ABSTRACT
In order to better understand stress responses, neuroimaging studies have investigated the underlying neural correlates of stress. Amongst other brain regions, they highlight the involvement of the prefrontal cortex. The aim of the present study was to explore haemodynamic changes in the prefrontal cortex during the Maastricht Acute Stress Test (MAST) using mobile functional Near-Infrared Spectroscopy (fNIRS), examining the stress response in an ecological environment. The MAST includes a challenging mental arithmic task and a physically stressful ice-water task. In a between-subject design, participants either performed the MAST or a non-stress control condition. FNIRS data were recorded throughout the test. Additionally, subjective stress ratings, heart rate and salivary cortisol were evaluated, confirming a successful stress induction. The fNIRS data indicated significantly increased neural activity of brain regions of the dorsolateral prefrontal cortex (dlPFC) and the orbitofrontal cortex (OFC) in response to the MAST, compared to the control condition. Furthermore, the mental arithmetic task indicated an increase in neural activity in brain regions of the dlPFC and OFC; whereas the physically stressful hand immersion task indicated a lateral decrease of neural activity in the left dlPFC. The study highlights the potential use of mobile fNIRS in clinical and applied (stress) research.
Subject(s)
Brain/physiology , Neurovascular Coupling/physiology , Spectroscopy, Near-Infrared/methods , Stress, Psychological , Brain/diagnostic imaging , Female , Heart Rate , Humans , Hydrocortisone/metabolism , Male , Neuropsychological Tests , Saliva/metabolism , Young AdultABSTRACT
The OPMI operating microscope system for use in micro-neurosurgery is here described. Its various illumination systems, tubes, eyepieces, objectives and other accessories make it extremely versatile and it also offers excellent possibilities for documentation (photo, film, video). Furthermore, over and above its facilities for dual observation and assistants, it also enables two surgeons to work together during an operation. A variety of floor stands and ceiling mounts ensure that all requirements regarding mobility and economic use of space are fulfilled. Possible uses for CO2 and Nd-YAG lasers are also given.
