Data_Sheet_1_An Adaptation of Pavlovian-to-Instrumental Transfer (PIT) Methodology to Examine the Energizing Effects of Reward-Predicting Cues on Behavior in Young Adults.PDF

There is growing recognition that much of human behavior is governed by the presence of classically conditioned cues. The Pavlovian-to-Instrumental Transfer (PIT) paradigm offers a way to measure the effects of classically conditioned stimuli on behavior. In the current study, a novel behavioral task, an adaptation of the PIT framework, was developed for use in conjunction with an fMRI classical conditioning task. Twenty-four healthy young adults completed (1) instrumental training, (2) Pavlovian conditioning, and (3) a Transfer test. During instrumental training, participants learned to apply force to a handgrip to win money from slot machines pictured on a computer screen. During Pavlovian conditioning, slot machines appeared with one of two abstract symbols (cues), one symbol was predictive of monetary reward. During the Transfer test, participants again applied force to a handgrip to win money. This time, the slot machines were presented with the Pavlovian cues, but with the outcomes hidden. The results indicated increased effort on the instrumental task, i.e. higher response frequency and greater force, in the presence of the reward-predicting cue. Our findings add to the growing number of studies demonstrating PIT effects in humans. This new paradigm is effective in measuring the effects of a conditioned stimulus on behavioral activation.

学界日益认识到，人类的诸多行为受经典条件反射线索的调控。巴甫洛夫-工具性转移（Pavlovian-to-Instrumental Transfer, PIT）范式为量化经典条件反射刺激对行为的影响提供了可行途径。本研究中，我们开发了一款基于PIT框架改良的全新行为任务，用于配合功能性磁共振成像（functional magnetic resonance imaging, fMRI）经典条件反射实验任务。24名健康青年成年人完成了三项实验流程：(1) 工具性训练、(2) 巴甫洛夫条件反射训练、(3) 转移测试。工具性训练阶段，受试者需对握力手柄施加力量，以从电脑屏幕上呈现的老虎机中赢取金钱奖励。巴甫洛夫条件反射训练阶段，老虎机将与两种抽象符号（线索）之一一同呈现，其中一种符号预示着金钱奖励。转移测试阶段，受试者需再次对握力手柄施加力量以赢取金钱。此时老虎机将搭配巴甫洛夫线索一同呈现，但奖励结果被隐藏。实验结果显示，当奖励预测线索出现时，受试者在工具性任务中的付出显著提升，具体表现为更高的反应频率与更大的握力。本研究结果进一步丰富了证实人类存在PIT效应的相关研究成果。这一全新范式可有效量化条件反射刺激对行为激活的影响。