ABSTRACT
OBJECTIVE: Although about 1-2% of MRI examinations must be aborted due to anxiety, there is little research on how MRI-related anxiety affects BOLD signals in resting states. METHODS: We re-analyzed cardiac beat-to beat interval (RRI) and BOLD signals of 23 healthy fMRI participants in four resting states by calculation of phase-coupling in the 0.07-0.13 Hz band and determination of positive time delays (pTDs; RRI leading neural BOLD oscillations) and negative time delays (nTDs; RRI lagging behind vascular BOLD oscillations). State anxiety of each subject was assigned to either a low anxiety (LA) or a high anxiety (HA, with most participants exhibiting moderate anxiety symptoms) category based on the inside scanner assessed anxiety score. RESULTS: Although anxiety strongly differed between HA and LA categories, no significant difference was found for nTDs. In contrast, pTDs indicating neural BOLD oscillations exhibited a significant cumulation in the high anxiety category. CONCLUSIONS: Findings may suggest that vascular BOLD oscillations related to slow cerebral blood circulation are of about similar intensity during low/no and elevated anxiety. In contrast, neural BOLD oscillations, which might be associated with a central rhythm generating mechanism (pacemaker-like activity), appear to be significantly intensified during elevated anxiety. SIGNIFICANCE: The study provides evidence that fMRI-related anxiety can activate a central rhythm generating mechanism very likely located in the brain stem, associated with slow neural BOLD oscillation.
Subject(s)
Anxiety/physiopathology , Brain Waves/physiology , Brain/physiology , Cerebrovascular Circulation/physiology , Heart Rate/physiology , Magnetic Resonance Imaging/methods , Adult , Anxiety/diagnostic imaging , Anxiety/psychology , Brain/diagnostic imaging , Female , Humans , Magnetic Resonance Imaging/psychology , Male , Photic Stimulation/methods , Psychomotor Performance/physiology , Rest/physiology , Rest/psychology , Young AdultABSTRACT
BACKGROUND: Previous studies reported positive associations between perceived neighborhood greenness and mental health. There has been a focus on perceived neighborhood greenness at people's home environment or in general, but data are lacking on greenness at working places or other locations where they actually spend most of their time during their day. METHODS: This study investigated the perceived greenness of college students' home and study environments and its relation to mental health. An online survey collected data from 601 participants with a mean age of 24 years, living in or around and studying in the city of Graz, Austria. The perceived greenness at home and at university was assessed using questions on quality of and access to green space; mental health was measured with the WHO-5 well-being index. Uni- and multivariate regression analyses were used to analyze the data. RESULTS: The analyses revealed positive associations between perceived greenness at home and mental health as well as perceived greenness at university and mental health. This adds more evidence to the existing literature that perceiving the environment as green is positively related to better mental health. CONCLUSIONS: Future research will have to incorporate objective greenness measures as a means of controlling for the reliability of the measurements and investigate the effects of different environments people are exposed to over the course of a day.
