nabet, Leonard, Couzin & Simon, 2009). We next plan to test for hysteresis around the transition point, a signature of nonlinear phase transitions.