Woodley Christa M, Urbanczyk Aaron C, Smith David L, Lemasson Bertrand H
Cognitive Ecology & Ecohydraulics Team, Environmental Laboratory, US Army Engineer Research and Development Center.
Cognitive Ecology & Ecohydraulics Team, Environmental Laboratory, US Army Engineer Research and Development Center;
J Vis Exp. 2019 May 2(147). doi: 10.3791/59281.
Collective animal behavior arises from individual motivations and social interactions that are critical for individual fitness. Fish have long inspired investigations into collective motion, specifically, their ability to integrate environmental and social information across ecological contexts. This demonstration illustrates techniques used for quantifying behavioral responses of fish, in this case, Golden Shiner (Notemigonus crysoleucas), to visual stimuli using computer visualization and digital image analysis. Recent advancements in computer visualization allow for empirical testing in the lab where visual features can be controlled and finely manipulated to isolate the mechanisms of social interactions. The purpose of this method is to isolate visual features that can influence the directional decisions of the individual, whether solitary or with groups. This protocol provides specifics on the physical Y-maze domain, recording equipment, settings and calibrations of the projector and animation, experimental steps and data analyses. These techniques demonstrate that computer animation can elicit biologically-meaningful responses. Moreover, the techniques are easily adaptable to test alternative hypotheses, domains, and species for a broad range of experimental applications. The use of virtual stimuli allows for the reduction and replacement of the number of live animals required, and consequently reduces laboratory overhead. This demonstration tests the hypothesis that small relative differences in the movement speeds (2 body lengths per second) of virtual conspecifics will improve the speed and accuracy with which shiners follow the directional cues provided by the virtual silhouettes. Results show that shiners directional decisions are significantly affected by increases in the speed of the visual cues, even in the presence of background noise (67% image coherency). In the absence of any motion cues, subjects chose their directions at random. The relationship between decision speed and cue speed was variable and increases in cue speed had a modestly disproportionate influence on directional accuracy.
群体动物行为源于对个体适应性至关重要的个体动机和社会互动。长期以来，鱼类一直激发着人们对群体运动的研究，特别是它们在不同生态环境中整合环境和社会信息的能力。本演示展示了用于量化鱼类行为反应的技术，在本案例中是金色闪光鱼（Notemigonus crysoleucas）对视觉刺激的行为反应，使用计算机可视化和数字图像分析。计算机可视化的最新进展使得在实验室中进行实证测试成为可能，在实验室中可以控制和精细操纵视觉特征以分离社会互动的机制。该方法的目的是分离出能够影响个体（无论是单独还是群体）方向决策的视觉特征。本方案提供了关于物理Y迷宫区域、记录设备、投影仪和动画的设置与校准、实验步骤以及数据分析的详细信息。这些技术表明计算机动画可以引发具有生物学意义的反应。此外，这些技术很容易适应测试各种实验应用中的替代假设、区域和物种。虚拟刺激的使用减少并替代了所需活体动物的数量，从而降低了实验室成本。本演示测试了这样一个假设，即虚拟同种个体运动速度的微小相对差异（每秒2个体长）将提高闪光鱼跟随虚拟轮廓提供的方向线索的速度和准确性。结果表明，即使存在背景噪声（67%的图像连贯性），视觉线索速度的增加也会显著影响闪光鱼的方向决策。在没有任何运动线索的情况下，受试者随机选择方向。决策速度和线索速度之间的关系是可变的，线索速度的增加对方向准确性有适度不成比例的影响。
