mysore have been studying the effects of this meditation on 120 students by measuring the associated increase of cortical thickness in the brain. the results of this study are inconclusive. vipassana meditation leads to more than just mindfulness, but has been found to reduce stress, increase well-being and self-kindness. these effects were found to be most powerful short-term, but still had a relatively significant impact six months later. in a study conducted by szekeres and wertheim (2014), they found stress to be the category that seemed to have the most regression, but the others contained higher prevalence when compared to the participants' original scores that were given before embarking on vipassana meditation. overall, according to self-reports, vipassana can have short and long-term effects on an individual. eeg studies on vipassana meditators seemed to indicate significant increase in parieto-occipital gamma rhythms in experienced meditators (35–45 hz). in another study conducted by nimhans on vipassana meditators, researchers found readings associated with improved cognitive processing after a session of meditation, with distinct and graded difference in the readings between novice meditators and experienced meditators. an essential component to the vipassana mediation approach is the focus on awareness, referring to bodily sensations and psychological status. in a study conducted by zeng et al. (2013), awareness was described as the acknowledgement of consciousness which is monitoring all aspects of the environment. this definition differentiates the concept of awareness from mindfulness. the emphasis on awareness, and the way it assists in monitoring emotion, is unique to this meditative practice. kundalini yoga kundalini yoga has proved to increase the prevention of cognitive decline and evaluate the response of biomarkers to treatment, thereby shedding light on the underlying mechanisms of the link between kundalini yoga and cognitive impairment. for the study, 81 participants aged 55 and older who had subjective memory complaints and met criteria for mild cognitive impairment, indicated by a total score of 0.5 on the clinical dementia rating scale. the results showed that at 12 weeks, both the yoga group showed significant improvements in recall memory and visual memory and showed a significant sustained improvement in memory up to the 24-week follow-up, the yoga group showed significant improvement in verbal fluency and sustained significant improvements in executive functioning at week 24. in addition, the yoga cohort showed significant improvement in depressive symptoms, apathy, and resilience from emotional stress. this research was provided by helen lavretsky, m.d. and colleagues. in another study, kundalini yoga did not show significant effectiveness in treating obsessive-compulsive disorders compared with relaxation/meditation. sahaja yoga and mental silence sahaja yoga meditation is regarded as a mental silence meditation, and has been shown to correlate with particular brain and brain wave characteristics. one study has led to suggestions that sahaja meditation involves 'switching off' irrelevant brain networks for the maintenance of focused internalized attention and inhibition of inappropriate information. sahaja meditators appear to benefit from lower depression and scored above control group for emotional well-being and mental health measures on sf-36 ratings. a study comparing practitioners of sahaja yoga meditation with a group of non-meditators doing a simple relaxation exercise, measured a drop in skin temperature in the meditators compared to a rise in skin temperature in the non-meditators as they relaxed. the researchers noted that all other meditation studies that have observed skin temperature have recorded increases and none have recorded a decrease in skin temperature. this suggests that sahaja yoga meditation, being a mental silence approach, may differ both experientially and physiologically from simple relaxation. transcendental meditation the first transcendental meditation (tm) research studies were conducted at ucla and harvard university and published in science and the american journal of physiology in 1970 and 1971. however, much research has been of poor quality, including a high risk for bias due to the connection of researchers to the tm organization and the selection of subjects with a favorable opinion of tm. independent systematic reviews have not found health benefits for tm exceeding those of relaxation and health education. a 2013 statement from the american heart association described the evidence supporting tm as a treatment for hypertension as level iib, meaning that tm "may be considered in clinical practice" but that its effectiveness is "unknown/unclear/uncertain or not well-established". in another study, tm proved comparable with other kinds of relaxation therapies in reducing anxiety. practitioners of tm have demonstrated a one hertz reduction in eeg alpha wave frequency relative to controls. research on unspecified or multiple types of meditation brain activity the medial prefrontal and posterior cingulate cortices have been found to be relatively deactivated during meditation by experienced meditators using concentration, lovingkindness and choiceless awareness meditation. in addition experienced meditators were found to have stronger coupling between the posterior cingulate, dorsal anterior cingulate, and dorsolateral prefrontal cortices both when meditating and when not meditating. over time meditation can actually increase the integrity of both gray and white matter. the added amount of gray matter found in the brain stem after meditation improves communication between the cortex and all other areas within the brain. meditation often stimulates a large network of cortical regions including the frontal and parietal regions, lateral occipital lobe, the insular cortex, thalamic nuclei, basal ganglia, and the cerebellum region in the brain. these parts of the brain are connected with attention and the default network of the brain which is associated to day dreaming. strengthening of the caudate has been found in avid meditators and yogis. in addition, both meditation and yoga have been found to have impacts on the brain, specifically the caudate. strengthening of the caudate has been shown in meditators as well as yogis. the increased connectedness of the caudate has potential to be responsible for the improved well-being that is associated with yoga and meditation. changes in the brain meditation is under preliminary research to assess