Hence, 11 articles were eligible and included in the current systematic review see the flow diagram in Figure 1. Even though researches suggest that meditation modulates brain activities associated with cognitive control, the neural mechanisms underlying the benefits of meditation are not completely understood.
Moreover, to our knowledge, this is the first review that explores if the neural networks modulated by meditation when participants were instructed to regulate their emotional response are different from those modulated when participants naturally react to the aversive stimuli.
Results: Searches identified papers, of which 11 were eligible for inclusion. Overall, these studies suggest that practices from the attentional category induce changes in brain structure and function, particularly in the dorsal anterior cingulate cortex which is possibly related to general processes of self-regulation, increased attention to thoughts and information entering decision-making process and to the body during action executioninsula linked to an enhancement of body awarenessdorsolateral prefrontal cortex associated with introspection and enhancement in metacognitive skillsand the default mode network.
OM practices characterize metacognitive processes in which one is trained to non-judgmentally monitor cognitive and emotional events, thus cultivating a detached awareness of experiences. In comparison to the control group, the meditation group showed greater activation of the right rostral middle frontal cortex and the right pars opercularis, reaching the insula anterior insulaafter intervention.
Amygdala There is another area of the brain that is changed through meditation: the amygdala. Research confirms that as the cortical thickness of the hippocampus grows in volume through meditation, gray-matter density increases and all of these important functions are nurtured.
Non-meditators: clusters encompassing posterior cingulate gyrus, caudate, occipital lobe and frontal pole presented reduced activation after the retreat.
Hence, MBSR helped participants recruit a prefrontal area that reached the insula, indicating the recruitment of top-down mechanisms when processing angry faces, even without explicit instructions to regulate responses.
Characteristics of the Included Studies Study Design Of the 11 included studies, six used experimental design, that is, assessed the effect of a meditation intervention in comparison with a control group.
Five of these studies assessed participants before and after the intervention Allen et al. All practices from the studies included in the current review fell under the attentional category and consisted of either FA or OM meditations Lutz et al.