Visualisations play an important part in the development of ideas. They make ingredients and relations explicit, guide thinking processes of the designer or scientist, and support communications, often across the boundaries of disciplines. In the fields of cognitive psychology and human-machine interaction, block diagrams have been a dominant means for representing cognitive systems. However, we believe that this form of representation may constrain how we think about cognition in undesirable ways. This form of representation biases viewers to see cognition as a sequential, step-by-step process, under emphasizing the dynamical properties of closed-loop, adaptive processes. Block diagrams emphasize activity and internal mental operations (awareness) and occlude the ecological or work domain (situational) constraints.