Anxiety disorders include features of excessive fear and anxiety. Fear is the emotional response to the presence of a perceived or real imminent threat, and is associated with periods of increased autonomic excitability, while anxiety is the anticipation of a future threat and is associated with vigilance and muscle tension. Elevated levels of anxiety differ from adaptive fear and anxiety in that they become excessive or persist beyond appropriate periods ( APA, 2014 ).

Meditation can be defined as a mind-body integrative practice based on experiencing the present moment, with full and non-judgmental awareness of every moment ( Wallace, 1970 ; Fortney & Bonus, 2007 ; Hayes et al., 1999 ; Roca et al., 2019 ). It is a form of mental training that improves the psychological core of an individual and involves attentional and emotional states. There are several different practices, and the main ones include mindfulness meditation, mantra, yoga, tai chi, and chi gong ( Ospina et al., 2007 ; Burke, 2012 ). The mindfulness-based technique has received more neuroscientific attention and research, and is the practice of nonjudgmentally focused mindfulness of present-moment experiences, resulting in mindfulness and self-acceptance ( Hölzel et al., 2007 ; Hwang et al., 2017 ; Tang et al., 2015 ).

The practice of mindfulness meditation is an excellent adjunctive therapy for many ailments and an essential and primary means of maintaining overall health and well-being. Rather than being a fringe concept, meditation is now widely known and accepted as a mind-body practice that is seen as beneficial by the general public and the scientific community ( Fortney & Taylor, 2010 ; Marciniak et al., 2020 ; Salmon et al., 2004 ). Studies show solid results from the practice of meditation associated with reduced anxiety, increased affection, reduced recurrence of depression, improvement in chronic pain, positive effects in the treatment of tension headaches, smoking, psoriasis, hypertension, alcohol abuse, benefits in longevity and cognitive functions in the elderly, among others ( Fortney & Taylor, 2010 ; Chambers et al., 2008 ; Jain et al., 2007 ; Tang et al., 2007 ).

Physiologically, meditation and its state of relaxation are defined by a hypometabolic state of parasympathetic activation ( Fortney & Taylor, 2010 ). A study using an electroencephalogram monitored the meditative state, pointing to the appearance of theta waves, a decrease in frequency, and an increase in the amplitude of alpha waves ( Wallace, 1970 ). In addition, mindfulness-induced neuronal changes are likely to involve dendritic branching, synaptogenesis, myelogenesis, or even adult neurogenesis ( Tang et al., 2015 ). It is also possible that there is autonomic regulation and improvement of immune activity, resulting in neuronal preservation, restoration, or inhibition of apoptosis, decreased inflammation, reduced autonomic nervous system reactivity, increased telomerase activity, and increased levels of melatonin and plasma serotonin ( Ngô, 2013 ).

It is known that pathological anxiety states have part of their genesis in amygdala hyperexcitability, related to fear. Mindfulness meditation leads to decreased amygdala activity, with results found mostly in beginners ( Desbordes et al., 2012 ). An analysis of the functional connectivity of the frontal regions and the amygdala points out that a negative correlation occurs in individuals with anxiety, in which there is suppression of emotional responses. On the other hand, after practicing meditation, a positive correlation of the structures is observed, which involves the monitoring of emotions, understood as the conscious regulation of emotion ( Hwang et al., 2017 ; Kocovski et al., 2009 ; Tang et al., 2015 ). Still, the hippocampus is an organ related to memory and spatial navigation that also undergoes changes. In people with meditative routines, this area shows denser internal cell connections and increased gray matter ( Luders et al., 2015 ). Concomitantly, prefrontal activity improves in beginner meditators and is related to greater active cognitive regulation. On the other hand, experienced meditators may no longer use this prefrontal control since their acceptance posture in relation to the experience is already automated, demonstrating improved ascending processing, and the same occurs with the parietal cortex ( Hwang et al., 2017 ; Tang et al., 2015 ).

Thus, various brain structures can undergo changes after practicing mindfulness meditation: anterior cingulate cortex, concerned with self-regulation of attention and emotion; prefrontal cortex, related to the attentional state and emotion; posterior cingulate cortex, related to self-awareness; insula, related to consciousness and emotional processing; amygdala, related to emotional processing; and hippocampus, related to memory ( Desbordes et al., 2012 ; Luders et al., 2015 ; Tang et al., 2012 ; Tang et al., 2015 ).

