³My exposition is a kind of synthesis of different theories, and not all the mentioned properties are always associated with the two systems. Further, I should mention the proposals that the second, explicit system may be specialized in simulating hypothetical events that have not happened (Stanovich, 2004) for example for the purposes of planning, which will be considered in Chapter 9; or it could be mainly about working memory (Evans, 2008). An interesting related division between feedforward and feedback processing in neural networks is discussed by Lamme and Roelfsema (2000).