possible changes in grey matter concentrations. published research suggests that meditation can facilitate neuroplasticity and connectivity in brain regions specifically related to emotion regulation and attention. attention/mind wandering non-directive forms of meditation where the meditator lets their mind wander freely can actually produce higher levels of activity in the default mode network when compared to a resting state or having the brain in a neutral place. these non directive forms of meditation allows the meditators to have better control over thoughts during everyday activities or when focusing on specific task due to a reduced frustration at the brains mind wandering process. when given a specific task, meditation can allow quicker response to changing environmental stimuli. meditation can allow the brain to decrease attention to unwanted responses of irrelevant environmental stimuli and a reduces the stroop effect. those who meditate have regularly demonstrated more control on what they focus their attention on while maintaining a mindful awareness on what is around them. experienced meditators have been shown to have an increased ability when it comes to conflict monitoring and find it easier to switch between competing stimuli. those who practice meditation experience an increase of attentional resources in the brain and steady meditation practice can lead to the reduction of the attentional blink due to a decreased mental exertion when identifying important stimuli. perception studies have shown that meditation has both short-term and long-term effects on various perceptual faculties. in 1984 a study showed that meditators have a significantly lower detection threshold for light stimuli of short duration. in 2000 a study of the perception of visual illusions by zen masters, novice meditators, and non-meditators showed statistically significant effects found for the poggendorff illusion but not for the müller-lyer illusion. the zen masters experienced a statistically significant reduction in initial illusion (measured as error in millimeters) and a lower decrement in illusion for subsequent trials. tloczynski has described the theory of mechanism behind the changes in perception that accompany mindfulness meditation thus: "a person who meditates consequently perceives objects more as directly experienced stimuli and less as concepts… with the removal or minimization of cognitive stimuli and generally increasing awareness, meditation can therefore influence both the quality (accuracy) and quantity (detection) of perception." brown points to this as a possible explanation of the phenomenon: " involves quieting some of the higher mental processes which normally obstruct the perception of subtle events." in other words, the practice may temporarily or permanently alter some of the top-down processing involved in filtering subtle events usually deemed noise by the perceptual filters. memory meditation enhances memory capacity specifically in the working memory and increases executive functioning by helping participants better understand what is happening moment for moment. those who meditate regularly have demonstrated the ability to better process and distinguish important information from the working memory and store it into long-term memory with more accuracy than those who do not practice meditation techniques. meditation may be able to expand the amount of information that can be held within working memory and by so doing is able to improve iq scores and increase individual intelligence. the encoding process for both audio and visual information has been shown to be more accurate and detailed when meditation is used. though there are limited studies on meditation's effects on long-term memory, because of meditations ability to increase attentional awareness, episodic long-term memory is believed to be more vivid and accurate for those who meditate regularly. meditation has also shown to decrease memory complaints from those with alzheimer's disease which also suggests the benefits meditation could have on episodic long-term memory which is linked to alzheimer's. calming and relaxation according to an article in psychological bulletin, eeg activity slows as a result of meditation. some types of meditation may lead to a calming effect by reducing sympathetic nervous system activity while increasing parasympathetic nervous system activity. or, equivalently, that meditation produces a reduction in arousal and increase in relaxation. herbert benson, founder of the mind-body medical institute, which is affiliated with harvard university and several boston hospitals, reports that meditation induces a host of biochemical and physical changes in the body collectively referred to as the "relaxation response". the relaxation response includes changes in metabolism, heart rate, respiration, blood pressure and brain chemistry. benson and his team have also done clinical studies at buddhist monasteries in the himalayan mountains. benson wrote the relaxation response to document the benefits of meditation, which in 1975 were not yet widely known. aging there is no good evidence to indicate that meditation affects the brain in aging. happiness and emotional well-being studies have shown meditators to have higher happiness than control groups, although this may be due to non-specific factors such as meditators having better general self-care. positive relationships have been found between the volume of gray matter in the right precuneus area of the brain and both meditation and the subject's subjective happiness score. a recent study found that participants who engaged in a body-scan meditation for about 20 minutes self-reported higher levels of happiness and decrease in anxiety compared to participants who just rested during the 20-minute time span. these results suggest that an increase in awareness of one's body through meditation causes a state of selflessness and a feeling of connectedness. this result then leads to reports of positive emotions. a technique known as mindfulness-based stress reduction (mbsr) displays significant benefits for mental health and coping behaviors. participants who had no prior experience with mbsr reported a significant increase in happiness after eight weeks of mbsr practice. focus on the present moment and increased awareness of one's thoughts can help monitor and reduce judgment or negative thoughts, causing a report of higher emotional well-being. the mbsr program and evidence for its effectiveness is described in jon kabat-zinn's book full catastrophe living. pain