The role of action affordances in visual object recognition

Brain areas involved in action representation (pre-motor cortex, posterior parietal cortex) are activated when subjects name pictures of artifactual objects, like tools (eg Chao and Martin, 2000 NeuroImage 12 478 - 484). Moreover, psychophysical evidence indicates that manipulable objects automatically potentiate possible actions (eg Tucker and Ellis, 1998 Journal of Experimental Psychology: Human Perception and Performance 24 830 - 846). We investigated whether knowledge about action affordances is actually involved in object recognition. We examined with a priming paradigm whether objects with congruent affordances are named more accurately than objects with incongruent affordances. Two gray-scale pictures of artifactual manipulable objects were sequentially presented (tools, kitchen utensils, musical instruments). Subjects were required to name the objects. Stimuli were briefly presented and masked. The presentation time of the second object was adjusted individually in an adjustment phase so that accuracy approached 80. In the congruent condition, both objects afford the same action (eg 'twisting', 'pouring'), while the affordances differ in the incongruent condition. Stimulus pairs in both conditions were matched for baseline accuracy, word frequency, word length, as well as visual and semantic similarity. Naming accuracy was significantly higher in the congruent condition. These findings substantiate our hypothesis that action affordances play an important role in the identification of artifactual manipulable objects