LAUSR

This special issue aims at bringing together two debates in recent philosophy of mind. The first debate is part of the philosophy of perceptual experience. We observe an intense discussion on the question whether the activation of higher-level cognitive states like concepts, beliefs, desires etc. is capable of influencing perceptual experience, while this modification would only be interesting if it affects perceptual process and not just the perceptual input or the perceptual judgment. Such a phenomenon is known as the cognitive penetrability of perceptual experience (CP). The second debate is based on the introduction of a new functional framework for analyzing brain processes, namely the predictive coding framework (PCF), with the open question of how fruitfully this framework can be used to reach explanations of central phenomena of the human mind including perception. The central idea of predictive coding, as put forward recently in some detailed accounts especially by Friston (2010), Hohwy (2013) and Clark (2013), states that the brain constantly models the outer world according to Bayesian principles, in order to predict the incoming sensory information. To make a connection with the debate about CP, which is usually discussed relying on the example of visual experience, PCF must be applicable on the relevant levels of perceptual processing. The basic idea is the following: the prior predictive information is fed down to lower stages via feed-back connections and influences the processing on these lower levels. At the relevant lower level, the predicted information and the incoming sensory information are compared, and a possible mismatch is extracted as an error signal. This error signal is communicated in a feed-forward way to the higher levels of processing where it corrects and adjusts the predictive model. Via further recurrent loops, a better predictive model is computed and fed down again to the sensory input layer until a sufficiently low error signal is achieved. In PCF, top-down influences play a crucial role as they carry the most important information: the prediction on how the sensory information is likely to be composed. The special issue is structured into one introductory section and two main sections with the first investigating the core of the debate about CP and the second addressing the relation between CP and PCF, a topic that has never been specifically addressed so far in a dedicated volume.