The importance of object similarity in the production and identification of actions associated with objects.

Past research suggests that the similarity between the objects associated with actions impacts visual action identification and action production. Indeed, people often confuse actions that are visually similar, as well as actions that are associated with visually similar objects. However, because the action errors often involve actions that are visually similar and are associated with visually similar objects, it is difficult to disambiguate between the influences of object similarity and action similarity. In our experiments, healthy participants were asked to learn to associate nonword names and actions with novel objects. Participants were first shown each object and its action and were then asked to visually identify each object. In Experiment 1, participants were then asked to produce the action associated with each object, and in Experiment 2, they were asked to visually identify the action associated with each object. Actions were confused more often when they were associated with similar objects than when they were associated with dissimilar objects. Furthermore, following an object naming error, participants were more likely to produce the action associated with the erroneous name than any other erroneous action. The results suggest that the visual characteristics of the objects influenced action production and action identification.