The experiments focused on how people process multiple facial expressions, a routine task that can help viewers identify emotional cues in complex social environments. Earlier behavioral work has found that faces in the central visual field contribute more strongly than peripheral faces when people explicitly judge an overall emotion, but it remained unclear whether central emotion has a special effect during faster, more automatic processing. The researchers addressed that question by arranging one central face with four surrounding faces and asking participants to perform tasks unrelated to judging their emotions. Across three experiments, the central emotion was associated with a shift in processing speed rather than a larger neural response.

Experiment 1 used a forward–reverse oddball design, which the researchers employed to control for physical differences among the stimuli. Twenty-four participants viewed displays containing one central face and four peripheral faces while making a central gender-detection judgment. The central face was either emotionally expressive—happy or surprised and congruent with the surrounding expressions—or neutral. Compared with the neutral condition, central emotional faces elicited an earlier vMMN latency, indicating that the change unfolded sooner. There was no significant difference in vMMN amplitude, the measure of response strength. This pattern led the team to describe the result as an acceleration effect of central emotion rather than an enhancement of the overall neural response.

The second experiment provided a single-face benchmark. Another 24 participants viewed isolated happy or surprised faces at fixation, without the surrounding ensemble of expressions. In this comparison, the multiple-facial-expression condition produced shorter vMMN latency than the single-emotional-face condition. The authors interpret this finding as evidence that the central face can influence the automatic processing of a broader expression ensemble. The result does not mean that viewers consciously recognized or judged the emotions more rapidly; instead, it concerns the timing of an automatic electrophysiological response measured while participants performed another visual task.

Experiment 3 tested whether the effect depended on the participants’ explicit gender judgment. The researchers replaced the central neutral face with a scrambled face and changed the task to detecting irrelevant colors, reducing demands associated with directly examining the central face. Twenty-four participants took part. The experiment replicated the earlier finding: displays with central emotional faces generated significantly earlier vMMN responses than displays with central scrambled faces. A consistent negativity bias also emerged across the experiments, with surprised faces producing earlier vMMN responses than happy faces. The authors characterized surprise as threat-related, but the supplied findings do not establish why the two emotional categories differed in timing. The study’s conclusions are also limited to the stimuli, college-student sample and experimental tasks used, so further work would be needed to determine how broadly the effect applies across people and emotional displays.

Subject of Research: EEG evidence that central emotional faces accelerate automatic processing of facial-expression ensembles

Article Title: Central facial emotion accelerates automatic processing of multiple facial expressions: An EEG study

Article References: Xiong, M., Ding, X., Hu, L., Liang, J., & Huang, Y. (2026). Central facial emotion accelerates automatic processing of multiple facial expressions: An EEG study. BMC Psychology. https://doi.org/10.1186/s40359-026-05505-2

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05505-2

Keywords: EEG, facial expressions, automatic processing, visual mismatch negativity, central vision, emotion, neural timing, social perception, Central, facial, accelerates, automatic