Noradrenergic Modulation by  tVNS has no Impact on  Computational Noise

Learning by trial and error is a very fundamental type of learning. In cognitive sciences, this concept is called reinforcement learning and is widely used for research, since it allows comparably easy operationalisation. In order to translate this into computable data, models of reinforcement learning such as the Rescorla-Wagner learning rule are used. These models usually neglect disturbance in learning, which is called computational noise and reduces the precision of neural computations during the learning process. Recent research has looked further into exactly this parameter of learning and found that it indeed plays a big part and should not be neglected (Drugowitsch, Wyart, Devauchelle & Koechlin, 2016). Besides replicating a study by Findling and colleagues (2019), this study specifically looks into the role of noradrenaline in the reinforcement learning process and learning noise. Noradrenaline excretion was triggered by transcutaneous vagus nerve stimulation, while a two...Show moreLearning by trial and error is a very fundamental type of learning. In cognitive sciences, this concept is called reinforcement learning and is widely used for research, since it allows comparably easy operationalisation. In order to translate this into computable data, models of reinforcement learning such as the Rescorla-Wagner learning rule are used. These models usually neglect disturbance in learning, which is called computational noise and reduces the precision of neural computations during the learning process. Recent research has looked further into exactly this parameter of learning and found that it indeed plays a big part and should not be neglected (Drugowitsch, Wyart, Devauchelle & Koechlin, 2016). Besides replicating a study by Findling and colleagues (2019), this study specifically looks into the role of noradrenaline in the reinforcement learning process and learning noise. Noradrenaline excretion was triggered by transcutaneous vagus nerve stimulation, while a two-armed bandit task was used as learning task. We did not find significant effects of this neurotransmitter on the learning process, however, successfully replicated the research of Findling et al. (2019). These results imply that computational noise during the learning process is still a crucial factor in reinforcement learning and should therefore be further investigated. Noradrenaline might not impact the amount of learning noise to the expected extent.Show less

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Noradrenergic Modulation by tVNS has no Impact on Computational Noise