Bermejo R, Zeigler H P
Department of Psychology, Hunter College [CUNY], New York, NY 10021, USA.
Behav Brain Res. 1998 Mar;91(1-2):173-84. doi: 10.1016/s0166-4328(97)00121-6.
Like human prehensile behavior, the pigeon's ingestive pecking response is elicited by visual stimuli conveying information about the location and size of the target. This information is used to generate localized ingestive pecks whose gapes are amplitude-scaled to seed size, prior to contact. We employed high-resolution, 'real-time' monitoring of head acceleration, jaw movements and terminal peck location to examine the kinematics, coordination and stimulus control of conditioned pecking. Conditioning procedures were used to bring pecking under the control of visual targets whose stimulus properties (size, location) were independently varied, while simultaneously monitoring pecking response parameters. Stimulus control of the transport component (peck localization) is extremely precise, even in the absence of a specific localization-dependent reinforcement contingency. Subjects also showed amplitude-scaling of gape size to the size of a visual target, but over a more restricted range than shown to food pellets of comparable sizes. Comparison of the kinematic profiles of conditioned and ingestive pecks suggests that conditioned pecking is functionally analogous to human 'pointing' rather than 'grasping' behavior.
与人类的抓握行为类似，鸽子的摄取性啄食反应是由传达目标位置和大小信息的视觉刺激引发的。在接触之前，这些信息被用于产生局部摄取性啄食，其张口幅度根据种子大小进行缩放。我们采用高分辨率的“实时”监测头部加速度、颌部运动和最终啄食位置，以研究条件性啄食的运动学、协调性和刺激控制。使用条件化程序使啄食受视觉目标控制，这些视觉目标的刺激属性（大小、位置）可独立变化，同时监测啄食反应参数。即使在没有特定的依赖定位强化意外情况时，运输成分（啄食定位）的刺激控制也极其精确。实验对象还表现出张口大小根据视觉目标大小进行缩放，但范围比在类似大小的食物颗粒上显示的范围更有限。条件性啄食和摄取性啄食的运动学特征比较表明，条件性啄食在功能上类似于人类的“指向”行为，而不是“抓握”行为。
