Jonathan Hiller
← Field Notes

A Present Mind

51 min read

Jonathan W. Hiller. Department of Psychology, The College of Wooster, 2008–2009. Supervised by Dr. Gary Gillund. Recognized at the state level—one of four honors graduates that year.

Acknowledgements

I would like to thank Dr. Gary Gillund for your time, encouragement, and amazing ability to simplify my complicated and cluttered technique of communicating. This was a joyful process (aside from a few rough spots) because of you. I would like to thank the participants that sacrificed hours of time and mental effort for my study. The experimental portion of this study was extremely involved and would have been impossible without your dedication. I would also like to thank Steve Berg who directed me in my approach to studying a spiritual topic. I would like to thank you Mom and Dad and my wonderful family for your support in all I do. I cannot even begin to put into words…

Abstract

Mindfulness is a relatively novel area of study in psychological research; however, it shows promising advances in several areas of cognitive function. The current study investigated the effects of short-term mindful meditative sitting on the executive network of cognitive function using a pre-test/post-test method. 19 college-aged students with no prior meditative experience practiced meditative sitting 15 minutes per day for 18 days compared to a college-aged control group that did not participate in meditation. The study found that there were no interactions between whether or not the group received mindfulness training and improvement on three cognitive tasks; however, the experimental group significantly improved over time compared to the control group on all tasks. The results of the current study suggest that mindfulness positively affects the executive network of cognition.

Introduction

Meditation has proven to be an effective tool for eliciting positive changes in cognition, immune system function, blood pressure, self-reported stress, regional blood flow to the frontal lobes, clinical depression, anxiety, and overall affect (Alavi et al., 2001; Allen, Chambers, & Lo, 2008; Amaro, Barreiros, Kozasa, Leite, & Radvany, 2008; Anand, Biedebach, Fernando, & Jevning, 1994; Hankey, 2006; Ivanovski & Malhi, 2007; Segal, Teasdale & Williams, 2002; Teasdale, 2003) There are many different types of meditation including transcendental, concentrative, and mindful. Many of these types of meditation have been studied with varying results; however, the mindful state of awareness achieved through the practice of meditative sitting has shown promising improvements in cognition. Although mindfulness has been studied, it is still an extremely novel area of research in psychology. Though much of the research involving meditation has surrounded the topic of mindfulness, it is difficult to study because it has been defined in numerous ways.

