Rosemary oil is one of the more famous essential oils widely used in aroma-therapy. However, the effects of rosemary oil on the human body, in particular the nervous system, have not been sufficiently studied. This study investigates the effects of the inhalation of rosemary oil on test subjects’ feelings, as well as its effects on various physiological parameters of the nervous system. Twenty healthy volunteers participated in the experiment. All subjects underwent autonomic nervous system (ANS) recording. This consisted of measurements of skin temperature; heart rate; respiratory rate; blood pressure; evaluations of the subjects’ mood states; and electroencephalography (EEG) recordings in the pre-, during treatment, and post-rosemary inhalation periods as compared with control conditions. Our results showed significant increases in blood pressure, heart rate, and respiratory rate after rosemary oil inhalation. After the inhalation treatments, subjects were found to have become more active and stated that they felt “fresher”. The analysis of EEGs showed a reduction in the power of alpha1 (8–10.99 Hz) and alpha2 (11–12.99 Hz) waves. Moreover, an increment in the beta wave (13–30 Hz) power was observed in the anterior region of the brain. These results confirm the stimulatory effects of rosemary oil and provide supporting evidence that brain wave activity, autonomic nervous system activity, as well as mood states are all affected by the inhalation of the rosemary oil.

Visual evoked potential (VEP) is a technique used to assess the brain's electrical response to visual stimuli. The aims of this study were to examine neural transmission within the visual pathway through VEP testing in preschool children with autism spectrum disorder (ASD) and compare it to age-matched controls, as well as search for a correlation between the VEP parameters and the symptoms of ASD. Participants were composed of ASD children (9 males) and typically developing children (8 males and 4 females), aged between 3 and 5 years. Checkerboards were chosen as the pattern-reversal VEP. The clinical severity of ASD was assessed using the Autism Treatment Evaluation Checklist (ATEC) and the Vineland Adaptive Behavior Scales 2nd edition (VABS-II). Our findings demonstrated that children with ASD had significantly longer N145 latency compared to the controls. A longer N145 latency correlated with a higher score of ATEC within the sensory/cognitive awareness subdomain. In addition, a slower N145 response was also associated with a lower VABS-II score within the socialization domain. The correlation between longer VEP latency and abnormal behaviors in children with ASD suggests a delayed neural communication within other neural circuits, apart from the visual pathway. These lines of evidence support the possibility of using VEP, along with clinical parameters, for the assessment of ASD severity.

This study aims to investigate the effects of d-camphor inhalation on psychophysiological parameters among healthy participants. Twenty-four healthy volunteers participated in the trials. d-Camphor was administered to determine the effects on autonomic nervous system (ANS), central nervous system (CNS) through electroencephalography (EEG) recordings as well as psychological parameters through emotional states. EEG recordings were conducted based on 10-20 system and EEG band power was calculated by Fast Fourier Transformation (FFT). For data analysis, d-camphor was inhaled and compared with sweet almond oil as base oil. Paired t-test was employed to measure the oil inhalation. The findings indicated that d-camphor inhalation caused significant changes in ANS parameters, psychological parameters through emotional states and central nervous system (CNS) through electroencephalography (EEG) recordings. After d-camphor inhalation, systolic blood pressure, heart rate, and the respiratory rate decreased significantly. Relaxed and calm feelings increased significantly while active and stressed feelings decreased significantly. The power of the alpha wave over all the brain areas including left anterior, right anterior, center, left posterior and right posterior brain areas increased significantly. d-Camphor caused significant changes in psychophysiological parameters indicating its sedative effects.