Rough Meanings: Cross-sensory correspondences linking surface textures with sound symbolism, colours, and emotions

Paper Title

Rough Meanings: Cross-sensory correspondences linking surface textures with sound symbolism, colours, and emotions

Publication Info

• Topic area: Cross-sensory correspondences in texture perception and their implications for interaction design.
• Keywords: Cross-sensory correspondences, Bouba–Kiki effect, surface textures, visuo-tactile interaction, emotion, colour associations, roughness, tactile exploration, multisensory HCI, microstructural design.

Background and Problem

• Problem / challenge: Prior research on cross-sensory correspondences has focused on macrostructures (e.g., shapes, object forms), leaving a gap in understanding how microstructural surface textures influence perception, emotion, and cross-sensory mappings.
• Significance: Understanding these correspondences can enhance the design of multisensory interfaces, enabling richer, more intuitive, and emotionally resonant interactions in HCI applications such as VR/AR, tangible interfaces, and assistive technologies.
• Motivation and related work: The Bouba–Kiki effect demonstrates robust crossmodal mappings between shape and sound symbolism, but its extension to microstructural textures remains underexplored. Advances in digital fabrication and haptic rendering make microtextured design feasible, yet a guiding framework is lacking for how these features influence cognitive and affective responses.

Solution

• Proposed approach: Investigating cross-sensory correspondences of microstructural surface textures varying in roundness and size, using a methodological framework to link tactile roughness with sound symbolism, colour, and emotion.
• Novelty:
  1. Empirical evidence linking microstructural texture features to high-level symbolic meanings (e.g., Bouba–Kiki associations) and affective dimensions.
  2. Demonstration of how visual input modulates tactile exploration and cross-sensory judgments.
  3. Design guidance for integrating tactile and visual cues with affective dimensions in multisensory interfaces.
• Procedure and key techniques:
  • Fabrication of 36 3D-printed textures varying in roundness and size.
  • Within-subjects study with 30 participants under tactile-only and visuo-tactile conditions.
  • Tasks included ratings of roughness, Bouba–Kiki associations, emotional responses (using the PAD model), and colour associations.
  • Analysis of applied normal force and exploration duration using a custom-built force-sensing platform.

Results

• Concrete findings:
  • Rounded textures were associated with Bouba, pleasantness, calmness, cooler colours, and higher brightness, while pointed textures were linked to Kiki, unpleasantness, arousal, warmer colours, and lower brightness.
  • Very fine microfeatures were often associated with neutral greys and muted emotional responses.
  • Visual input reduced perceived roughness, biased judgments toward Bouba, and enhanced participants’ sense of control.
• Advantage over baselines:
  • Extended the Bouba–Kiki paradigm to microstructural textures, showing systematic mappings at a finer scale.
  • Demonstrated how vision modulates tactile perception and exploration strategies, providing new insights into visuo-tactile integration.
• Experiments / evaluation:
  • Quantitative analysis of perceptual ratings, emotional responses, colour choices, and applied force.
  • Qualitative coding of participant strategies (e.g., sensory features, familiar experiences, valence).
  • Statistical tests included ANOVAs, Friedman tests, Wilcoxon signed-rank tests, and chi-square analyses.
• Limitations and future work:
  • Fixed block order may have introduced order effects.
  • Limited material diversity and lack of physical roughness measurements.
  • Force-sensing platform captured only normal force, missing frictional and dynamic interaction data.
  • Findings may not generalize to diverse user groups or real-world textures.

Summary

This study explored how microstructural surface textures varying in roundness and size influence cross-sensory correspondences, including Bouba–Kiki sound symbolism, emotional responses, and colour associations. Rounded textures were linked to Bouba, pleasantness, and cooler colours, while pointed textures aligned with Kiki, arousal, and warmer tones. Visual input reduced perceived roughness, biased judgments toward Bouba, and enhanced the sense of control. These findings provide a foundation for designing multisensory interfaces that integrate tactile and visual cues to convey material qualities and emotional meaning, with applications in VR/AR, tangible interfaces, and inclusive design.