The influence of advanced information on co-representation in a shared finger precuing task.

Effective joint action relies on co-representation, where individuals integrate each other's tasks to achieve a shared task goal. This study examined how advanced information influences co-representation in a shared 4-choice finger precuing task where participants made discrete keypress responses to visual stimuli appearing at preassigned spatial locations. The five precue types varied in the amount of information about the upcoming stimulus location. In Experiment 1, participants first shared the 4-choice finger precuing task while sitting face-to-face (Joint 4-Choice, J4C), then they completed the entire 4-choice task alone (Solo 4-Choice, S4C). As anticipated, the standard precuing effect (reaction times [RTs] decrease as the amount of advanced information provided by the precue increases) was observed in the S4C task. However, a joint precuing effect was not elicited in the J4C task, suggesting that co-representation did not transpire. In Experiment 2, participants completed a modified solo version of the 4-choice finger precuing task (Solo 2-Choice, S2C), responding to only two of the four stimuli (Go trials) and ignoring the other two (NoGo trials). After completing the S2C task, participants completed the S4C task. The S2C task did not exhibit the standard precuing effect observed in the S4C task. Further analysis revealed that RTs were primarily influenced by the number of stimulus-response alternatives and modulated by the Go/NoGo context. Lastly, in Experiment 3, participants were seated side-by-side to enhance social context and verify that the spatial arrangement in Experiment 1 (face-to-face) did not inadvertently disrupt the social context needed to elicit co-representation. Despite eliminating this potential confounding factor by increasing proximity, no joint precuing effect was elicited. These findings advance our understanding of co-representation by demonstrating that it is not an automatic outcome of shared tasks and requires specific conditions (e.g., simultaneous actions, group-level representations) to manifest.