An international team of researchers explored how curved lines in interior design influence the brain’s sense of beauty. In a controlled experiment, seventy participants were shown one hundred photographs of indoor spaces that varied in curvature, from sweeping curves to sharp edges, while their brain activity was monitored with functional magnetic resonance imaging. After each image, participants rated the degree of curvature, the angularity of the forms, and the overall aesthetic appeal. The study aimed to connect perceptual experience with neural responses and to understand whether curved geometry carries a universal appeal across different cultures and settings.
Psychologists have long noted that curved and smooth lines tend to evoke more pleasant emotions than angular forms. This preference shows up in faces as well as in architecture, product design, and landscapes. The phenomenon appears across many ages and nationalities, and even among infants who respond positively to curved contours. Yet the same tendency is significantly weaker in individuals with autism spectrum disorder, a nuance that points to differences in how sensory information is processed in diverse neurotypes.
To gather diverse data, researchers recruited participants from several universities and regions, including Canada, Spain, Germany, and the United Arab Emirates. The experimental protocol presented 100 indoor images—half dominated by curved lines and half by straight, angular lines. During viewing, functional MRI measured brain activity, especially in areas linked to visual processing and reward. After each image, volunteers judged curvature, angularity, and the perceived beauty of the space. The design allowed scientists to compare neural responses to curved versus angular geometry while controlling for other variables like lighting, color, and perceived spaciousness. By correlating subjective ratings with brain activity, the team sought to determine whether beauty judgments for interiors recruit brain systems similar to those used to assess facial attractiveness.
Results showed clear evidence that the fusiform gyrus, a region well known for its role in recognizing faces, lit up when participants rated spaces with curved lines as beautiful. In other trials and for images with angular features, this area remained relatively quiet. The pattern suggests that the aesthetic appreciation of interior spaces may tap into the same neural coding that underpins the experience of facial beauty. The researchers emphasized that their conclusions are about correlations between perception and brain activity, not a direct measurement of conscious preference for one design over another. [Attribution: peer-reviewed study]
Beyond the lab, the findings offer designers and researchers a new lens on how spatial form shapes mood and social perception. Curved geometry might subtly communicate warmth and approachability, influencing how people feel in a room and how they interpret the people around them. The work also aligns with a broader view of beauty as a shared human experience tied to neural processing that evolved for social signaling. Future investigations could examine how other design elements, such as texture, material, and lighting, interact with curvature to modulate brain responses and real-world preferences. These insights reinforce the idea that small choices in interior geometry can have measurable effects on perception and wellbeing [citation].]