Defining Mindfulness

Mindful meditation is a difficult subject to study because it is difficult to provide a concrete definition (Kabat-Zinn, 2003). Mindfulness itself is a very broad term that is interpreted many different ways. Definitions of mindfulness have been created in order to successfully use mindfulness forms of meditation in clinical studies (Abbey et al., 2004; Allen, Blashki, & Gullone, 2006, Astin, Carlson, Freedman, & Shapiro, 2006; Brown & Ryan, 2003; Hayes & Shenk, 2004; Hayes & Wilson, 2003; Kabat-Zinn, 2003; Segal, Teasdale, & Williams, 2002). Mindful meditation as a practice is said to enhance mindfulness. The effect of meditative sitting to enhance mindfulness in every day life is contingent on how mindfulness is defined. Generally, mindfulness is the act of focusing on the moment, free from expectations or judgments. Mindful meditation enhances the individual’s ability to focus on the present moment through concentrative breathing exercises. Kabat-Zinn is one of the most recognizable faces in the clinical field of mindful meditation. Kabat-Zinn created a method of therapy known as mindfulness-based stress reduction (MBSR) that has had great results in clinical tests (Bishop, 2002; Brown & Ryan, 2003; Kabat-Zinn, 2003). Kabat-Zinn gives a working definition of mindfulness as an awareness that emerges through the action of paying attention on purpose. He mentions that mindfulness is a non-judgmental view of the world as it unfolds (Kabat-Zinn, 2003). Kabat-Zinn points out that mindfulness is the fundamental core behind all forms of Buddhist thought and meditative practice. He reports that the goal of a mindful state is to let go of expectations, goals, and aspirations, and simply be intentionally present (Kabat-Zinn, 2003). Kabat-Zinn’s definition has held through many trials of psychological research studying his form of mindfulness therapy. Therefore, Kabat-Zinn’s definition stands as the most respected to date. Some critical aspects of this definition are supported in other psychological definitions. Hayes and Shenk (2004) recognize Kabat-Zinn’s definition as an appropriate first step to understanding the concept of mindfulness; however they note that using normal psychological terms to describe mindfulness can be rigid and limiting. They emphasize the importance of meditation as a method of understanding mindfulness without explanation. Kabat-Zinn also supports this claim and urges that researchers must be part of their experiments to fully understand what they are researching (Hayes & Shenk, 2004; Kabat-Zinn, 2003). The claim that researchers be a part of their experiment is contradictory to the normal procedures of scientific and psychological research; however the critical aspect of the participants’ belief makes it essential to have direction from a genuine source. Hayes and Shenk claim that meditators in many traditions are asked to be aware of every experience in the present and to seek to understand the difference between being conscious and the focus of consciousness (Hayes & Shenk, 2004). The idea of being conscious of every experience contradicts what the psychological community knows about the theories of attention. It is interesting that mindfulness is seen to enhance systems of attentional control even though the goal of mindfulness is not to concentrate on any one item or thought. Abbey and colleagues (2004) created a definition of mindfulness that contains two main components. They proposed that mindfulness is the self-regulation of attention on the present moment, as well as an orientation toward the moment characterized by curiosity, openness, and acceptance (Abbey et al., 2004). Abbey and colleagues recognized that it is not enough to be focused on the moment, but it is also crucial to approach the moment with a commitment to curiosity. A sense of curiosity allows the individual to accept feelings and sensations as they arise (Abbey et al., 2004). Astin, Carlson, Freedman, and Shapiro (2006) reiterated this claim of an interaction between attention and attitude. They proposed that mindfulness is defined by the three axioms of intention, attention, and attitude (Astin et al., 2006). The Abbey et al. (2004) and Astin et al. (2006) definitions are intriguing and elaborate on the phenomenon of mindfulness as an interaction between cognitive and emotional states. The interaction between emotion and cognition is maintained by Kabat-Zinn (2003) in addition to Eastern religious thought processes (Hanh, 1975). Hayes and Wilson (2003) propose that mindfulness is the act of distancing identity from language. They allege that mindfulness is the practice of training the mind to expand beyond the thoughtful interpretation of the moment, or to realize that many more functions of the mind occur in addition to the conscious experience of the moment. They claim the limiting, analytical, and avoidant functions of normal thought exist because humans are largely connected to a language of illness that does not allow for mental range and flexibility (Hayes & Wilson, 2003). Hayes and Wilson argue that mindful meditation is one of many techniques that evoke a state of mindfulness, distancing the individual from toxic thought. They argue mindfulness has led to a new understanding of suffering and has redefined the approach of therapy to psychiatric disorders. Definitions of mindfulness have been useful because they allow psychologists to study mindful meditation in a laboratory setting. Dr. Kabat-Zinn’s definitions of mindfulness are the most widely used by psychologists in research that involves mindfulness practice in form of meditative sitting. The Hayes and Wilson (2003) definition is difficult to apply to psychological research because it is not specific enough beyond the aspect of distancing oneself from language. Kabat-Zinn is credited with his ability to use his techniques of mindfulness in the laboratory setting. Therefore, the definition proposed by his research should be used. The definitions of mindfulness provided above are an important step to understanding this phenomenon; however, the definitions themselves do not allow for operational use. Kabat-Zinn has used his definition to create a functional MBSR program, but access to this program is limited for most people. Therefore, a practical operational definition to evoke mindful states of awareness is needed. Kabat-Zinn recognizes Eastern traditions such as Zen Buddhism as effective disciplines that facilitate his idea of mindfulness. Hanh (1975) described the ability of the individual to focus on the moment through following the breath as the most effective means of eliciting mindful states. Focus on the feeling of the breath passing in and out of the body, and maintenance of a non-judgmental mind are described by Hanh as the most effective tools to harness mindfulness. The guidance of the Kabat-Zinn’s definition as well as the pragmatic opportunities of Hanh’s definition can be combined to effectively use mindful forms of meditation in an experimental setting. Although definitions of mindfulness have significantly contributed to the understanding of this complex cognitive process, there are still facets of this phenomenon that cannot be explained. It is difficult to completely define what is happening during the process of meditation because it has largely been employed as a spiritual practice. Individuals sometimes experience intense spiritual feelings that have not been thoroughly understood in the field of psychology. However, the study of meditation in psychology has furthered the understanding of this fascinating state of human consciousness. The definitions of mindfulness have been used widely to develop therapy techniques. As with any novel form of cognitive manipulation, different forms of meditation have been extensively studied to investigate possible effects on symptoms of psychological disorders. Mindful Meditation as a Form of Therapy Depression and anxiety have been extensively studied in the meditation field because both stem from an inability to control thought patterns. Mindful meditation has been used as an effective means of therapy for both depression and anxiety (Carmona, Goldin, McQuaid, & Ramel 2004; Evans et al., 2008; Fernos, Furhoff, & Waendell, 2008; Lau et al., 2000; Segal, Teasdale, & Williams, 2003). These thought processes are referred to in the literature as rumination, and in many cases ruminative thought is directly affected by meditation. Evans and colleagues (2008) found that an 8-week mindfulness based program was an effective tool for reducing stress and overall anxiety symptoms in participants with Generalized Anxiety Disorder. The participants underwent an 8-week mindfulness-based cognitive therapy group course taken from the MBSR program developed by Kabat-Zinn. They experienced a decrease in anxiety, worry, and depressive symptoms. The mindfulness program was found to be an effective means of therapy for depression and anxiety. Carmona and colleagues (2004) discovered that an 8-week MBSR course significantly decreased obsessive thought patterns in people with lifelong mood disorders. They found that, as