Abstract: Recent research in embodied cognition suggests that bodily movements influence abstract cognitive processes, including aesthetic evaluation, through metaphorical associations. The focus of this study is on how horizontal hand movements affect facial aesthetic judgments and whether these embodied effects vary by gender. Building on the idea that directional movements are metaphorically associated with evaluative concepts, we hypothesized that enacting leftward movement would enhance aesthetic perception and decision efficiency compared with rightward movement. We also hypothesized that this effect would be more pronounced in female participants and that manipulating spatial reference points would modulate the approach-avoidance tendencies underlying the metaphorical mappings. facial attractiveness, horizontal hand movement, embodied metaphor, gender differences, drift diffusion model.
Three experiments were conducted with a study group of 143 right-handed Chinese university students, all with normal or corrected-to-normal vision and no history of neurological or psychological disorders. In each experiment, participants performed aesthetic judgments on facial images associated with varying levels of attractiveness while executing horizontal hand movements or key presses. All facial stimuli were selected from standardized databases and were uniformly processed. Electroencephalography data were recorded in all experiments using 64-channel electrode caps based on the international 10-20 system, and behavioral responses were collected using E-Prime software. The variables of the experimental design included the joint classification response condition and spatial reference position, while gender was treated as a between-participants variable. Data were analyzed using mixed-design analysis of variance (ANOVA), hierarchical drift diffusion modeling, and event-related potentials (ERPs) techniques to examine behavioral differences and their underlying cognitive and neural mechanisms.
The results supported our hypotheses. In the metaphor-congruent trials, participants responded more quickly and accurately in facial aesthetic judgments than in metaphor-incongruent trials, suggesting that directional motor actions facilitated aesthetic processing when aligned with metaphorical associations. Hierarchical drift diffusion model (HDDM)analyses further revealed that performing leftward movement increased drift rate, decreased the decision threshold, and shortened non-decision time, indicating more efficient evidence accumulation and less cautious decision-making. These effects were particularly pronounced among female participants, reflecting gender differences in embodied sensitivity. ERP data provided converging neural evidence: the N170 component showed greater amplitudes under leftward movement, indicating enhanced early-stage face processing; both EPN and P300 amplitudes were also elevated in metaphor-congruent conditions, reflecting stronger emotional engagement and evaluative motivation. Notably, gender differences were significant in some experiments, with female participants showing faster responses and stronger approach-oriented tendencies; however, in experiment 3, when spatial reference frames were manipulated to modulate approach-avoidance tendencies, this gender effect was strongly reduced, suggesting that contextual reference plays a regulatory role in embodied aesthetic processing.
In this study, we demonstrated that horizontal motor experience exerts an embodied influence on facial aesthetic processing, and that this effect varies by gender. Behavioral, computational, and neurophysiological evidence revealed that aesthetic judgments are shaped not only by visual input, but also by motor actions and their metaphorical associations. This study expands the understanding of embodied aesthetics and highlights gender differences in sensitivity to embodied cues. These findings have practical implications for product design, user interfaces, and marketing, especially when motion-based interaction influences evaluation. Optimizing embodied interaction design requires attention to individual differences, particularly gender.

Key words: facial aesthetic judgment, horizontal hand movement, embodied metaphor, gender differences, drift diffusion model