Norms for grip agreement for 296 photographs of objects.

An increasing number of studies are investigating the cognitive processes underlying human-object interactions. For instance, several researchers have manipulated the type of grip associated with objects in order to study the role of the objects' motor affordances in cognition. The objective of the present study was to develop norms for the types of grip employed when grasping and using objects, with a set of 296 photographs of objects. On the basis of these ratings, we computed measures of agreement to evaluate the extent to which participants agreed about the grip used to interact with these objects. We also collected ratings on the dissimilarity between the grips employed for grasping and for using objects, as well as the number of actions that can typically be performed with the objects. Our results showed grip agreements of 67 % for grasping and of 65 % for using objects. Moreover, our pattern of correlations is highly consistent with the idea that the grips for grasping and using objects represent two different motor dimensions of the objects.