Cerebral coherence between communicators marks the emergence of meaning

Supporting Information

Files in this Data Supplement:

• Download Supporting Information (PDF)
• Download Movie_S01 (WMV) - Interactive behaviors evoked during trial 25 of participant pair 8. All movies reproduce exactly the behavior of the participants recorded during the trials on display, with 1 s added before and after each transition across trial epochs to facilitate vision of the trial sequence. Movies S1–S4 show how different conversational contexts may evoke different communicative signals with the same meaning. For instance, subjectively interpreted, the Communicator of pair 8 (in blue) moves to the goal position of the Addressee’s token, after which he leaves that grid point along the direction her triangle needs to point and back (labeled as a wiggle strategy) to indicate the desired orientation (Movie S1). In contrast, the Communicator of pair 6 first indicates the desired orientation of the Addressee’s token by stepping outside the starting grid point along the same direction (and back to the starting position in the center) before moving to the goal position of the Addressee’s token (Movie S2). Another communicative signal type is observed in pair 19, in which the Communicator uses the direction in which he moves away from the Addressee’s goal position to his own goal position (“exit-point strategy”) as a marker for the desired orientation of the Addressee’s token (Movie S3). However, another signal type is observed in pair 24, in which the Communicator mimics the desired rotational movements of the Addressee by drawing circles on the game board: we infer two circles to indicate two rotations (Movie S4).
• Download Movie_S02 (WMV) - Interactive behaviors evoked during trial 25 of participant pair 6.
• Download Movie_S03 (WMV) - Interactive behaviors evoked during trial 25 of participant pair 19.
• Download Movie_S04 (WMV) - Interactive behaviors evoked during trial 25 of participant pair 24.
• Download Movie_S05 (WMV) - Interactive behaviors evoked by participant pair 15 during trial 10. Movies S5–S7 show how a particular problem type can induce different communicative signals in different trials, depending on the recent communicative history of a pair. For instance, in trial 10, the Communicator of pair 15 rotates his rectangular token to indicate to the Addressee the goal configuration of her token (Movie S5). In trial 27, despite the fact that the problem in this trial is similar to the problem of trial 10, a different communicative signal (labeled as a wiggle) was observed (Movie S6). Why did this pair decide to abandon a successful signal? Judging from their previous interactions, e.g., trial 25, it seems that the pair had converged on the wiggle signal for a different problem and continued to use it given their recent communicative history (Movie S7).
• Download Movie_S06 (WMV) - Interactive behaviors evoked by participant pair 15 during trial 27.
• Download Movie_S07 (WMV) - Interactive behaviors evoked by participant pair 15 during trial 25.