Affordances, Adaptive Tool Use and Grounded Cognition

The role of affordances In our opinion the model would be improved if affordance for action mechanisms were integrated: The potentiation of motor interactions consistent with the conventional use of a perceived tool (Bub et al., 2008). Affordances would easily explain the mechanism underlying the quick choice of the most appropriate tool when an action goal is given. In Figure 1A, bidirectional connections between available tools and usage contexts represent the automatic activation of stable affordances (Borghi and Riggio, 2009) emerging from invariant features of the tool (mainly its functional meaning) incorporated into the object representation in long term memory (e.g., a spoon typically stirs and scoops, a knife cuts and spreads). Activation of stable affordances is independent of context or task to be carried out. Furthermore, for each stable affordance, variable affordances emerging from temporary characteristics of the tools such as their current handle orientation are also activated. When an action goal is given (stir the coffee), attention is restricted to a specific action context (to stir) and oriented to available and action-consistent tools (spoon and stirrer). Thus, activation of a restricted number of stable and variable affordances is privileged (e.g., “spoon + to stir” and “stirrer + to stir” with the right hand) over those not consistent with the action goal. Here, the controller will select “spoon + to stir” instead of “stirrer + to stir” and execute the required action with the hand corresponding to the handle orientation. Selection between two equally appropriate tools is assumed to be determined by stronger stable and variable affordances being activated. A commentary on