The aim of this communication is to discuss the prominent role played by the concepts of Bounded Rationality and mental models within the broad tradition of New Institutional Economics (Williamson, 1975, 1996 North, 1988, Denzau and North 1994, Ostrom, 2005) and to propose a reassessment based on recent developments in cognitive theories of learning and situated cognition (Mantzavinos et al. 2004, Ostrom, 2005). In their article, Mantzavinos, North and Shariq (2004) especially emphasises new research directions for the foundations of a new cognitive institutionalism. A number of theoretical and empirical extensions are discussed.