When co-action eliminates the Simon effect: disentangling the impact of co-actor's presence and task sharing on joint-task performance

Abstract

This study aimed at assessing whether the mere belief of performing a task with another person, who is in charge of the complementary part of the task, is sufficient for the so-called joint Simon effect to occur. In all three experiments of the study, participants sat alone in a room and underwent two consecutive Go/NoGo tasks that were identical except for the instructions. In Experiment 1, participants performed the task first individually (baseline task), and then either co-acting with another person who responded from an unknown location to the NoGo stimuli (joint task) or imaging themselves responding to the NoGo stimuli (imaginative task). Relative to the baseline, the instructions of the imaginative task made the Simon effect occur, while those of the joint task were ineffective in eliciting the effect. This result suggests that sharing a task with a person who is known to be in charge of the complementary task, but is not physically present, is not sufficient to induce the representation of an alternative response able to produce interference, which happens instead when the instructions explicitly require to imagine such a response. Interestingly, we observed that when the Simon effect was already present in the baseline task (i.e., when the response alternative to the Go response was represented in the individual task due to non-social factors), it disappeared in the joint task. We propose that, when no information about the co-actor's position is available, the division of labor between the participant and co-actor allows participants to filter out the possible (incidental) representation of the alternative response from their task representation, thus eliminating potential sources of interference. This account is supported by the results of Experiments 2 and 3 and suggests that under certain circumstances task-sharing may reduce the interference produced by the irrelevant information, rather than increase it.

Interacting hands: the role of attention for the joint Simon effect

“… Guagnano et al (2010) showed that the JSE, which is observed when two actors respond in peripersonal space, is diminished when they are located in extrapersonal space (out of reach distance). A similar finding is observed when the co-actor is placed in a separate room, which is spatially not further specified ( Welsh et al, 2007 ; Sellaro et al, 2013 ; but see Tsai et al, 2008 ).…”

Exploring social influences on the joint Simon task: empathy and friendship

“…The phenomenon of a SE in the absence of a co-actor mimics findings from previous research whereby the effect was observed even when the co-actors were unable to see or hear each other (e.g., Tsai et al, 2008 ; Vlainic et al, 2010 ). It could be argued that the individual SE reflected a carrying forward of spatial response codes acquired during the earlier joint paradigm, in line with evidence of similar transfer effects when participants proceed to a go/no-go version of the Simon task after previously having performed the standard two-handed version ( Ansorge and Wühr, 2009 ; and see Sellaro et al, 2013 , for a response-discrimination account of the Tsai et al, 2008 findings). However, the finding that the individual SE for friends was correlated positively with fantasizing raises the possibility that participants continued to conceptualize the task as a joint activity 1 .…”

“…The joint SE has been observed when participants perform the task from different rooms ( Tsai et al, 2008 ), and when they are prevented from seeing and hearing each other during the activity ( Vlainic et al, 2010 ). In contrast, two studies found no joint SE when co-actors were physically separated ( Welsh et al, 2007 ; Sellaro et al, 2013 ).…”

Referential coding does not rely on location features: Evidence for a nonspatial joint Simon effect.

“…Hence, the referential coding approach shares the assumption of the spatial response coding account that spatial response coding is the crucial factor for the JSE to occur, but it develops a different scenario of why responses are 1 It is worth mentioning that Tsai, Kuo, Hung, and Tzeng (2008) did observe a JSE when the actor and the coactor performed the joint Simon task in two different rooms. However, as underlined by Sellaro et al (2013), the occurrence of the JSE in Tsai's et al study is likely to reflect confounding spatial factors underlying their experimental procedure. This document is copyrighted by the American Psychological Association or one of its allied publishers.…”