Basic Emotions

Fear is a powerful emotion which plays an important role in survival – fight or flight response.

Many fMRI (Functional magnetic resonance imaging) studies support the hypothesis that amygdala is the most important hub in a fear reaction (LeDoux, 1998).

Several aspects of fear processing have been attributed to the amygdala:

• fear conditioning (Davis, 1992; LeDoux, 2007),
• initiation of fear-induced behaviors in response to stressors, (Weiskrantz, 1956; Blanchard and Blanchard, 1972; Prather et al., 2001; Izquierdo et al, 2005; Machado et al, 2009),
• memory creation of fear-related stimuli (Cahill et al, 1995; Hamann, 2001).

Anger can be a particularly powerful emotion, characterized by feelings of hostility, agitation, frustration, and antagonism towards others.

Like fear, anger can play a part in your body’s fight or flight response.

Orbitofrontal cortex is the location for anger, because of its relation to prey.

Many fMRI studies suggest that the interaction between orbitofrontal cortex and amygdala is involved in the regulation of anger (Coccaro et al, 2007; Fulwiler et al, 2012).

Amygdala activity is related to initiation of fear, while the orbitofrontal cortex is involved in the fear extinction (Milad and Rauch, 2007; Siep et al, 2018).

Sadness: is an emotion caused by loss and helplessness (Motoki, Sugiura, 2018), or it is related to failure to get wanted thing (reward), or punishment to get harmful things (Gu et al, 2016).

Anterior cingulate cortex (ACC) is related to sadness (Godlewska et al., 2018; Ramirez-Mahaluf et al, 2018a,b). ACC is also linked to sadness because of its role in suffering; many studies have suggested that ACC is also involved in pain or suffering feeling and depression (Taylor et al, 2018).

The meaning of human life is associated to a large extent with the pursuit of happiness.

There are two different conceptions of happiness: hedonic happiness and eudaimonic happiness (Simeng Gu et al, 2019).

• Hedonic happiness is related to physical or psychological pleasure.
• Eudaimonic happiness is related to reaching personal goals or to expressing our potential, our abilities. (Berridge, Kringelbach, 2011).

Happy events from both kinds activate the ventral prefrontal cortex (including orbitofrontal cortex) (Kringelbach, 2005).

In a functional magnetic resonance imaging (fMRI) experiment, Rolls et al. (2008) found that activations in the ventral prefrontal cortex, the cingulate cortex, and the ventral striatum were associated with the positive hedonic state.

The emotion of disgust is typically experienced as a feeling of revulsion elicited by offensive stimulations, either in physical or moral respect.

There is no consensus among neuroscientists concerning the brain region responsible for disgust processing, as well as about the nature of this emotion itself.

Some researchers defend the opinion that the insula is the location of disgust processing and that it differs from anger and fear, while others, on the basis of meta-analysis of imaging data, found that the anterior insula is not more active during disgust processing than when processing other emotions, such as anger (Wager et al, 2007; Oaten et al, 2018a,b).

The surprise emotion alerts the individual of any deviations from expectations, regardless of the outcome value (Litt et al, 2011; Fouragnan et al, 2018).

According to meta-analyses of fMRI studies, surprise induced brain regions are predominantly subcortical, including the amygdala and striatum, as well as some cortical regions, such as the ventromedial prefrontal cortex and the cingulate cortex (Behrens et al, 2009; Bartra et al, 2013).