Global and local processing in a Navon matching task

Studies examining global and local visual processing often make use of global shapes consisting of smaller local shapes (also known as Navon stimuli). Commonly, these stimuli are presented in isolation and participants are asked to respond or ignore shapes on the global or local level. We here report the results of an experiment in which participants were presented with two compound shapes simultaneously and were asked to either match these on a global and local level, resulting in a complex pattern of possible stimulus congruencies. Results show that matches at the global level are faster than at the local level. In contrast, error rates are only higher when stimuli do not match simultaneously on the global and local level during a local matching task. Mixed effects models suggest that the task has the largest effects on reaction times, followed by congruency on the global level, possibly moderated by global and local congruency.