Training to improve attention has the potential to be beneficial in multiple fields, as attention networks are essential for higher-order cognitive operations ( Fortney & Taylor, 2010 ; Hwang et al., 2017 ; Tang et al., 2015 ). In addition to the benefits already known about anxiety, meditation can be practiced by individuals with no meditative experience, helping not only with quality of life, but also with a greater ability to retain new information and learn more effectively ( Luders et al., 2015 ; Tang et al., 2007 ; Kabat-Zinn et al., 2017 ; Kwak et al., 2020 ).

Therefore, the aim of the present study is to evaluate the relationship of mindfulness meditation with cognition, considering contextual memory, attention, and executive functions in young adult individuals.

Regarding the demographic data, it can be observed that both in the control group and in the test group, there was no significant difference between the number of male and female participants, which exerts little influence on the result between groups, only with a predominance of female participants. With regard to age, both groups were close in their averages. The average age before 24 years is important because the prefrontal cortex, especially the middle frontal lobe, responsible for decision-making and processing speed, continues its maturation until 24 years of age, and the evaluated participants obtained values not exactly significant in tests that assess the middle frontal lobe (Stroop and Trial tests) ( Arain et al., 2013 ; Kandel et al., 2014 ).

Continuing with the screening tests, the mini mental state examination also did not reveal a significant difference between the means of the groups, with only 0.22 between the averages. The test for signs and symptoms of depression (BDI) showed that patients in the control group had slightly higher level scores. This test was not used to exclude participants, only to observe the coexistence of signs and symptoms of depression and anxiety. The averages of both groups show a predominance of signs and symptoms of moderate depression. Although anxiety was associated with the presence of moderate symptoms of depression, meditation practices were still able to reduce anxiety levels and improve cognitive aspects.

With regard to the stress test (LIPP), it can be noted that patients in the control group had 1 participant without signs of stress, 6 participants in the resistance phase, and 13 in the exhaustion phase. The participants in the test group, on the other hand, had 4 participants without signs of stress, 7 in the resistance phase, and 5 in the exhaustion phase. For the comparison between the groups to be acceptable, it is pointed out that the control group, with a greater number of participants, would naturally have more participants in stress. Proportionally, the control group obtained 95% with signs of stress and the test group 75%.

The LIPP was applied in order to understand how much stress influences the participants’ anxious state, and to try to identify the ability of meditation to change anxiety and improve cognitive functions even in the midst of a state of stress. It is also important to highlight that, due to the fact that the test group has more individuals without signs of stress, we can infer a pure action of meditation on the improvement of signs and symptoms of anxiety. Within the LIPP, one can also infer the predominance of symptoms, whether physical or psychological. The Control Group had 2 participants with a predominance of physical symptoms, and 17 with psychological symptoms, just as the Test Group had 3 participants with a predominance of physical symptoms, and 9 with psychological symptoms. These data indicate that, although the control group included more individuals in the exhaustion phase, which could influence the results, both groups exhibited the same predominance of psychological stress, allowing for a more accurate analysis of the outcomes.

Participants in this study had anxiety levels (initial BAI) calculated at an average score of 22.8125. After applying the one-month meditation program, with two 1-hour weekly meetings, with the integrated technique of mindfulness with proprioceptive activity (Soul-Sync Meditation), the individuals reached an average score of signs and symptoms of anxiety of 14.8125. It is demonstrated, in addition to the main objective of this study, that mindfulness meditation remains an effective complementary method for reducing anxiety levels. Even among a group of young participants, who ranged from 18 to 28 years of age, a period of life in which they are subjected to high loads of stress, pressure, and activities, these levels could be reduced in the search for emotional balance.

