2013, Pickering Garrod, 2007, and Brown Kuperberg, 2015, for perspectives on language processing). Within such a framework, the comprehender would achieve her goal of inferring the producer’s message by incrementally updating her hypotheses about the underlying message being conveyed on the basis of each new piece of information as it becomes available. Such inference and belief updating, which we described for syntactic parsing in section 1, would proceed at all levels of the hierarchy of linguistic representation. As discussed in section 1, so long as the comprehender’s probabilistic knowledge at these levels of the hierarchy closely resembles the actual statistics of the linguistic input, then she should be able to use it to maximize the average probability of correctly (and perhaps more quickly) recognizing incoming information at these levels of representation. This, in turn, should enable information to pass more efficiently up the hierarchy so that she can update her messagelevel representation of context (3-MethyladenineMedChemExpress 3-MA indeed, within some frameworks, such as predictive coding, it is only the information that is unpredicted — or `unexplained’ — that is passed up from lower to higher levels of the hierarchy, see Clark, 2013; Friston, 2005). In the next section, we will extend this idea by arguing that, under some OPC-8212MedChemExpress Vesnarinone circumstances, information does not just flow up the hierarchy, in a bottom-up fashion, but that it can also flow down the hierarchy, with information at higher levels being used, under some circumstances, to predictively pre-activate information at lower levels.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptSection 3: Predictive pre-activationThe data and the debates In section 2 we presented further evidence that we can use multiple types of information in the context to facilitate processing of new inputs at multiple different representational levels. Facilitation, however, does not necessarily imply predictive pre-activation. To give a concrete example, imagine reading the context in (2) and finding that it can be used to facilitate processing at the phonological level (e.g. the consonant /kh/ or the phonemes /k/`, / I/`, and /t/). Just before encountering the incoming word “kite”, our internal representation of context is likely to include a hypothesis, held with a high degree of belief, at an event level of representation, that the event being conveyed is . In theory, there are two possibilities for how this high level inference/hypothesis might facilitate phonological processing of the incoming word, “kite”. The first is that we wait for the bottom-up input,Lang Cogn Neurosci. Author manuscript; available in PMC 2017 January 01.Kuperberg and JaegerPage”kite”, to activate its phonological representation (and its neighbors), and we then use our high level event hypothesis to select the correct phonological representation. The second possibility is that we use our high level event hypothesis to predictively pre-activate the phonological representation of “kite” prior to the bottom-up input reaching this lower phonological level of representation. In this section, we discuss this debate about whether or not we can actually predictively preactivate information at lower representational levels on the basis of information at higher levels within our internal representations of context, ahead of the bottom-up input reaching these lower levels. This debate has a long history in the language p.2013, Pickering Garrod, 2007, and Brown Kuperberg, 2015, for perspectives on language processing). Within such a framework, the comprehender would achieve her goal of inferring the producer’s message by incrementally updating her hypotheses about the underlying message being conveyed on the basis of each new piece of information as it becomes available. Such inference and belief updating, which we described for syntactic parsing in section 1, would proceed at all levels of the hierarchy of linguistic representation. As discussed in section 1, so long as the comprehender’s probabilistic knowledge at these levels of the hierarchy closely resembles the actual statistics of the linguistic input, then she should be able to use it to maximize the average probability of correctly (and perhaps more quickly) recognizing incoming information at these levels of representation. This, in turn, should enable information to pass more efficiently up the hierarchy so that she can update her messagelevel representation of context (indeed, within some frameworks, such as predictive coding, it is only the information that is unpredicted — or `unexplained’ — that is passed up from lower to higher levels of the hierarchy, see Clark, 2013; Friston, 2005). In the next section, we will extend this idea by arguing that, under some circumstances, information does not just flow up the hierarchy, in a bottom-up fashion, but that it can also flow down the hierarchy, with information at higher levels being used, under some circumstances, to predictively pre-activate information at lower levels.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptSection 3: Predictive pre-activationThe data and the debates In section 2 we presented further evidence that we can use multiple types of information in the context to facilitate processing of new inputs at multiple different representational levels. Facilitation, however, does not necessarily imply predictive pre-activation. To give a concrete example, imagine reading the context in (2) and finding that it can be used to facilitate processing at the phonological level (e.g. the consonant /kh/ or the phonemes /k/`, / I/`, and /t/). Just before encountering the incoming word “kite”, our internal representation of context is likely to include a hypothesis, held with a high degree of belief, at an event level of representation, that the event being conveyed is . In theory, there are two possibilities for how this high level inference/hypothesis might facilitate phonological processing of the incoming word, “kite”. The first is that we wait for the bottom-up input,Lang Cogn Neurosci. Author manuscript; available in PMC 2017 January 01.Kuperberg and JaegerPage”kite”, to activate its phonological representation (and its neighbors), and we then use our high level event hypothesis to select the correct phonological representation. The second possibility is that we use our high level event hypothesis to predictively pre-activate the phonological representation of “kite” prior to the bottom-up input reaching this lower phonological level of representation. In this section, we discuss this debate about whether or not we can actually predictively preactivate information at lower representational levels on the basis of information at higher levels within our internal representations of context, ahead of the bottom-up input reaching these lower levels. This debate has a long history in the language p.