预测错误最小化与幻觉——论预测加工理论对幻觉问题的解决

Prediction Error Minimization and Hallucination--On the Solution of Hallucination by Predictive Processing Theory

幻觉经验具有与真实知觉经验相似的体验特征,却没有像真实知觉那样正确呈现外部对象,因此对我们理解知觉造成了挑战。然而,无论是析取论对真实知觉和幻觉的二分,还是同类假说对两者做同一类解释,都无法让人满意。近些年兴起的预测加工理论不但可以解释幻觉为何以及如何产生,还可以解释具有与真实知觉相似体验的幻觉为何会错误表征。预测加工理论认为,不论是真实知觉,还是幻觉,都是大脑的预测,只不过真实知觉是受控的预测,而幻觉是失控的预测。真实知觉之所以正确表征了知觉对象在于其正确最小化了预测错误,幻觉之所以表征了不存在的知觉对象在于其预测精度失调,从而选定了错误的假设来最小化预测错误。

Hallucinatory experience has the experience character similar to perceptual experience,but it doesn’t present the external objects correctly like perceptual experience,so it poses a challenge to our understanding of per⁃ception.However,neither disjunctive dichotomy of perception and hallucination nor the common kind theory’s common explanation of them are satisfactory.Predictive processing theory,which has emerged in recent years,can explain not only why and how hallucination occurs,but also why hallucinations with experiences similar to percep⁃tion are misrepresented.According to predictive processing theory,both perception and hallucination are the predic⁃tions of the brain,but perception is the controlled prediction while hallucination is the uncontrolled prediction.The reason why perception correctly represents the object of perception is that it correctly minimizes the prediction error,and the reason why hallucination represents the nonexistent object of perception is that its prediction precision is im⁃precise,so it selects the wrong hypothesis to minimize the prediction error.