mindful mediation increased, ruminative thought patterns tended to decrease. The decrease in rumination accounted for positive changes in affect specific to anxiety, depression, and the need for approval (Carmona, Goldin, McQuaid, & Ramel, 2004). This demonstrates a direct link between the practice of mindfulness and the ability of the participants to control their thought processes. Lau and colleagues (2000) found that mindfulness-based cognitive therapy nearly halved relapse and recurrence rates in patients with a history of three or more depressive episodes. These episodes are usually brought upon by the introduction of a new obsessive thought pattern. The evidence to support the use of mindfulness for therapy continues; however, there is little research that investigates the effect of mindful meditation on performance on cognitive tasks. This is puzzling because the purpose of mindfulness forms of meditation is that of sustained attention. The use of mindfulness techniques to deter negative rumination confirms this. Physiology and Mindful Mediation Evidence from brain imaging and EEG scans shows that different meditative approaches change human physiology (Aftanas & Golocheikine, 2002; Alavi et al., 2001; Anand, Biedebach, Chan, Cheung, & Han, 2008; Barnes, Davis, Murzynowski, & Treiber, 2004; Bonus et al., 2003; Delmonte 1984; Dunn, Hartigan, & Mikulas, 1999; Fernando, & Jevning, 1996; Grossman, Niemann, Schmidt, & Walach, 2004; Hankey, 2006; Hayashi et al., 2001; Ivanovski & Malhi, 2007). Research of brain imaging techniques reveals that the frontal lobes are activated during meditative experience (Anand, Biedebach, Fernando, & Jevning 1996; Alavi et al., 2001; Amaro, Barreiros, Kozasa, Leite, & Radvany, 2008). EEG studies revealing increases in Alpha wave frequencies during meditation lead to the understanding that different meditative states are most likely forms of higher consciousness and not forms of relaxation (Aftanas & Golocheikine, 2002; Dunn, Hartigan, & Mikulas, 1999). The evidence that meditation leads to short-term neuronal changes in the frontal lobes suggests that meditation may induce testable cognitive changes over time. Dunn, Hartigan, and Mikulas (1999) found that the EEG comparisons of relaxation, concentration, and mindful forms of meditation suggested that meditation and relaxation are very different forms of consciousness. The researchers found a greater number of higher frequency waves (alpha and beta) in concentrative and mindful forms of meditation. They discovered that greater frequencies of lower waves (theta) were present in relaxation techniques. Although mindful and concentrative meditators were in a relaxed state, the EEG pattern suggested there were very different cognitive states (Dunn, Hartigan, & Mikulas, 1999). The distinction between the meditative and relaxed state is essential to understand the effect of meditation on cognition. The research by Dunn and colleagues (1999) adds to the understanding that meditation affects the brain in a very different way than relaxation. Bonus and colleagues (2003) investigated the effect of mindful meditation on immune and brain function. They found that, after an 8-week mindfulness training program, participants demonstrated altered brain function (Bonus et al., 2003). Specifically, the researchers discovered that the left-sided anterior portion of the brain was activated after meditation. The researchers concluded that short-term meditation produced demonstrable effects on brain function. Aftanas and Golocheikine (2002) used EEG scans to measure 20 Sahaja Yoga meditators before and after meditation. They found that the most focused activity was concentrated in the midline frontal and central regions of the brain. They observed theta and alpha wave increases. The researchers postulated that certain dynamics of the brain were switched off during meditation to allow the individual to focus attention and block unnecessary information (Aftanas & Golocheikine, 2002). They based this conclusion on an EEG physiological response and did not test the participants’ cognitive abilities; therefore the connection between physiological response and attentional control cannot be made with certainty. Amaro, Barreiros, Kozasa, Leite, and Radvany (2008) studied the effects of a Zen meditation retreat on fMRI imaging techniques. The retreat specifically stressed mindfulness forms of meditative practices. The study had low power because of the small number of participants, however the findings were promising. An fMRI of the participants after the retreat revealed increased activation in the anterior cingulated, right dorsolateral prefrontal, insular, occipital and parietal cortices. This particular study demonstrated the effect of mindfulness on brain function. Alavi and colleagues (2001) used SPECT scans to study regional cerebral blood flow during the complex task of meditation. Experienced Tibetan Buddhist meditators and a control group of non-meditators were examined for 30 minutes after a period of intense meditation. The researchers found that meditation was associated with increased activation of the frontal regions of the brain. The researchers found that the deeper the individual fell into meditation, the more likely the person displayed activation of the frontal lobes (Alavi et al., 2001). An interesting finding from the study was that activation of the frontal lobes correlated with a decrease of activation in the parietal lobes. This suggests the complex cognitive task of meditation enhances focus, but decreases spatial awareness (Alavi et al., 2001). Different forms of meditation have shown to increase cortical blood flow to the frontal lobes of the brain as well as increase higher frequency brain patterns in participants. The research suggests that there is a strong connection between different forms of meditation and frontal lobe function. Executive Cognition and the Frontal Lobes Meditation is shown to correlate with frontal lobe function. The frontal lobes carry out the executive functions of cognitive functioning. Executive functions refer to the brain’s ability to program, control, receive, process, store, and verify information it receives (Ardila, 2008). It is the brain’s critical thinking area. The executive network refers to the role of the frontal lobes in cognitive awareness that includes decision making, working memory, problem solving, sustained attention, and attention switching (Braver, Brown, Reynolds, & Stigchel, 2006; Braver, Gray, Green, & Yarkoni, 2005; Bruno, Givens, & Sarter, 2000; Cabeza, Fransson, Ingvar, Marklund, Nyber, & Petersson, 2007, Fuster, 2002). This fact has been demonstrated through neuroimaging studies where participants take part in complex cognitive tasks, as well as through observing the cognitive function in individuals with damage to the frontal lobes. Individuals with frontal lobe damage lose their ability to be independent, creative, and critically evaluate; however, long-term memory and perceptual skills remain intact (Coolidge & Wynn, 2005). Braver, Gray, Green, and Yarkoni (2005) conducted fMRI scans of participants involved in a dynamic decision task that required the participants to make short-term payoffs to accrue long-term gains. The researchers observed increases in the right lateral prefrontal cortex during the task (Braver et al., 2005). The researchers reasoned that frontal lobe activation was critical to impulse control and decision making. Braver and colleagues (2006) hypothesized that internal task switching was contingent on prefrontal cortex function. The researchers found that task switching had explicit links to frontal lobe function (Braver et al., 2006). An fMRI was used to scan the participants as they completed a random-cueing task-switching program. Cabeza and colleagues (2006) attained functional magnetic resonance images of participants during complex working memory, episodic memory, semantic memory, and attention tasks. The researchers found that working memory and attention were both highly correlated with frontal regions of the brain (Cabeza et al., 2006). Specifically, they found sustained activity for the working memory task and attention task because of the complex nature of the tasks themselves. That is, the working memory and attention tasks demanded more of the complex cognitive processes for longer periods of time. Many forms of meditation increase blood flow to the frontal lobes of the brain, and increase high frequency alpha-waves in the brain. Mindful forms of meditation are found to have similar results; however, this area of meditation is less studied in neuroimaging techniques. Mindful meditation is demonstrated as a complex cognitive task that enhances and generates different levels of cognitive awareness. Thus, regulated mindful meditative practice should display increased activity in the frontal lobes of the brain and therefore specifically enhance the executive network of cognition. The executive network has been studied through complex cognitive tasks that test one or more aspects of attention switching, decision-making, working memory, and sustained attention.

