One of major paradigms in cognitive science is to model cognitive process as an in-
formation processing in the digital computer. Marr (1982) has proposed to capture the
cognitive process by the three levels of information processing, known as the levels of
hardware implementation, algorithm and representation, and computational theory. In
particular, the “computational theory” level is supposed most important among the
three, as it captures the goal of the information process and explains why the process
is organized so. It is, however, often controversial what to count as the computational
theory, and there are several variations in its interpretation. In this article, we review
these views on the computational theory, and overview the potential problems of the
computational theory in a narrow sense which have been pointed out in past literature.
By doing so, we discuss the aspects of the current paradigm to be extended toward a
new alternative paradigm beyond the formulation of cognition as optimization.