The size coding of responses: The size of switches and the force feedback

We aimed to understand which factors have a functional role in the size coding of responses, either the size of the switches or the force required to trigger each switch. This question is of relevance because it allows a better understanding of processes underlying action coding. In each trial, participants saw a small or large object. Depending on its colour, the participants had to press one of two switches. In the "size" condition, the response device consisted of two switches of different visual size, but both required the same amount of force. In the "force-feedback" condition, the response device consisted in two switches of identical visual size, but one switch required more force than the other. We found a compatibility effect in the "size," not in the "force-feedback" condition, supporting that the size-coding of responses would be due to the size of the switches.