Mindful Meditation and Cognitive Tasks Mindful meditation is a relatively new concept that has recently gained a reputation as a testable measure. There have been few studies investigating the effects of mindful meditation on cognition through cognitive tasks; however, most of these studies have shown that it increases scores on attention tasks (Allen, Chambers, & Lo 2008; Baime, Jha, & Krompinger, 2007; Chan & Woollacott, 2007; Kilner, Ortner, & Zelazo, 2007; Sweet & Valentine, 1999). Very few studies have been conducted in which little difference was found in attention control for mindful meditation as an independent variable. Anderson and colleagues (2007) found that an 8-week MBSR program did not elicit improvements in attentional control relative to a control group in pre and post-test attention tasks. They did find that the participants responded positively to the MBSR program, as their reports of anxiety and depression significantly decreased. The researchers acknowledge that their data did not reflect most of the research involving mindfulness training and attentional control. They reasoned that the 10-minute meditation session preceding re-test may not have been sufficient time to educe the desired effect in newly trained mindful meditators (Anderson, Bishop, Lau, & Segal, 2007). Kilner and colleagues (2007) investigated the difference between a 7-week mindfulness training course and relaxation meditation training on attentional control and emotional contexts. The researchers found that mindfulness meditation reduced emotional interference when participants were faced with negative emotionally stimulating pictures. This finding is interesting and novel because the relaxation group did not have any effect. Therefore, the study showed that meditation was a complex cognitive task that differed from regular relaxation techniques. They found that mindful meditation was effective in improving cognition through reducing emotional interference (Kilner, Ortner, & Zelazo, 2007). Much of this negative emotional interference is detrimental to normal cognitive functioning, which supports the claim that mindful meditation elicits positive cognitive function. Sweet and Valentine (1999) used the Wilkins’ Counting Test to measure sustained attention in concentrative and mindful meditators. The researchers recruited 19 members of a Buddhist center that were described as either short-term (24 months or less) or long-term (25 months or more) meditators. The control group consisted of 24 advanced level college students. The researchers found that meditators in general displayed superior performance to the control group on the two sets of the sustained attention task (Sweet & Valentine, 1999). They did not find a difference in performance between the two distinct methods of meditation. Concentrative and mindful meditators did not display significant differences on the test overall; however, on one set of the test that involved an expectancy effect, there were differences between the two groups. The researchers used their findings to argue there was a large difference between concentrative and mindful meditation techniques, and that particular difference shows when a stimulus becomes unexpected (Sweet & Valentine, 1999). It was apparent that both groups of meditators were able to ignore distracting thoughts compared to a control group with no prior meditation training. Also, the results showed that long-term meditators displayed further increments in attention compared to short-term meditators (Sweet & Valentine, 1999). Chan and Woollacott (2007) studied the effect of concentrative and opening-up meditation on scores on the Stroop task as well as the Global-Local Letters task. The experimental participants were gathered from six meditation centers in the Berkeley area, whereas the control participants were gathered from the University of California, Berkeley and North Oakland Senior Center. Similar to mindful meditation, opening-up meditation was explained as the individual’s ability to expand awareness to feelings, thoughts, and sensations as they arise without judgment. The main focus of the study was to assess the interaction between the executive function of the brain and the concentrative technique of meditation. The researchers found that the meditation group performed significantly better on the Stroop task but not the Global-Local Letters task (Chan & Woollacott, 2007). The results gathered by Chan and Woollacott suggested that there were long-term increases in the efficiency of the executive attentional network (prefrontal cortex) through the practice of meditation; however, the orientation network (parietal cortex) was not improved through meditation (Chan & Woollacott, 2007). They reached the conclusion that meditation enhanced the participants’ ability to shift attention away from distracting stimuli. The most interesting observation from this particular study was that higher performance on the attention tasks was correlated with minutes of meditation per day rather than overall time spent meditating. Baime and colleagues (2007) compared two separate meditation groups to a control group in a test/re-test format with the Attention Network Test (ANT). One meditation group participated in an 8-week MBSR program that met one time per week for 3 hours, whereas the other group participated in a full-time 1 month mindfulness retreat and were experienced in concentrative meditation before the study. The control group was gathered from the University of Pennsylvania and surrounding community. The researchers found that at the first testing time, participants in the meditation conditions with prior concentrative meditation experience were more efficient at reducing interference and displayed faster reaction times (Baime, Jha, & Krompinger, 2007). Mindfulness training improved overall performance on specific conditions of the ANT (Baime, Jha, & Krompinger). Allen, Chambers, and Lo (2008) investigated the effects of intensive mindfulness meditative training on sustained attention, working memory, and attention shifting tasks in twenty novice meditators. Twenty control participants also participated in the test/re-test portion of the experiment but did not participate in the mindfulness training. The experimental participants completed a 10-day mindfulness retreat at Dhamma Aloka Vipassana Meditation Centre in Woori Yallock, Victoria, Australia. The Digit Span Backward (DSB) test was used to test working memory. The Internal Switching Task (IST) was used to measure attention shifting and sustained attention. Allen, Chambers, and Lo concluded that mindfulness training significantly increased scores on the DSB but did not significantly reduce reaction times on the IST from trial 1 to trial 2 (Allen, Chambers, & Lo, 2008). They argued that mindfulness increased sustained attention, but not reaction times to switching stimuli. They also concluded that mindfulness training significantly lowered depressive symptoms, reflective rumination, and negative affect. The positive effect on cognition could help explain the enhanced ability on the cognitive tests. The finding that mindfulness training increased working memory capacity was a novel finding and suggested that mindfulness can be used as a therapy for conditions associated with working memory deficits such as schizophrenia and post-traumatic stress disorder. The researchers suggested that further research investigate meditation with specific measurements of time because the researchers could only estimate how long the participant meditated each day. There is relatively little research on the cognitive effects of mindful meditation. This is alarming because mindful meditation is used widely as a therapeutic tool, and is viewed as a method of controlling attention. Studies demonstrate that mindful and other forms of meditation have significant positive effects on cognitive function through various brain imaging and cognitive task related studies. There is a great need to further investigate this higher form of consciousness and its effect on attention and memory.

