String-pulling for food by the rat: Assessment of movement, topography and kinematics of a bilaterally skilled forelimb act

Publication date: February 2018Source: Learning and Motivation, Volume 61Author(s): Ashley A. Blackwell, Jenny R. Köppen, Ian Q. Whishaw, Douglas G. WallaceAbstractA variety of behavioral tests have been developed to assess skilled forelimb function in the rat, including tests that assess use of a single limb in reaching for food and placing it in the mouth for eating. The present study describes bilateral hand use in string-pulling to obtain a food reward. The movement consists of alternating forelimb movements in which a limb is advanced to grasp a string and withdraw it toward the body in order to retrieve a food reward. The movements of aim, advance, grasp, pull and push are associated with hand shape changes including collect, overgrasp, grasp and release. The topography and kinematics of limb and hand movement are assessed by digitizing methods that derive trajectory, distance, and velocity measures. The task is acquired by a rat within a few days of training, features few missed grasps, shows improvements with practice, and yields dozens of independent reaches by each hand in a single test session. The present analysis provides simple methods for describing each independent forelimb and hand movement and its topographic and kinematic properties. The similarities between string-pulling and other rat forelimb movements are discussed in relation to the idea that rat forelimb movements are conserved in tasks such as string-pulling, walking, reaching for food and grid walk...
Source: Learning and Motivation - Category: Psychiatry & Psychology Source Type: research