Effects of Meditation on Cerebral Activity

Effects of Meditation on Cerebral Activity Doris L. Scheer Researchers at the University of Pennsylvania conducted the first functional neuroimaging study to demonstrate changes in cerebral activity during glossolalia (A.B. Newberg et al., 2006). It’s not difficult to find research on Buddhist practices such as meditation but few researchers have conducted studies on Christian practices such as glossolalia. In fact, this was the first time that researchers took brain images during this phenomenon. Glossolalia is a spiritual practice or a worship expression that is referred to as speaking or praying in tongues. This mental state induces a spiritual experience in which incomprehensible language is produced without control. It is known that the frontal lobes are involved in willful control of behaviors (Frith et al., 1991; Pardo et al., 1991). Therefore, it was hypothesized that glossolalia, associated with the perceived loss of intentional control, would be associated with decreased activity in the frontal lobes compared with singing. T he SPECT technique used in this study measures regional cerebral blood flow that correlates closely with cerebral activity (Newberg et al., 2006). CBF ratios were compared between the glossolalia and singing state using a paired t-test (Minitab Statistical Software, 2000). Several significant rCBF differences were found, and the brain images taken while speaking in tongues showed minimal activity in both the frontal lobes and language centers of the brain. This discovery leads us to question how they were even capable of producing this behavior. The Old and New Testaments of the bible says that this ability comes from the holy spirit—our means of communicating with god, but how these women were able to speak without using the region of the brain that controls speaking is a mystery that neuroscience is trying to uncover. The research design involved a nonexperimental method in which relationships are studied by making observations or measures of the variables of interest. This may be done by asking people to describe their behavior, directly observing behavior, and/or recording physiological responses. In all these cases, variables are observed as they occur naturally (p. 77, P.C. Cozby and S.C. Bates, 2012). In this study, cerebral activity during glossolalia and singing were compared by measuring the cerebral blood flow ratios between each state by using a paired t-test. Because the nonexperimental method allows us to observe covariation between variables, another term that is frequently used to describe this procedure is the correlational method. With this method, researchers examine whether the variables correlate or vary together (p. 78, Cozby and Bates, 2012). The laboratory experiment setting permits researchers to more easily keep extraneous variables constant, thereby eliminating their influ ence on the outcome of the experiment (e.g. distractions). However, it is precisely this control that leads to the artificiality of the laboratory investigation (rather than their natural setting such as church or home). Fortunately, when researchers have conducted experiments in both lab and field settings, the results of the experiments have been very similar (Anderson, Lindsay, Bushman, 1999). This is reassuring. For this study, researchers at the University of Pennsylvania recruited five Christian women between the ages of 38 and 52 years old who had been speaking in tongues for at least five years. In the Philadelphia community of Pennsylvania both men and women perform glossolalia but the number of women who practice glossolalia is substantially higher. The researchers also reported difficulty in finding experienced practitioners willing to perform glossolalia in a laboratory setting. Andrew B. Newberg et al. (2006) explains that while this complicates the statistical analysis, the number of subjects was sufficient to reveal statistically significant results (p. 70). First, they obtained informed consent which was approved by the Institutional Review Board and then conducted structured clinical interviews. After ruling out any psychological disorders, neurological or medical conditions, or medications that would affect cerebral function, subjects were given a pregnancy test before placing an intravenous cannula (IV) in one arm. In order for the participants to move freely during singing and glossolalia, they made sure to use a long IV line. In addition, researchers observed all subjects to ensure that both singing and glossolalia conditions were as similar as possible in terms of patient vocalization and motion. Subjects reported that the glossolalia was perceived to be non-voluntary. Throughout both conditions, the subjects were standing while moving both their arms and legs in a similar rhythmic manner. Consequently, no significant changes were observed in the motor cortex; however, the phonemic structure was different between the two condition s. After the first five minutes of singing, subjects were injected through the IV with 7 mCi of 99mTc-Bicisate, and then brought to the SPECT scanner for a 40-min scan after a total of 20 minutes singing altogether. Next, subjects returned to the same room to perform glossolalia for 20 minutes and then scanned