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The stress-response
Published in Herman Staudenmayer, Environmental Illness, 2018
The major norepinephrine nucleus is the locus coeruleus, which is part of the medulla located in the midbrain. The LC has been shown to innervate both cortical and limbic areas directly involved in the perception and discrimination of meaningful and specifically fear-related stimuli (Wolfe and Chamey, 1991). Discharge of NE from LC-NE neurons plays a role in attentional vigilance, selective attention, and orienting responses (Aston-Jones et al., 1991a; Foote et al., 1991). Peripheral effects may result directly, or through the activation of the HPA-axis by stimulating the release of CRH in the PVN. LC-NE release may be related to the appraisal of an event and may have specific or generalized effects on the memory networks in certain contexts. The presence of NE can facilitate memory storage; its absence can lead to amnesia (Zornetzer and Gold, 1976). NE may also modulate the excitation or the inhibition produced by another neurotransmitter (Gold and Zornetzer, 1983; Zornetzer, 1978) and increase anxiety in clinical patients (Teicher, 1988).
Bodies in mind: using peripheral psychophysiology to probe emotional and social processes
Published in Journal of the Royal Society of New Zealand, 2021
Gina M. Grimshaw, Michael C. Philipp
The pupil is the opening in the eye through which light passes to the retina. The size of the pupil is controlled by two sets of muscles in the iris. Contraction of the sphincter muscle (under parasympathetic control) constricts the pupil, while contraction of the dilator muscle (under sympathetic control) widens it (see Wang and Munoz 2015, for further review of pupil physiology). Changes in pupil diameter affect vision: constricted pupils are optimised for visual acuity (i.e. sharp visual focus) whereas dilated pupils are optimised for visual sensitivity (i.e. detection of faint stimuli). The parasympathetic pathway mediates the light reflex, a rapid constriction of the pupil that occurs when light levels suddenly increase. The sympathetic pathway, in contrast, acts more slowly to dilate the pupil when people engage with important, interesting, or emotional stimuli (Hess and Polt 1964; Bradley et al. 2008). This pathway is under control of the locus coeruleus, a neural structure that plays an important role in alertness and waking via modulation of norepinephrine (Aston-Jones and Cohen 2005). In different experimental contexts, pupil dilation can be a physiological outcome of both cognitive effort (Kahneman and Beatty 1966; Einhauser 2017) and emotional arousal (Hess and Polt 1964; Bradley et al. 2008). Relative changes in pupil dilation can be measured with most eye-trackers, meaning that pupillometry can be easily integrated into lab-based experiments of visual perception (Sirois and Brisson 2014; Mathôt 2018).
Engaging the human operator: a review of the theoretical support for the vigilance decrement and a discussion of practical applications
Published in Theoretical Issues in Ergonomics Science, 2020
Alexis R. Neigel, Victoria L. Claypoole, Samantha L. Smith, Grace E. Waldfogle, Nicholas W. Fraulini, Gabriella M. Hancock, William S. Helton, James L. Szalma
Unfortunately, explanations of mind-wandering in vigilance fail to clearly explain how observers engage and disengage in vigilance tasks (Fraulini et al. 2017; cf. Barron et al. 2011). The underlying mechanism is not clearly discussed in this theory—although, there have been some recent attempts to link mind-wandering to neuroscientific findings. Recent work has linked attention and engagement to the production of norepinephrine in the locus coeruleus, a structure involved in brain activation and arousal (Gilzenrat et al. 2010; Mittneret al. 2016). However, it is difficult to claim that this is support for mind-wandering theory alone, given that the locus coeruleus has also been linked to reward, motivation and brain activation (Atzori et al. 2016; Simpson and Lin 2007). Furthermore, the locus coeruleus and norepinephrine systems are intertwined with the corticosteroid systems, which are critical in the biochemical regulation of energy demand and distribution (De Kloet 2004), and the histaminergic systems, which are related to alertness and fight-or-flight responses (Wada et al. 1991; Shan, Bao, and Swaab 2015). Ignoring the interconnectedness of these systems results in a biased representation of the role of the locus coeruleus in arousal and wakefulness. Thinking back to the studies of CBFV (i.e. Reinerman-Jones et al. 2011), and the mechanisms for restoring attention, it is equally possible that the release of norepinephrine in the locus coeruleus is interlinked with the modulation of alertness and energy distribution (Atzori et al. 2016; Simpson and Lin 2007), which aligns more closely with cognitive resource theory. And, from a neuroscientific perspective, it is likely that resources are a broad, emergent construct related to many brain areas (Langner and Eickhoff 2013).
A computational model of pupil dilation
Published in Connection Science, 2018
Birger Johansson, Christian Balkenius
The Locus coeruleus (LC) is involved in arousal and stress, including the processing of noxious stimuli. LC can influence pupillary constriction both by inhibition of the parasympathetic system and through sympathetic excitation (Szabadi & Szabadi, 2012).