Aplicaciones del compuesto Cu 2 ZnSnSe 4 como Capa Absorbente

Theories relating to the neurobiological basis of emotions have been formulated largely through neural mapping of the mammalian brain. This approach has traditionally explained human emotion as either a pleasant or an unpleasant mental state controlled within the limbic system. To understand human emotion regulation an appreciation of the basic neurobiological systems of brain processes relevant to emotion processing is important. Firstly, it is vital to appreciate that neurobiological regions located on the higher and lower neuroaxis in the brain apply mutual regulatory influences such that ‘a top-down’ and ‘bottom-up’ regulatory influence exist between them. ‘Top-down’ regulatory effects typically include influences from the prefrontal cortex to the amygdala, while ‘bottom-up’ influences typically include influences from the limbic system to higher cortical areas of the brain (Thompson, Lewis, &

Calkins, 2008). Cortical areas higher on the neuroaxis were previously thought to exercise inhibitory effects on lower limbic areas, but more contemporary neuroimaging evidence suggests that cortical and limbic areas operate complementarily in respect of responses to emotion related events (Kober et al., 2008). In a meta-analysis of 162 neuroimaging studies, Kober et al. (2008) reviewed participants responses to emotion-related tasks and reported that numerous frontal areas were found to co-activate with multiple limbic areas but with little evidence that the co-activations were of an inhibitory nature. Similar findings have been reported in other studies, e.g. (Ochsner et al., 2009). Taken together, what these findings suggest is that frontal area co-activation with multiple limbic areas do not solely influence emotional control, but also influence the recruitment of cognitive-perceptual processes relating to emotion activation (Lewis & Todd, 2007). In addition, the role of neuroaxis circuits which link the amygdala, limbic structures and the anterior cingulate areas of the brain also help explain the cingulate’s role in influencing emotional appraisals and self-regulatory processes (Cardinal, Parkinson, Hall, & Everitt, 2002). This neuroaxis circuit mechanism therefore suggests that emotion regulation should be regarded not solely an inhibitory process, but rather as a complex mechanism of activities often involving bidirectional associations between different emotion relevant regions and thereby reinforcing a systems perspective of how emotions may be regulated (Ochsner et al., 2009; Scherer, Bänziger, & Roesch, 2010). A second reason for appreciating the neurobiological systems basis of brain processes relevant to human emotion processing relates to known associations between neurobiological mechanisms and their influence on early life experiences including human developmental histories (Calkins & Hill, 2007). In that respect understanding the role of neural and neuroendocrine arousal systems and their association with emotion regulation is essential. For example, the maturation of neural and neuroendocrine arousal systems (known to be functional in new-born babies) during the early developmental years helps explain why diminishing emotional lability and increasing concurrent greater self-control is seen in a developing child (Gunnar & Vazquez, 2015).

Regarding the neurobiology of two commonly used emotion regulation strategies i.e. cognitive reappraisal and expressive (emotional) suppression, studies have demonstrated that cognitive reappraisal operates by activating areas within the prefrontal cortex which in turn acts to inhibit the amygdala (which is associated with negative emotions) (Ochsner & Gross, 2007; Ochsner et al., 2004; Phan et al., 2005). As with cognitive reappraisal, expressive (emotional) suppression similarly increases activation in the prefrontal regions particularly the dorsolateral and ventrolateral areas, but unlike cognitive reappraisal, expressive suppression does not inhibit activation of the amygdala (Goldin, McRae, Ramel, & Gross, 2008). The prefrontal cortex and amygdala are therefore important structures in the context of emotion regulation.

Studies have implicated the prefrontal cortex with specific emotion regulation pathways including rewards processing, bodily signals, top-down modulation, and social processing. The work of Rolls (1990, 1996, 2000) provides important insights into this reward processing role of the prefrontal cortex. Roll’s works suggests that the prefrontal cortex in concert with the amygdala function to learn and represent the relationships between new stimuli (known as secondary reinforcers) and primary reinforces such as food or drink. Central to Roll’s suggestions are that neuronal connections in the prefrontal cortex can detect variations in the reward value of learned stimuli and accordingly alter their response. The hypothesis underlying the role of the prefrontal cortex and bodily signals is the somatic marker hypothesis which builds on the James-Lange (1885) theory of emotions. The somatic marker hypothesis proposes that certain regions of the prefrontal cortex (in particular the ventromedial regions) processes emotional bodily feedback which guides decision-making in complex and uncertain human situations (Damasio, 1996). The suggested mechanism is that somatic markers which are physiological reactions provide signals for delineating which existing events have been previously associated with emotion- related consequences thereby enabling the individual to work through situations of uncertainty when required to, based only on the emotional properties of the existing range of stimuli. With regards to top-

down and bottom-up modulation of emotions, the prefrontal cortex has increasingly been recognised as vital and associations have been made between this area of the corticolimbic system with automatically or effortful intent to regulate emotional experience or expression (Gross & Levenson, 1997; Nunn , Frampton, Gordon & Lusk, 2008). At the neural level, studies have found that prefrontal areas together with the orbitofrontal cortex and anterior cingulate cortex are more commonly involved in emotion regulation with results generally favouring cognitive rather than attentional control (Ochsner & Gross, 2005). Activation of these same areas have also been shown to be associated with deactivation in other areas of the limbic system such as at the amygdala resulting in successful emotional down-regulation (Ochsner, Bunge, Gross, & Gabrieli, 2002). With regards to social processing in emotion regulation pathways, the medial prefrontal cortex has increasingly become an important focus of research, with a recent study implicating this part of the brain in mentalising during emotion processing and also outcome monitoring, both of which are important in emotion regulation (Amodio & Frith, 2006; Frith & Frith, 2006).