Uncertainty and stress: Why it causes diseases and how it is mastered by the brain

“From a theoretical perspective, the difference between attainable states and goal states can be formalized by the so-called ‘Kullback Leibler (KL) divergence’ (Kullback and Leibler, 1951).”

“How exactly these procedures are executed is one of the most fascinating questions in neuroscience (Friston, 2010).”

“The brain’s architecture is hierarchically organized (Felleman and Van, 1991).”

“All of these long-lasting effects of persistently activated stress reactions are called ‘allostatic load’ (McEwen, 1998).”

“It has been shown that both perceptual inference and learning can be described as a minimization of free energy or the suppression of prediction errors (Friston, 2005; Rao and Ballard, 1999).”

“In the short run, increased vigilance or anxiety in a hostile environment may be adaptive; however, when the danger passes and the behavioral state and the changes in neural circuitry become chronic, which get ‘stuck’, such maladaptation may require an external intervention to get it ‘unstuck’, as is the case for chro…”

“It has been shown that both perceptual inference and learning can be described as a minimization of free energy or the suppression of prediction errors (Friston, 2005; Rao and Ballard, 1999).”

“In this mode, LC projections to cortical areas lead to enhancement of only the few parts of the cortex involved in a specific task (Aston-Jones and Cohen, 2005; Berridge and Waterhouse, 2003).”

“, 1983) – particularly at branching sites of the blood vessel system (Malek et al., 1999).”

“…(Carhart-Harris, 2018a), exemplified by findings of increased brain complexity/entropy (Schartner et al., 2017) and decreased modular differentiation (Petri et al., 2014), provides an iconic image of dysregulated global brain function under psychedelics, with the 5-HT2AR as the trigger point.”

“There is now a wealth of research in adults demonstrating that individual variability in neurobiological responses to stress is informed through the assessment of factors that shape perceptions and interpretations of stress [10, 179, 180].”

“This extended activation alters brain architecture in regions such as the PFC, amygdala, and hippocampus, which undermines adaptive regulation and coping (Peters et al., 2017).”

“…attentional bias toward threat (Hakamata et al. 2010), increased worry and self-related cognitions, dysfunctional learning about bodily states over time (Van den Bergh et al. 2017), and increased allostatic load leading to increased stress and mental illness (Peters et al. 2017, Sterling 2014).”

“…Castelfranchi, 2009; Stepp, 2009; Shemesh et al., 2010; Stepp and Turvey, 2010; Mossbridge et al., 2012; Dhar et al., 2013; Goel and Mehta, 2013; Bohm et al., 2016; De Berker et al., 2016; Katz and Springer, 2016; Peters et al., 2017; Wilson et al., 2017; Gagliano et al., 2018; Katz et al., 2018).”