Task sharing can change the fate of task irrelevant information: Evidence from the joint Picture-Word interference paradigm

The joint version of the picture-word interference (PWI) paradigm was employed to investigate how people can deal with the task irrelevant information when they share an interference paradigm with another person. Participants performed the PWI paradigm, which requires to name a picture while ignoring a distractor word, both individually (baseline) and co-acting with an alleged partner (joint task). Results showed that, compared to the baseline and to a control condition in which participants continued to perform the PWI individually, the belief of co-acting with another individual suppressed the semantic interference effect (i.e., slower naming times for semantically related picture-word pairs) when the co-actor was thought to be in charge of the distractor words but not when s/he was thought to work on the same stimuli (pictures) as the participant. Task sharing was effective in eliminating the semantic interference effect only when written word recognition was made more difficult by presenting distractor words in case alternation letters (mOuSe). These results can be explained by assuming that the information about the co-actor’s task in a context of impaired word recognition would provide participants with an effective strategy to ignore the task irrelevant information when another person is in charge of this information.