THE CAUSAL FUNCTIONAL ROLE OF ACTION-EFFECT BINDINGS

funded by Deutsche Forschungsgemeinschaft (DFG)

Principal Investigators: Prof. Dr. Bernhard Hommel, Prof. Dr. Christian Beste

How is it possible that people can carry out intentional actions? The ideomotor theory suggests that people begin by carrying out random, non-intentional movements first (e.g., as a baby) and then automatically associate the motor patterns producing these movements with the perceptual representations the movements generate (e.g., the rattling movement to the sound of the rattle). If, then, the person wishes to produce this effect intentionally, she only needs to “think of” this effect, which reactivates the associated motor pattern and, voila: the movement is produced. Previous studies have provided evidence that people do associate actions with perceptual outcomes, and that they reactivate the representations of these outcomes in the process of planning the corresponding action. But whether effect representations really play a causal role in action planning is not yet clear: agent may simply anticipate outcomes, but this anticipation need not be necessary to program the action.

Our project aims to provide the missing causal information. We will be using an electrophysiological marker of action-effect representations that will show us when and how strongly people are “thinking of” an action’s outcome. Then we will use transcranial magnetic stimulation to “switch off” this thought by means of strong magnetic fields. If these thoughts are indeed causal, this intervention should impair the action-planning process.