| dc.description.abstract | In human participants, two paradigms commonly assumed to measure the executive-control processes involved in response inhibition are the Stop-Signal and Change-Signal tasks. There is, however, also considerable evidence that performance in these tasks can be mediated by associative processes. To assess which components of inhibitory response control might be associative, we developed analogues of these two tasks for pigeons. We trained pigeons to peck quickly at one of
two keys of different colours to obtain a food reward. On some trials, the rewarded key was replaced (after a varying interval) by a signal of a different colour. For some birds, this was a Change Signal: pecking the signal had no effect, but pecking the usually unrewarded alternative key led to a reward, so the response had to be changed. For other birds, the change in colour was a Stop Signal: pecking the alternative key remained ineffective, but pecking the signal now led to a timeout instead
of the usual reward, so responses had to be withheld. Pigeons succeeded in both tasks, but performance declined with increasing signal delay. The details of performance in both tasks were consistent with the independent horse-race model of inhibitory control often applied to studies of human participants. This outcome further suggests that stop-signal tasks of the kind used here might not be suitable for assessing top-down executive-control processes in humans. | en_GB |
