Psychophysiological responses to tactile contact with hairy versus hairless plant leaves

Tactile contact with ornamental plants promotes human health and healing. However, the impact of touching plant leaves on emotional and physiological responses requires further investigation. This study examined how leaf surface texture, hairy versus hairless, influences human psychophysiological responses in 30 Chinese female participants, using these two leaf types as stimuli. Subjective perception was measured using the Semantic Differential (SD) method, and physiological responses were assessed through electroencephalogram (EEG), heart rate variability (HRV), and electrodermal activity (EDA). Results showed that hairless leaves significantly increased α wave values in the C4 channel, indicating more pleasant and relaxed emotional responses, whereas hairy leaves significantly increased γ wave values, suggesting enhanced attention and exploration desire. Hairy leaves significantly decreased HRV indicators (pNN50, pNN20) compared with hairless leaves, indicating reduced parasympathetic activity and heightened emotional arousal; conversely, touching hairless leaves was associated with stronger parasympathetic activity and more relaxed emotional states. Additionally, EDA was significantly elevated when touching hairy leaves, indicating stronger emotional arousal. Therefore, hairless leaves demonstrate better performance in tactile comfort and emotional regulation. These findings provide theoretical and practical guidance for tactile design of plant landscapes and plant selection in sensory gardens for the blind.