for 30 minutes using the same imaging parameters. After the first five minutes performing glossolalia, the subjects had also been unobtrusively injected with 25 mCi of 99mTc-ECD fifteen minutes before the scan. The results were hypothesis driven so comparisons were only tested for the major structures of the frontal, temporal, and parietal lobes, as well as the amygdala, hippocampus, striatum, and thalamus (also referred to as regions of interest [ROIs] throughout the study). Results indicated that the data between the glossolalia and singing state revealed several significant rCBF differences (cerebral blood flow ratios). Researchers also reported significant decreases in the prefrontal cortices, left caudate and left temporal pole while there were increases in the left superior parietal lobe (SPL) and right amygdala (A.B. Newberg et al., 2006). A percentage change in CBF ratios had been calculated for each region and a laterality index (LI) representing the percentage difference between the right and left side was also calculated revealing a significant negative correlation (R=-0.90, P=0.03) between the singing and glossolalia thalamic LI. According to A.B. Newberg et al. (2006) this indi cated that the more the thalamic activity was asymmetric to begin with, the more the asymmetry reversed during glossolalia (p. 69). The author’s interpretation of the results suggests that this preliminary study has begun to elucidate the neurophysiological correlates of glossolalia. Changes in several brain structures suggest that there is complex brain activity during this unusual practice (p. 70, A.B. Newberg et al., 2006). According to the author, the present study is the first that they are aware of that has evaluated changes in cerebral activity during the practice of glossolalia. In regards to their hypotheses, they observed decreased activity in the prefrontal cortices during the glossolalia state (p. 70). This finding was clearly distinct from their previous study of meditation using the same imaging technique (Newberg et al., 2001). Neuroimaging studies have also shown increased frontal lobe activity during attention-focusing tasks (Frith et al., 1991; Pardo et al., 1991). The author found it interesting that the frontal lobes showed decreased perfusion during glossolalia which was consistent wit h the subject’s description of a lack of intentional control over the performance of glossolalia (A.B. Newberg et al., 2006). Furthermore, the left hemispheric structures appeared to have significant decreases that were not observed in the right hemisphere and the lack of a clear lateralization in the frontal lobes suggests that the expressive language parts of the brain may not be as directly affected by glossolalia as might be expected (p. 70, Newberg et al., 2006). The author had previously argued, and found, decreased activity in the SPL during meditation in which there is a described loss of the sense of self, however, glossolalia was not associated with a loss of the sense of self and there were no significant decreases in the SPL (p. 70). The author’s interpretation of the significant decrease in the left caudate is of uncertain significance but suggested that it may relate to the altered emotional activity during glossolalia (A.B. Newberg et al., 2006). Several implications for further research were provided based on potential confounding problems within the study. Although the author claimed that the number of subjects was sufficient to reveal statistically significant results, I think caution should be used when generalizing results with a sample size less than 30 (in this case, 5). In addition, all female subjects were recruited from the same local community. A researcher more interested in the external validity of the research might conduct nonexperimental research with a more diverse population and this study had a highly restricted sample (p. 86, P.C. Cozby and S.C. Bates, 2012). There are many advantages of the experimental method for studying relationships between variables but there are also disadvantages to experiments and many good reasons for using methods other than experiments; so, although laboratory experiments often have strong internal validity, they may often have limited external validity (Cozby and Bates, 2012). In addition, glossolalia was performed in a laboratory setting rather than a natural environment such as a home o r church where a field experiment might yield different results. Being in a more spiritually inductive environment may potentially deepen their ability to further immense themselves into an even deeper glossolalia state. Perhaps a more natural environment and longer session would alter the brain activity that was originally recorded in this study. It would also be interesting to study whether younger or older subjects would be capable of performing glossolalia with the same results found in this study of middle to upper aged women between 38 and 52 years old. The inclusion of male subjects who practice glossolalia as well as a more culturally diverse sample would also increase the external validity of the research. Previously, I briefly mentioned how laboratory experiments often have strong internal validity. What I was pleased to read in the study was how all subjects were observed to