Wilhelm Wundt Institute for Psychology, Leipzig University, Leipzig, Germany.
Eur J Neurosci. 2024 Jul;60(2):4049-4062. doi: 10.1111/ejn.16393. Epub 2024 May 19.
Recent theories describe perception as an inferential process based on internal predictive models that are adjusted by prediction violations (prediction error). Two different modulations of the auditory N1 event-related brain potential component are often discussed as an expression of auditory predictive processing. The sound-related N1 component is attenuated for self-generated sounds compared to the N1 elicited by externally generated sounds (N1 suppression). An omission-related component in the N1 time-range is elicited when the self-generated sounds are occasionally omitted (omission N1). Both phenomena were explained by action-related forward modelling, which takes place when the sensory input is predictable: prediction error signals are reduced when predicted sensory input is presented (N1 suppression) and elicited when predicted sensory input is omitted (omission N1). This common theoretical account is appealing but has not yet been directly tested. We manipulated the predictability of a sound in a self-generation paradigm in which, in two conditions, either 80% or 50% of the button presses did generate a sound, inducing a strong or a weak expectation for the occurrence of the sound. Consistent with the forward modelling account, an omission N1 was observed in the 80% but not in the 50% condition. However, N1 suppression was highly similar in both conditions. Thus, our results demonstrate a clear effect of predictability for the omission N1 but not for the N1 suppression. These results imply that the two phenomena rely (at least in part) on different mechanisms and challenge prediction related accounts of N1 suppression.
最近的理论将感知描述为一种基于内部预测模型的推理过程，这些模型通过预测违反（预测误差）进行调整。听觉 N1 事件相关脑电位成分的两种不同调制经常被讨论为听觉预测处理的表达。与外部产生的声音相比，自我产生的声音的声音相关 N1 成分会减弱（N1 抑制）。当自我产生的声音偶尔被省略时，N1 时间范围内会引出一个与省略相关的成分（省略 N1）。这两种现象都可以通过与动作相关的前向建模来解释，当感觉输入是可预测的时候，前向建模就会发生：当呈现预测的感觉输入时，预测误差信号会减少（N1 抑制），当预测的感觉输入被省略时，预测误差信号会被引出（省略 N1）。这个共同的理论解释很有吸引力，但尚未得到直接验证。我们在自我产生范式中操纵了声音的可预测性，在两种条件下，要么 80%，要么 50%的按钮按压会产生声音，从而对声音的发生产生强烈或较弱的期望。与前向建模的解释一致，在 80%的条件下观察到了省略 N1，但在 50%的条件下没有观察到。然而，N1 抑制在两种情况下非常相似。因此，我们的结果表明，可预测性对省略 N1 有明显的影响，但对 N1 抑制没有影响。这些结果意味着这两种现象依赖（至少部分）于不同的机制，并挑战了与预测相关的 N1 抑制解释。
