“…The latter term has mainly been used to describe responses such as cold-sweating (Cheung et al, 2011; Hemingway, 1944; Nobel et al, 2012; Sclocco et al, 2015) and pallor (Cassano et al, 1989; Kolev et al, 1997) that often occur following exposure to emetic stimuli, which are mediated through the sympathetic nervous system (Hammam et al, 2012). However, other physiological changes may be associated with the pre-emetic stress response, including alterations in heart rate variability (Doweck et al, 1997; Kim et al, 2011; Kim et al, 2005) and a release of vasopressin from the posterior pituitary (Fisher et al, 1982; Robertson, 1976; Rowe et al, 1979; Sorensen et al, 1985). Along with these physiological responses are a number of perceptions with accompanying behavioral changes (Graybiel et al, 1968; Muth et al, 1996), including an awareness that stomach emptying is imminent, loss of appetite (Farmer et al, 2015; Heer et al, 2006; Hiura et al, 2012; Lackner, 2014; Sanger et al, 2013), anxiety and foreboding (Coelho et al, 2015; Fox et al, 1988; Lackner, 2014; Tarbell et al, 2014), as well as lethargy and disinterest in engaging in routine activities (Graybiel et al, 1976; Lackner, 2014; Lawson et al, 1998; Matsangas et al, 2014; Van Ombergen et al, 2015).…”