Brain Wave Changes in the Prefrontal Cortex When Exposed to Varying Plant Types as Visual Stimuli

Visual stimuli from green plants have positive effects on mental health. This study aimed to compare human responses to varying plant types [live, artificial, two-dimensional (2D), and three-dimensional (3D) plant models] as visual stimuli. Thirty adults (age, 29.9 ± 11.5 years) viewed each plant form while an electroencephalography (EEG) measured their brain activity. Psychological responses were assessed using the semantic differential method (SDM). No significant differences were observed among visual stimuli; however, brain activity differences varied between male and female participants. Males who observed live and artificial plants had a higher relative alpha (RA) spectrum (RAS) and relative fast alpha (RFA) spectrum frequencies at Fp1 and Fp2 ( P < 0.05 and P < 0.01 vs. P < 0.05 and P < 0.01, respectively), indicating greater emotional stability. Similarly, male participants who viewed 2D models had higher RA and RFA frequencies at Fp1 ( P < 0.01, P < 0.01) and Fp2 ( P < 0.05, P < 0.01). Male participants who observed 3D models exhibited higher RA, RSA, and RFA frequencies at Fp1 ( P < 0.01). Live and artificial plants were deemed the most calming ( P < 0.01). Both sexes found live plants to be the most pleasant (males: P < 0.01; females: P < 0.05) and natural (males: P < 0.001; females: P < 0.01). Overall, alpha wave differences were not significant among plant types, and live plants elicited a trend toward emotional stability. These findings suggest that 3D plant models can be as effective as real plants in psychophysiological applications, indicating their potential benefits for enhancing mental health in urban environments.