Happiness promotes global processing in haptic perception

Happy and sad mood promote global and local visual processing, respectively. However, it is unclear whether mood also affects the processing level in haptic perception. Here, we used classical music to induce happy and sad mood in blindfolded participants before they scanned 3D-printed configurations with their fingers. Additionally, we included a neutral group who did not listen to any music. Global shapes were triangles, circles, or squares (33mm) composed of smaller local relief shapes (3 mm): either triangles, circles, or squares. Participants explored a probe stimulus with identical local and global shapes, and two comparison stimuli, matching the probe in local, or global shape. They reported which comparison stimulus appeared more similar to the probe. In the sad group, participants chose the locally matching comparison more frequently than in the happy and neutral groups, revealing that sad mood promotes local processing also in touch. Overall, participants chose the globally matching comparison more often, suggesting that global processing is more prominent in touch than previously assumed.