The Current Study

Based on indications in prior literature, the current study investigated the effects of mindful meditation on three demanding cognitive tasks. Prior studies have shown an increased interest in mindfulness as a testable measure. However, many of the prior studies did not control the context and environment of the meditation itself. Also, much of the literature used participants that completed lengthy mindfulness-based interventions or had extensive backgrounds in meditation. In many situations, access to these mindfulness retreats is impossible due to physical and monetary constraints. Therefore, it is necessary to investigate the possible effects of short-term daily meditative techniques on the executive network of cognition in participants with no prior meditative training. The current study was structured similarly to the study by Allen, Chambers, and Lo (2008). Three cognitive tasks were used to test before and after effects of mindfulness training through meditative sitting. The hypothesis of the current study was that mindfulness training would produce significant increases in sustained attention with interference, attention switching, and working memory. These three areas of the executive network were tested using the Stroop Task, Working Memory Alphabetical Task, and Digit Letter Substitution Test. It was hypothesized that, with 15 minutes of mindful meditation per day for 18 days, scores on the three tasks of executive function would significantly increase. This hypothesis was largely based on the research of Sweet and Valentine (1999), Chan and Woollacott (2007), Baime and colleagues (2007), and Allen, Chambers, and Lo (2008).

Method

Participants

The current study was comprised of two specific groups of undergraduate college students from The College of Wooster. The experimental group consisted of 19 students (ages 18-22). There were 10 male and 9 female participants in the experimental condition. The control group consisted of 19 students as well (ages 18-22). There were 12 female and 7 male participants in the experimental condition. None of the participants had any prior experience with mindfulness training through meditative sitting.

