Forms of momentum across space: representational, operational, and attentional.

Cognition can exhibit biases consistent with future expectations, and some of these biases result in momentum-like effects and have been linked with the idea of an internalization of the effects of momentum. These momentum-like effects include representational momentum, operational momentum, and attentional momentum. Similarities and differences between these different momentum-like effects are considered. Hubbard's (2005) review of representational momentum is updated to include studies published since that review appeared, and the first full reviews of operational momentum and attentional momentum are provided. It is suggested that (1) many variables that influence one of these momentum-like effects have a similar influence on another momentum-like effect, (2) representational momentum, operational momentum, and attentional momentum reflect similar or overlapping mechanisms, and operational momentum and attentional momentum are special cases of representational momentum, and (3) representational momentum, operational momentum, and attentional momentum reflect properties of a more general spatial representation in which change or transformation of a stimulus is mapped onto motion in a spatial coordinate system.