Krysiak Magdalena E, Bankieris Kaitlyn R, Abid Qura, Kui Guan Hua, Rodman Hillary R
Department of Psychology, Atlanta, GA 30322, USA.
Behav Processes. 2011 Nov;88(3):135-41. doi: 10.1016/j.beproc.2011.08.008. Epub 2011 Sep 9.
Tests of rodent visual capacities are typically performed under standard laboratory illumination. However, light level can have subtle and complex effects on behavior in rodents. We tested Mongolian gerbils (Meriones unguiculatus) - a species that shows individual differences in activity pattern - on visual tasks at three ecologically relevant levels of ambient illuminance: approximating moonlight (1 lx), dawn or dusk (10 lx), and low daylight (100 lx). A jumping task and a grating discrimination quantified depth perception and grating acuity, respectively. Illuminance variations had important effects on behavior. Gerbils jumped faster in lower light on the depth discrimination task, but were also less accurate than in bright light. Daytime activity levels (possibly reflecting variations in activity pattern) mediated these effects, with animals that were awake during a lower proportion of daytime hours exhibiting a trend toward jumping faster with lower light level as compared to more day-active gerbils. Moreover, while illuminance did not affect acuity overall, it interacted with activity levels in a complex way: in both the darkest and lowest light levels, animals that were awake during a greater proportion of daytime hours showed higher acuity levels than animals that were less active during the day. These results indicate that gerbils show behavioral profiles in vision tasks that represent an interaction between visual ability and illuminance-sensitive motivational or emotional actors, perhaps including chronotype. Thus, the most ecologically relevant assessments of the visual performance of rodents will likely be achieved by testing at species-specific preferred light levels.
对啮齿动物视觉能力的测试通常在标准实验室光照条件下进行。然而，光照水平可能会对啮齿动物的行为产生微妙而复杂的影响。我们在三种与生态相关的环境光照强度水平下，对长爪沙鼠（Meriones unguiculatus）——一种在活动模式上表现出个体差异的物种——进行了视觉任务测试：近似月光（1勒克斯）、黎明或黄昏（10勒克斯）以及低日光（100勒克斯）。一项跳跃任务和一项光栅辨别任务分别量化了深度感知和光栅敏锐度。光照强度变化对行为有重要影响。在深度辨别任务中，沙鼠在较暗光线条件下跳跃速度更快，但准确性也低于明亮光线条件下。白天的活动水平（可能反映活动模式的变化）介导了这些影响，与白天活动较多的沙鼠相比，白天清醒时间比例较低的动物呈现出随着光照水平降低跳跃速度加快的趋势。此外，虽然光照强度总体上不影响敏锐度，但它与活动水平以复杂的方式相互作用：在最暗和最低光照水平下，白天清醒时间比例较高的动物比白天活动较少的动物表现出更高的敏锐度水平。这些结果表明，沙鼠在视觉任务中表现出的行为特征代表了视觉能力与对光照敏感的动机或情绪因素（可能包括生物钟类型）之间的相互作用。因此，对啮齿动物视觉表现进行最符合生态相关性的评估可能需要在物种特定的偏好光照水平下进行测试。