Materials

Demographic Survey. The researcher included a short demographic survey to gather information about the participants. The survey gathered the participants’ age, gender, graduation year, and ethnicity. Digit Letter Substitution Task. The Digit Letter Substitution Test (DLST) is a speeded task that asks the participant to substitute letters for specific numbers according to the key at the top of the page. In the task presented to the participants, there were 9 random letters given values of 1 through 9. There were 9 rows containing 15 letters in each row with a maximum of 135 possible substitutions. The first row was used for practice and was not counted in the data. The individual scores on the DLST were calculated by how many individual substitutions the participants wrote correctly in 60 seconds. The Digit Letter Substitution Test was developed by Jolles, Houx, Boxtel, and Ponds (1995) as an alternative to the Digit Symbol Substitution Test (DSST) which is part of the performance section of the Wechsler Intelligence Scales (Boxtel, Breukelen, Elst, & Jolles, 2008). The process is very taxing on the individual and calls upon many executive functions such as mental flexibility, sustained and switching attention, psychomotor speed, and speed of information processing (Boxtel et. al., 2008). The test has high reliability statistics (r > .85). Carter and Ravizza (2008) recognized task switching as an important aspect of cognitive control. An fMRI of undergraduate college students showed that the left dorsolateral prefrontal cortex was used in rule shifting. The degree of function of the dorsolateral prefrontal cortex was correlated with performance on this particular task switching event. The DLST is a better alternative to test attention switching than the DSST because, in a study comparing the two, participants found the DLST easier to understand in instruction compared to the DSST (Agarwal & Natu, 1995). The DLST also has similar reliability to the DSST, which happens to be one of the most widely used tests of stimulus recognition. Working Memory Alphabetical Task. The Working Memory Alphabetical Task tests the participants’ ability to hear and recall a random list of letters, but also recall them in alphabetical order. The current study used a version of the test that consisted of 12 sequences of random letters. The first two sequences consisted of 2 letters, and the subsequent sequences increased by one letter every two sequences up to 7 letters. The first sequence was used as practice. The individual scores on the Working Memory Alphabetical Task were calculated by how many letters the participant correctly recalled in alphabetical order. Tests of working memory capacity are complex cognitive processes of frontal lobe function that include maintenance of information as well as the ability to block unnecessary distractions (Cabeza et al., 2006; Coolidge & Wynn, 2005). The version of working memory capacity used in the current study was a variation of the Working Memory Index used in the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III; Wechsler, 1997). The working memory index on the WAIS-III is calculated using digit span and letter-number sequencing. The Working Memory Alphabetical Task is a version of alphabetical sequencing that is similar to the WAIS-III sequencing task. Stroop Task. The Stroop task (Stroop, 1935) is a frequently used test of attention and interference that records the participant’s ability to accurately read colors as quickly as possible. There are two separate tasks that comprise the Stroop. The first is a control portion that features 5 groups of 7 consecutive “X’s” across one row. The groups of “X’s” were colored in red, blue, green, and yellow. The participant was scored based on how fast he or she named the colors across the groups and rows. The number of errors was counted as the participant read. There were 10 rows in total in this particular Stroop task with the first row used as practice. The second portion of the Stroop task is considered the experimental portion. The experimental condition used words of colors instead of groups of “X’s”. However, the words did not match the color of the font. For example the word “green” may appear in red font. There were 10 rows of 5 words per row. The first row was used as practice. The participant was scored on the time to name the colors in the entire list. The errors while the participant read were also recorded. The Stroop color-naming task (Stroop, 1935) is valid and reliable test of cognitive flexibility and control (Bugg, Jacoby, & Toth, 2008; Cohen, Dunbar, & McClelland, 1990; Hessels, Lindsay, & Jacoby, 2003). The participant must be able to call upon higher order executive control to activate color naming and ignore word recognition in the inconsistent condition. The Stroop task demands multiple levels of attentional control, which relates to the executive network of cognition (Bugg, Jacoby, & Toth, 2008). The task seems simple; however there have been over 1,000 articles published on the robust interference effects found in the Stroop task (Bugg, Jacoby, & Toth, 2008). Meditation Instructions. The participants in the experimental group of the current study were given instructions at the beginning of each meditative sitting session. The instructions were given in the form of a paragraph describing the posture they were required to maintain and specifics on the nature of their mental focus during the session. Ten days after the sessions began, the paragraph included only the mental focus section and excluded instructions on posture. The paragraph instructed the participant on correct posture for sitting that is specific to evoking mindfulness. An example of correct posture taken directly from the paragraph is “Your back should never touch the back of the chair. Your back must be straight but relaxed (the posture that you stand with, but while sitting down).” The specifics on posture were based on suggestions from a local practicing Zen Buddhist. Correct posture is essential for evoking mindful awareness (Hanh 1975). The instructions also were specific to what the participant should focus on during the session. The “mind-focus” section of the instructions was based on Zen mindfulness philosophy and the basic themes of MBSR as explained by Kabat-Zinn (Kabat-Zinn, 2003; Hanh, 1975). The instructions focused on non-judgment of the current situation, as well as breath awareness. The last paragraph of the instructions encouraged participants to count their breaths from 1 to 10 and repeat the cycle. The paragraph encouraged the participants to use imagery in their quiet breathing. An example from this section of the paragraph is, “Count the breath each time you inhale, imagining the air coming from the tip of your nose down through your body to your naval. Exhale from the naval to the tip of your nose.” Focusing on the breath is a Zen technique that allows the individual to calm the mind in order to evoke mindfulness (Hanh, 1975).