The Logical Memory test ( Wechsler, 1987 ) part 1 (ML-1) works with immediate memory, a test which was applied without asking the participant to intend to remember what would be read to him. This phase of the test works more specifically on attention, for which the prefrontal cortex is primarily responsible. Thus, in Figure 1 , in (c) one can notice the capacity of meditation to increase the participant’s attentional capacity, with significance (p = 0.0023), comparing the test group with the control group. In Phase 2 of Logical Memory (ML-2), applied thirty minutes after the first part, one works with late and incidental memory, in which the main pathways involved are the hippocampus and the temporal lobe. With that in mind, it can be noted that the applied meditation program, even though it was short-term (1 month), showed significant results. It is known that the neural networks of the prefrontal cortex are more recruited in beginning or short-term meditators, as they are the first pathways activated. In this study, we show that the cognitive tests that most focused on the prefrontal cortex (ML-1, ML-2, SPAN-f and SPAN-r) obtained the best results. And, again, in Figure 1 , in (d) there is a significant (p = 0.0414) difference between the test group’s ability to retain previously heard content compared to the control group.

It is known that long-term meditators experience great effects from meditative practice; however, results can also be achieved in the short term ( Tang et al., 2007 ; Hwang et al., 2017 ; Kwak et al., 2020 ). A longitudinal study demonstrated that just 5 days (20 minutes a day) of mind-body integrative training (IBMT) led to an improvement in conflict management. The images indicated greater activation of the anterior cingulate cortex during the resting state after 5 days of IBMT. Magnetic resonance data suggest that the practice leads to greater cortical thickness and increased white matter of the anterior cingulate cortex ( Tang et al., 2007 ).

Another study applied a 4-day intensive meditation program accompanied by magnetic resonance imaging before and after the intervention, in which an increase in the prefrontal cortex, anterior cingulate cortex, and dorsolateral prefrontal cortex was identified, demonstrating an improvement of induced attentional networks by short-term meditation ( Kwak et al., 2020 ).

With that in mind, it can be noted that the applied meditation program, even though it was short-term (1 month), showed significant results. It is known that the neural networks of the prefrontal cortex are more recruited in beginning or short-term meditators, as they are the first pathways activated. In this study, we show that the cognitive tests that most focused on the prefrontal cortex (ML-1, ML-2, SPAN-f, and SPAN-r) obtained the best results.

Both tests mentioned above also showed that the structures of the hippocampus and temporal lobe are used by the participant, especially ML-2. The hippocampus is an essential structure for consolidating new information and creating memories. Within a short period of meditation, our participants were able to recruit this structure. In the ML-2 test, the control group obtained an average score of 22.14, while the meditation group obtained an average of 25.06, demonstrating that meditation enables greater recruitment of hippocampal neurons together with the sharp attention associated with auditory temporal lobe activity.

Meditation is an ancient technique that is increasingly popular today. The study suggests that it mitigates the manifestations of a number of disorders, including anxiety, depression, substance abuse, eating disorders, and chronic pain, among others. It is an increasingly applied tool in psychotherapeutic programs ( Fortney & Taylor, 2010 ; Chambers et al., 2008 ; Jain et al., 2007 ; Tang et al., 2007 ; Wallace, 1970 ; Tang et al., 2015 ; Ngô, 2013 ).

The mindfulness meditation practice applied in this study suggests that short-term meditation is able to reduce the signs and symptoms of anxiety as well as improve cognitive aspects. The application of a 4-week program, with 2 weekly meetings of 1 hour, using the soul-sync technique, was able to reduce the anxiety levels of 93.75% of the participants, which involves structures such as the amygdala. In addition, LM-1, LM-2, Span-f, and Span-r showed significant results, demonstrating that mindfulness meditation can improve the performance of immediate and delayed attention, incidental contextual memory, as well as working memory, which involves structures of the prefrontal cortex frontalis, hippocampus, and temporal lobe.

The activation and modification of various brain areas contribute to the understanding that mindfulness meditation is capable of stimulating brain plasticity, leading to behavioral changes and a greater ability to deal with conflicts. Mindfulness is a technique that results in individuals having a greater state of peace, calm, and relaxation, greater personal acceptance, reflective capacity, self-control, and self-regulation.

It is observed that to achieve the functions of processing speed and decision making, which surround the middle frontal lobe, longer mindfulness meditation programs could provide better results. Therefore, future studies could examine other mindfulness techniques and varying durations to evaluate their effects on cognitive aspects, further reinforcing the importance of mindfulness practice for the population.