ensure that the two conditions (both singling and glossolalia) were as similar as possible (p. 68, A.B. Newberg et al., 2006). Subjects began by singing in the room, while standing, with her eyes closed, matching her condition during glossolalia. The same music was also used for both conditions. I think these were important things to take into consideration. To rule out any other variables, subjects were also tested for mental disorders, substance abuse, neurological and medical conditions, or if they take medications that would affect cerebral function prior to the study. Further evaluation of the quality of this study revealed that this study was in fact reported in a peer-reviewed journal (Psychiatry Research: Neuroimaging, 2006, Vol. 148(1), pp.67-71 [Peer Reviewed Journal]). The practice of glossolalia is di scussed in both the Old and New Testaments of the bible which has outlived every critic since the beginning of time yet it’s still common for religious studies to receive a lot of criticism. It was originally thought that glossolalia was related to some form of psychopathology; however, the limited number of reported studies have suggested that people who speak in tongues show no differences in personality traits from other population groups—no increases in depression, anxiety, mania, or psychosis (Hine, 1969; Richardson, 1973). In fact, a recent study of nearly a thousand clergy members revealed that 80% who practiced glossolalia had greater emotional stability and less neuroticism (Francis and Robbins, 2003). Perhaps the practice of glossolalia actually increased their emotional stability and decreased neuroticism. Clearly causation could not be inferred but if further research could address the limitations I discussed in the previous paragraph, there could be powerf ul implications. Therefore, based on my assessment of the strengths and weaknesses of this study I think it is very important. The results of this study revealed that the part of our brain that is used for speaking was not activated while speaking in tongues. This suggests that the ability to speak in tongues comes from something else deep within us, confirming what the bible teaches about this spiritual gift called glossolalia. The news story did a fairly good job conveying the substance of the empirical study. It reported a brief yet accurate description of the sample, procedure, and results of the study. As I’ve mentioned previously, Buddhist practices such as meditation has recently become a popular research interest but Christian practices such as glossolalia have not been given quite as much attention so it was interesting to see comparisons being made in both the study and news story. The author of the news story shined light on this subject by emphasizing how the new findings contrasted sharply with images taken of other spiritually inspired mental states like meditation, which is often a highly focused mental exercise, activating the frontal lobes (Carey, 2006). I would say that more details could have been incorporated into the news story but a link to the actual study was provided for those who were curious enough to dig a little deeper. The story basically just hit the important aspects of the study and major findings. Furthermore, there was a good match between the strengths of the study and the way that the story was reported. It was interesting how the author of the news story incorporated important insights from the leader of the study team that I did not recall reading in the study. For instance, â€Å"the amazing thing was how the images supported people’s interpretation of what was happening,† said Dr. Andrew B. Newberg, leader of the study team, which included Donna Morgan, Nancy Wintering and Mark Waldman. â€Å"The way they describe it, and what they believe, is that God is talking through them,† he said. Dr. Newberg is also a co-author of â€Å"Why We Believe What We Believe.† And Ms. Morgan, a co-author of the study, was also a research subject (Carey, 2006). This was information I did not gather from the study alone so I assume that interviews must have been conducted and incorporated into the news story which adds a lot of in sight useful in evaluating the research in its entirety. Some of the findings that might have been underemphasized included results from some of the four hypotheses that may not be considered significant enough to emphasize in the media report. For example, one finding underemphasized in the news story was that the researchers did not observe the hypothesized increase in thalamic activity and it was not clear what such a finding may represent from a physiological perspective (p. 70, A.B. Newberg et al., 2006). Again, I think the reporter made this particular choice because it didn’t necessarily support or impact the main point. References Carey, B. (2006, November 7). A neuroscientific look at speaking in tongues. The New York Times. Retrieved from http://www.nytimes.com/2006/11/07/health/07brain.html?_r=0 Cozby, P.C., Bates, S.C. (2012). Methods in behavioral research (11th ed.). New York, NY: McGraw-Hill. Newberg, A.B., Wintering, N.A., Morgan, D., Waldman, M.R. (2006). The measurement of regional cerebral blood flow during glossolalia: a preliminary SPECT study. Psychiatry Research. Neuroimaging 148 (1), 67-71.