Browsing by Author "Grant, Shara Soyini"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Controlling for Acute Caffeine Intake in Cardiovascular Reactivity Research
    Grant, Shara Soyini (Virginia Tech, 2016-04-08)
    Caffeine substantially affects cardiovascular functioning, yet wide variability exists in caffeine control procedures in cardiovascular reactivity (CVR) research. This study was conducted in order to identify a minimal abstention duration in habitual coffee consumers whereby CVR is unconfounded by caffeine; Six hours was hypothesized (average half-life). Thirty nine subjects (mean age: 20.9; 20 Women) completed a repeated measures study involving hand cold pressor (CP) and memory tasks. Caffeinated and decaffeinated coffee were administered. The following CV indices were acquired during baseline, task, and recovery epochs prior to coffee intake, 30 minutes-, and six hours post-intake: Heart rate (HR), high frequency heart rate variability (hfHRV), root mean squared successive differences (RMSSD), systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), pre-ejection period (PEP), left ventricular ejection time (LVET), and total peripheral resistance (TPR). Results support the adequacy of a six-hour abstention in controlling for caffeine-elicited CVR changes. The current study contributes to methodological endeavors in psychophysiology. Further investigations are crucial in establishing ideal caffeine controls, which would promote increasingly valid and reliable cross-study results.
  • Thumbnail Image
    Multidimensional Cardioception and Trait Anxiety: Potential Clues from Baroreflex Sensitivity
    Grant, Shara Soyini (Virginia Tech, 2018-08-10)
    Interoception, the perception of the body's physiological state, is often studied in relation to emotion processing. Particularly, cardioception has been largely implicated in anxiety. Three related but distinct dimensions of interoception have recently emerged in the literature: sensibility (IS), accuracy (IAC), and awareness (IAW). Divergent findings regarding interoception and anxiety may result from lacking appreciation for interoceptive dimensions. Additionally, the role of cardiovascular afferent feedback in anxiety and interoception is largely unknown. Baroreflex sensitivity (BRS) has been implicated in interoceptive processes yet no known research directly measures this in relation to multidimensional cardioception. The present study aimed to assess the degree to which IS, IAC, IAW, and BRS predict trait anxiety at rest and during anticipatory anxiety. Results partially suggest increased IAC and BRS, but more variable IS and IAW in relation to trait anxiety. Overall, results show complex associations among factors, suggesting increased specificity among the constructs. Results highlight the importance of attention to construct validity and method variance in the study of interoceptive subdomains. Finally, the present study helps to pave the way for continued investigations concerning cardioception in enduring anxiety and the related role of the baroreflex in cardiac afferent processes.