Procedure

The current study was broken into different time periods. Most of the participants in the experimental group experienced exactly 18 days in the condition, whereas the control group tested between 17 and 21 days after the initial testing. Some of the participants in the experimental group did not participate in every formal meditation session; however, the participants communicated to the researcher that they had independently completed the mindful sitting. It was assumed in the data that the participants were reliable and completed the sessions. The participants in the experimental group were gathered using a social networking website called Facebook. It was believed that given the magnitude of the commitment it would be difficult to gather random participants. Therefore, participants were selected from a list of the researcher’s friends on the networking site. Once the participants were recruited, communication occurred via email. The control participants were recruited in the same way. On the first day of testing, the researcher divided the experimental group into blocks of 5 participants or less throughout the entire day. The participants signed a letter of informed consent. The researcher read specific instructions to the group directly from a testing prompt, and instructed the participants to complete the Digit Letter Substitution Task. The group completed the first row of substitutions as practice. Upon completing the practice row, the participants began the rest of the test on the researcher’s cue. The researcher also used this format for the Working Memory Alphabetical Task. The researcher read instructions for the Stroop task to the entire group; however, the participants completed the task individually because the reading time for each participant was recorded. After the three tasks were completed, the experimental group participated in the first 15-minute meditation session. The researcher gathered chairs in a circle and handed out the mindful mediation instructions to read. The researcher was an active participant in the meditation itself for every session. The only instructions given by the researcher were those read from the paragraph by the individual participant. The researcher observed the time via a stopwatch situated on the researcher’s chair. The experimental group was scheduled every day to complete the 15-minute session for 18 consecutive days. The participants were blocked together in groups of approximately 5, three times per day. The researcher set up additional times for participants who were unable to schedule the time or particular day. On the 18th day of testing, the experimental group was divided into blocks of 5 or less, and tested throughout the day. The groups completed one last 15-minute meditation session before beginning the cognitive tests once again. The participants completed the DLST, Working Memory Alphabetical Task, and Stroop task after they completed the last meditation session. The researcher gave the group 5 minutes between the end of the meditation session and before the start of the post-test. The researcher administered the tasks in the exact format as pre-test. The participants completed a short demographic survey after all of the cognitive tasks were completed. The researcher debriefed and thanked the participants for their time and willingness. The control group signed a letter of informed consent and received specific testing instructions on the DLST, Working Memory Alphabetical Task, and Stroop task in the same manner as the experimental group. These instructions were read to each participant as they completed each test in both the pre-test and post-test settings. Some of the control participants tested in groups of up to four, whereas others tested individually depending on the participant’s scheduling. The instruction format was consistent between the two groups. The participants completed each task in the pre-test as the researcher instructed, and were then permitted to leave. The final test was conducted 17 to 21 days later. The control participants arrived and re-tested on the three tasks once again. The same exact procedure was used in each case. The researcher debriefed and thanked the control participants. Some of the participants did not test on the 18th day because of scheduling issues; however, the researcher attempted to have the participant test as close to the 18th day as possible.

Results

The first hypothesis examined was that the experimental group would improve more than the control group on the Digit Letter Substitution Test over time. Scores on the Letter Digit Substitution test were calculated by how many substitutions the participant correctly completed in sixty seconds. The highest possible score was 120 and the lowest 0. To analyze the first hypothesis, a 2 x 2 mixed ANOVA was used with the condition of the group as the between subject variable and the time of the test given as the within subjects variable. Figure 1 presents the mean scores of the control and experimental groups over time. There was no significant main effect for group on Letter Digit scores, F(1, 36) = .038, p = .847. There was a main effect found for time on scores of the Letter Digit Substitution Test, F(1, 36) = 16.841, p < .05. There was no significant interaction between time and the groups, F(1, 36) = 3.384, p = .074. However, the interaction was suggestive. Also, the control and experimental groups did not begin at the same levels in the pre-test, so changes were a bit difficult to compare. Therefore, a paired t-test was used to compare the improvement for each group separately. The control group did not significantly improve between pre-test (M = 43.95) and post-test (M = 45.21), t(18) = -1.629, p = .06. However, the experimental group did significantly differ between pre-test (M = 42.53) and post-test (M = 45.84), t(18) = -4.133, p < .01. This suggests that the experimental group improved more that the control group. Caution is warranted here because the effects are not large. SHAPE * MERGEFORMAT Figure 1. DLST Scores as a Function of Group and Time The second hypothesis of the experiment was that the experimental group’s scores on the Working Memory Alphabetical Task would increase over time. Specifically, the scores on the working memory task would increase more for the experimental group than the control group. The scores were calculated by how many letters the participant recalled in alphabetical order. The highest score possible was 52 and 0 was the lowest score possible. Another 2 x 2 mixed ANOVA test was used with the condition of the group as the between-subjects variable, and the time of the test as the within-subjects variable. Figure 2 presents the mean scores of both groups over time. There was no significant main effect of group on working memory scores, F(1, 36) = 3.611, p = .065. These statistics suggest a trend toward significance, however there was no significant main effect for time on working memory scores, F(1, 36) = .140, p = .140. There was no significant interaction between time and group association, F(1, 36) = 3.823, p = .058. The interaction between group and time for working memory scores did approach significance. Therefore, the trends suggest an effect. It is important to note that the experimental and control groups did not score the same on the pre-test phase. Again, a paired t-test was used to examine improvement. No significant difference was found between the means of the control group between pre-test (M = 38.79) and post-test (M = 38.58), t(18) = .328, p = .38. However, there was found to be a significant difference in the means of pre-test (M = 40.58) and post-test (M = 42.21) in the experimental group t(18) = -2.368, p < .05. The difference in means suggests that meditation did have an effect on this particular task. This leads to the conclusion that the second hypothesis was at least partially supported. SHAPE * MERGEFORMAT Figure 2. Working Memory Scores as a Function of Group and Time The third hypothesis was that both groups would show improvement on the amount of time it took them to read through the stimulus. That is, it was hypothesized that interference would decrease on the task for both groups, as well as a greater reduction of time in the experimental group compared to the control group. The amount of time it took the participant to read the stimulus was the main variable measured. The time was calculated by the participant’s ability to verbally read through the entire list of grouped x’s or words as fast and as accurately as they could. The scores on the Stroop Task were calculated by subtracting the scores on the consistent condition from the scores on the inconsistent condition. Therefore, smaller scores would be equal to less interference, and better performance, on the task. A mixed 2 x 2 ANOVA was used with the condition of the group as the between-subjects variable, and the time of the test as the within-subjects variable. A paired t-test was used to compare the mean scores of interference for the task for both groups between pre-test and post-test. Figure 3 presents the mean scores of interference of both groups over time. There was no significant main effect of group on interference on the Stroop Task, F(1, 36) = .004, p = .950. There was a significant main effect of time on the Stroop Task F(1, 36) = 4.482, p < 0.05. There was improvement over time. There was no significant interaction between time and group F(1, 36) = .388, p = .537. This interaction shows no trends toward significance; however the groups did not begin with the same amount of interference. Therefore, a t-test was used to investigate possible differences in scores between the two groups. The paired t-test revealed that there was no significant difference in the control group means between pre-test (M = 14.06) and post-test (M = 12.797), t(18) = 1.068, p =.15. The test did find that there was a significant difference in the overall means of interference between pre-test (M = 14.509) and post-test (M = 12.188) for the experimental group, t(18) = 1.917, p = .035. The data tend to support the third hypothesis. The main effect of time shows that both groups performed better in the post-test, and the t-tests show a significant difference in overall means for the experimental but not the control group. The differences in scores suggest a small effect of mindful meditative sitting on scores of the Stroop task. SHAPE * MERGEFORMAT Figure 3. Stroop Interference Scores as a Function of Group and Time

