Abstract
We investigated the factors to select the stimulus and response properties, especially links between object and action. Riddoch, Humphreys, and Edward (2000) reported data from a patient with cortical basal degeneration, suggested the inhibition effect of the distractor varied dependent on the stimulus-response association when the distractor was attended, that is, response blocking effect. The mechanisms of this response blocking are considered to be caused by object-action assemblies, which are longer lasting links between object and action. Monsell, Yeung and Azuma (2000) suggested that task repeating or switching was related with stimulus and response association. In order to clarify the factors to select object and action, we measured the inhibition effect, the compatibility effect, and the task switching. Healthy participants viewed two arrows or one arrow and one bar in a horizontal position. Before this display, an endogenous cue was presented in order to indicate the dimension to be selected and responded the direction of the target arrow or the location while ignoring the distractor. Each effect is defined by the relationship between the target and distractor stimulus (the inhibition effect), the target stimulus and -associated response (the compatibility effect), and the task repeating and changing (the task switching). The response blocking effect is manifested by the inhibition effect dependent on the compatibility. As a result, the response blocking effect was observed even by healthy participants. And the occurrence of this effect depended on task switching or not. Furthermore, our result in the task switching implies that a task set contains not only an instruction task set in inter-trial but also the presence of the task switching context in inter-experiment. These results suggest that the temporal links between object and action as task switching, other than object-action assemblies, decide the object and action selection.