Specifying social cognitive processes with a social dual-task paradigm

Abstract

Automatic imitation tasks measuring motor priming effects showed that we directly map observed actions of other agents onto our own motor repertoire (direct matching). A recent joint action study using a social dual-task paradigm provided evidence for task monitoring. In the present study, we aimed to test (a) if automatic imitation is disturbed during joint action and (b) if task monitoring is content or time dependent. We used a social dual-task that was made of an automatic imitation task (Person 1: Task 1) and a two-choice number task (Person 2: Task 2). Each participant performed one of the two tasks, which were given with a variable stimulus onset asynchrony (SOA), in an individual and a joint condition. We found a regular motor priming effect in individual and joint conditions. Under joint conditions, we replicated the previous finding of an increase of reaction times for Person 2 with decreasing SOA. The latter effect was not related to the specific responses performed by both persons. Further, we did not find evidence for a representation of the other's specific S-R mappings. Our findings suggest that (a) automatic imitation is not disturbed during joint action and (b) task monitoring is time dependent.

Keywords: dual-task; joint action; social PRP; social cognition.

Figure 1

Experimental setup. Each participant performed one part of a dual-task. Person 1 (acting on Task 1) sitting on the left side had to execute finger-lifting movements (R1) with his right index or middle finger in response to a hand stimulus (S1). Person 2 (acting on Task 2) sitting on the right side had to respond with his right index or middle finger (R2) in response to a number stimulus (S2). (A) Both individuals perform their part of the dual-task together (joint condition). (B) One individual (Person 2) performs his part of the dual-task alone (individual condition).

Figure 2

Schematic illustration of the experimental design used in the present study. Thirty-two participants were randomly assigned to one part of a dual-task. Person 1 (Task 1) responded to finger-lifting movements of a hand stimulus (S1) either in an imitative or counterimitative way, the order of which was counterbalanced block wise across participants. Person 2 (Task 2) responded to a number stimulus (S2) presented between the moving fingers of the hand stimulus. Person 2 always responded with a fixed S(timulus)-R(esponse) mapping by lifting the index finger for digit 1 and lifting the middle finger for digit 2. Both tasks were performed in a joint and in an individual condition. The order of conditions was also counterbalanced across participants.

Figure 3

Effects of stimulus onset asynchrony (SOA) on reaction times of Task 2 (A) and Task 1 (B), separately for the joint (solid lines) and individual (dashed lines) condition.

Figure 4

Effects of stimulus onset asynchrony (SOA) on reaction times of Task 2 (A) and Task 1 (B) of the joint condition for S(timulus)1-R(esponse)1 compatible trials (black solid lines) and S1-R1 incompatible trials (gray solid lines).