Active Touch Laboratory, Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
Conservation, Evolution and Behaviour Research Group, Division of Biology and Conservation Ecology, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK.
Curr Biol. 2014 Jul 7;24(13):1507-12. doi: 10.1016/j.cub.2014.05.036. Epub 2014 Jun 19.
During exploration, rats and other small mammals make rhythmic back-and-forth sweeps of their long facial whiskers (macrovibrissae) [1-3]. These "whisking" movements are modulated by head movement [4] and by vibrissal sensory input [5, 6] and hence are often considered "active" in the Gibsonian sense of being purposive and information seeking [7, 8]. An important hallmark of active sensing is the modification of the control strategy according to context [9]. Using a task in which rats were trained to run circuits for food, we tested the hypothesis that whisker control, as measured by high-speed videography, changes with contextual variables such as environment familiarity, risk of collision, and availability of visual cues. In novel environments, functionally blind rats moved at slow speeds and performed broad whisker sweeps. With greater familiarity, however, they moved more rapidly, protracted their whiskers further, and showed decreased whisking amplitude. These findings indicate a strategy change from using the vibrissae to explore nearby surfaces to using them primarily for "look ahead." In environments with increased risk of collision, functionally blind animals moved more slowly but protracted their whiskers further. Sighted animals also showed changes in whisker control strategy with increased familiarity, but these changes were different to those of the functionally blind strain. Sighted animals also changed their vibrissal behavior when visual cues were subsequently removed (by being placed in darkness). These contextual influences provide strong evidence of active control and demonstrate that the vibrissal system provides an accessible model of purposive behavior in mammals.
在探索过程中，老鼠和其他小型哺乳动物会用它们长长的面部触须（macro-vibrissae）进行有节奏的来回摆动[1-3]。这些“刷动”动作会受到头部运动[4]和触须感觉输入[5,6]的调节，因此通常被认为是在吉布森意义上的“主动”，即有目的和寻求信息[7,8]。主动感知的一个重要标志是根据上下文修改控制策略[9]。我们使用一个任务，在这个任务中，老鼠被训练为了食物而跑电路，我们测试了这样一个假设，即触须控制（通过高速录像测量）会根据环境熟悉度、碰撞风险和视觉线索可用性等上下文变量而改变。在新环境中，功能失明的老鼠以较慢的速度移动，并进行广泛的触须刷动。然而，随着对环境的熟悉程度增加，它们的移动速度更快，触须伸展得更远，刷动幅度减小。这些发现表明，从使用触须来探索附近的表面到主要使用触须来“向前看”，策略发生了变化。在碰撞风险增加的环境中，功能失明的动物移动得更慢，但触须伸展得更远。有视力的动物也随着熟悉程度的增加而改变了触须控制策略，但这些变化与功能失明的老鼠不同。当视觉线索随后被移除（放置在黑暗中）时，有视力的动物也会改变它们的触须行为。这些上下文影响为主动控制提供了强有力的证据，并表明触须系统为哺乳动物有目的的行为提供了一个可访问的模型。
