Interactions between top-down attention and bottom-up visceral inputs are assumed to produce conscious perceptions of interoceptive states, and while each process has been independently associated with aberrant interoceptive symptomatology in psychiatric disorders, the neural substrates of this interface are unknown. We conducted a preregistered functional neuroimaging study of 46 individuals with anxiety, depression, and/or eating disorders (ADE) and 46 propensity-matched healthy comparisons (HC), comparing their neural activity across two interoceptive tasks differentially recruiting top-down or bottom-up processing within the same scan session. During an interoceptive attention task, top-down attention was voluntarily directed towards cardiorespiratory or visual signals.
View Article and Find Full Text PDFBackground: Reduced Environmental Stimulation Therapy (REST) is a behavioral intervention that systematically attenuates external sensory input to the nervous system. Previous studies have demonstrated acute anxiolytic and antidepressant effects of single sessions of REST in anxious individuals, however the duration and time course of these effects is unknown. In the current study, we used experience sampling and multiple sessions of REST to explore the time course of the anxiolytic and antidepressant effects over a 48-hour time period.
View Article and Find Full Text PDFInteractions between top-down attention and bottom-up visceral inputs are assumed to produce conscious perceptions of interoceptive states, and while each process has been independently associated with aberrant interoceptive symptomatology in psychiatric disorders, the neural substrates of this interface are unknown. We conducted a preregistered functional neuroimaging study of 46 individuals with anxiety, depression, and/or eating disorders (ADE) and 46 propensity-matched healthy comparisons (HC), comparing their neural activity across two interoceptive tasks differentially recruiting top-down or bottom-up processing within the same scan session. During an interoceptive attention task, top-down attention was voluntarily directed towards cardiorespiratory or visual signals, whereas during an interoceptive perturbation task, intravenous infusions of isoproterenol (a peripherally-acting beta-adrenergic receptor agonist) were administered in a double-blinded and placebo-controlled fashion to drive bottom-up cardiorespiratory sensations.
View Article and Find Full Text PDFAs the sense of the body's internal state, interoception represents the afferent component of the brain-body feedback loop essential for linking internal sensation with body regulation, thereby minimizing erroneous feedback and maintaining homeostasis. The anticipation of potential future interoceptive states enables organisms to take regulatory actions to meet demands before they arise, and alterations of anticipation have been implicated in the pathophysiology of medical and psychiatric conditions. However, laboratory approaches operationalizing the anticipation of interoceptive states are missing.
View Article and Find Full Text PDFGas-collection masks are used as a comfortable alternative to the traditional mouthpiece and noseclip during exercise testing protocols in human performance laboratories. However, these masks may introduce potential problems which could affect metabolic and ventilatory parameters, including gas leaks and added dead space. Therefore, the purpose of this study was to compare breathing mechanics, gas exchange variables and ratings of perceived breathlessness (RPB) during high-intensity exercise between a mouthpiece and face mask.
View Article and Find Full Text PDFHabitual endurance training may be associated with mild airway inflammation and subsequent deterioration in lung function. PCSO-524™ (Lyprinol®/Omega-XL®), a supplement extracted from the New Zealand green-lipped mussel (), has been shown to moderate airway inflammation in asthmatic subjects. The purpose of this study was to determine whether supplementation with PCSO-524™ improves pulmonary and respiratory muscle function in non-asthmatic elite runners.
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