The recently proposed action-concept view of perceptual-motor behaviour posits that a stimulus which consistently follows a certain response will become associated with that response. Some evidence in favour of this view comes from the finding that the size of the Simon effect can be altered by the inclusion of post-response stimuli. However, only one study has investigated the effects of including same-side in addition to opposite-side post-response stimuli, as well as a neutral Simon condition, and, possibly because of a failure of random assignment, the results from that study were inconclusive. In light of this limitation, a Simon experiment was performed in which the location of post-response stimulation was manipulated within subjects. The results showed that: (1) the Simon effect can both decrease and increase in the presence of post-response stimuli, and (2) the amounts of Simon interference and Simon facilitation are both affected by post-response stimuli, whereas performance on neutral trials is not. These findings provide additional support for the action-concept view and suggest that further research concerning this new approach is warranted.