Rewards can be costly: extrinsic rewards are not beneficial during autonomous learning

Intrinsic factors like the feeling of control and extrinsic factors like monetary reward can both benefit learning. However, little is known about whether both effects are additive, or interact to affect learning performance. To shed light on this open question, 36 participants took part in an explorative learning task during which they viewed partially obscured images that they needed to subsequently remember. During the learning task, autonomy, operationalised as volitional control over an exploration trajectory, and the chance to receive monetary rewards were independently manipulated. The learning task was followed by a memory test. The results demonstrated that autonomy benefits recognition memory. Rewards also improved recognition memory, but only when participants were not acting autonomously. These findings have important implications for educational settings, in which both autonomy and extrinsic rewards (i.e., grades) are commonly used to motivate students.