Mutuality relations, observation, and intentional constraints

Stoffregen (target article, this issue) asks whether animals detect informa tion specific to events and therefore perceive events as such, or whether a nimals always perceive affordances, which reflect the possibilities for act ion of a surrounding layout of surfaces. He concludes the latter. We examin e this issue with special reference to the concepts of (a) the simultaneity of exteroception and proprioception, (b) observation, and (c) intention as a constraint on information detection. We argue that animals do not always have to perceive affordances and that during observation, events (in relat ion to the animal) may be perceived. We discuss the role of intention in co nstraining mutuality relations with respect to specific behaviors.