Figure 1. Trial design.

The figure shows three exemplary experimental trials (a–c). (a) illustrates a trial with audiovisual (AV) laughter presentation while (b) and (c) show visual (V) and auditory (A) trials, respectively. The participants’ task was to evaluate on a four-point scale if and how clearly the laughter expressed a friendly (German: “Anlachen”) or an unfriendly (German: “Auslachen”) social intention. The English expressions “FRIENDLY LAUGHTER” and “UNFRIENDLY LAUGHTER” above the German expressions “ANLACHEN” and “AUSLACHEN” are not part of the original scale shown in the experiment but were inserted to enhance the comprehensibility of the figure. Time specifications on the time axis indicate the durations of stimulus presentation, additional response window and inter-trial-interval.