Radboud University, Donders Institute for Brain, Cognition, and Behaviour, 6525 GD Nijmegen, The Netherlands
Department of Experimental Psychology, University of Oxford, Oxford OX1 3TA, United Kingdom.
Learn Mem. 2024 Sep 16;31(8). doi: 10.1101/lm.054017.124. Print 2024 Aug.
"Pavlovian" or "motivational" biases are the phenomenon that the valence of prospective outcomes modulates action invigoration: the prospect of reward invigorates actions, while the prospect of punishment suppresses actions. Effects of the valence of prospective outcomes are well established, but it remains unclear how the magnitude of outcomes ("stake magnitude") modulates these biases. In this preregistered study ( = 55), we manipulated stake magnitude (high vs. low) in an orthogonalized Motivational Go/NoGo Task. We tested whether higher stakes (a) strengthen biases or (b) elicit cognitive control recruitment, enhancing the suppression of biases in motivationally incongruent conditions. Confirmatory tests showed that high stakes slowed down responding, especially in motivationally incongruent conditions. However, high stakes did not affect whether a response was made or not, and did not change the magnitude of Pavlovian biases. Reinforcement-learning drift-diffusion models (RL-DDMs) fit to the data suggested that response slowing was best captured by stakes prolonging the non-decision time. There was no effect of the stakes on the response threshold (as in typical speed-accuracy trade-offs). In sum, these results suggest that high stakes slow down responses without affecting the expression of Pavlovian biases in behavior. We speculate that this slowing under high stakes might reflect heightened cognitive control, which is however ineffectively used, or reflect positive conditioned suppression, i.e., the interference between goal-directed and consummatory behaviors, a phenomenon previously observed in rodents that might also exist in humans. Pavlovian biases and slowing under high stakes may arise in parallel to each other.
“巴甫洛夫”或“动机”偏差是指预期结果的效价调节行为激发的现象：奖励的前景激发行为，而惩罚的前景抑制行为。预期结果的效价的影响是明确的，但尚不清楚结果的大小（“赌注大小”）如何调节这些偏差。在这项预先注册的研究（n=55）中，我们在正交动机 Go/NoGo 任务中操纵了赌注大小（高与低）。我们测试了较高的赌注是否会（a）增强偏差，或（b）引起认知控制招募，从而增强动机不一致条件下对偏差的抑制。验证性测试表明，高赌注会使反应速度减慢，尤其是在动机不一致的情况下。然而，高赌注并不影响是否做出反应，也不会改变巴甫洛夫偏差的幅度。强化学习漂移扩散模型（RL-DDM）拟合数据表明，反应速度的减慢最好由赌注延长非决策时间来解释。赌注对反应阈值没有影响（如典型的速度准确性权衡）。总之，这些结果表明，高赌注会减慢反应速度，而不会影响行为中表现出的巴甫洛夫偏差。我们推测，高赌注下的这种减速可能反映了认知控制的提高，但这种提高没有得到有效利用，或者反映了积极的条件性抑制，即目标导向和满足性行为之间的干扰，这种现象以前在啮齿动物中观察到，也可能存在于人类中。巴甫洛夫偏差和高赌注下的减速可能同时出现。