Discussion

The goal of the current study was to investigate the effect of mindful meditation on three specific cognitive tasks. Experimental participants completed mindfulness training through meditative sitting for 15 minutes per day for 18 days. Control participants did not participate in meditation, but completed the three cognitive tests in a pre-test and post-test format after 18 days. Based on Sweet and Valentine (1999), Chan and Woollacott (2007), Baime and colleagues (2007) and Allen, Chambers, and Lo (2008), it was hypothesized that mindfulness training through meditative sitting would improve scores on the Digit Letter Substitution Task, the Working Memory Alphabetical Task, and the Stroop Task from pre-test to post-test. The study partially supported this hypothesis, as the means of the participants in the experimental group had significantly improved from pre-test to post-test on all of the tests. The control group did not significantly improve on any of the tests. The findings suggested that there was a positive impact on the executive network of cognition through mindfulness training. The effect in the present study was small; however, the trends suggested a connection between meditation and performance. The results of positive effects of mindful meditation on cognition demonstrated in the current study are largely consistent with prior research (Anderson et al., 2007; Baime, Jha, & Krompinger, 2007; Chan and Woollacott, 2007), although not to the degree initially expected. The participants’ average scores in the experimental condition significantly increased on the Digit Letter Substitution Task. The DLST is said to be an attention switching task, which leads to the conclusion that mindfulness training tends to increase one’s attentional ability. This result is largely consistent with the prior research investigating mindfulness and reduced interference in reaction time (Baime, Jha, & Krompinger, 2007). However, Anderson and colleagues (2007) and Allen, Chambers, and Lo (2007) found that mindful meditation did not significantly effect the participants’ times on attention switching tasks. The contradiction may be due to methodological issues. Anderson and colleagues (2007) used participants that had never received prior mindfulness training and used an 8-week MBSR program to evoke mindfulness. The MBSR program that the participants attended met for 2 hours per week. The participants were encouraged to utilize the techniques they learned in class during the week; however, there was no way of measuring the amount of mindfulness practice the participants utilized on their own. The current study used daily mindfulness training through meditative sitting to ensure participants were involved in daily practice. Allen, Chambers, and Lo (2007) found that attention switching was not enhanced by mindfulness training. The lack of interaction in this study was contradicted by the findings of the present study, but also could be explained by methodological issues. The participants in this particular study completed a 10-day intensive mindfulness course; however, the researchers acknowledged that it was not possible to control or assess the amount of time the participants were actively engaged in the mindfulness exercises. The current study found that scores differed from the control group to the experimental group over time on the DLST, suggesting that mindfulness training did have an effect on attention switching ability. In the current study, the participant’s mean scores in the experimental condition significantly increased from pre-test to post-test on the Working Memory Alphabetical Task. The data suggested that short-term meditative sitting significantly improved the working memory capacity of the participants, although the effects were small. This finding is consistent with the only study that explored the effect of mindful meditation on working memory capacity. Allen, Chambers, and Lo (2007) observed a significant increase in working memory capacity for participants that completed an intensive 10-day mindfulness training course. The DSB test showed significant increases for the experimental group, which was consistent with the current study. The participant’s mean interference scores decreased in the experimental condition between pre-test and post-test for the Stroop Task. The decrease in interference on the Stroop task is consistent with prior research. Chan and Woollacott (2007) found that mindfulness training elicited a significant reduction in interference in the Stroop task. This is consistent with the results of the current study; however, the current study did not produce significant interactions among group and time, whereas Chan and Woollacott (2007) found significant interactions for the type of condition the groups received. There are limitations of the current study worth noting. Meditation is a novel field of study in the psychological community. As such, the knowledge of the complete specific effects of meditation on the brain is not fully known. Therefore, it is difficult to know that the effects were due to meditation or any number of other factors. The level of involvement in the experiment made it difficult to recruit a large number of participants for the experimental condition. Also, the sessions of meditation were contingent upon the participant’s ability to be physically present. The experimental participants were extremely busy; therefore, not every participant was able to formally meditate with the researcher every day. The control participants were busy as well and some of them did not test exactly 18 days apart. It was also impossible for the researcher to know how carefully and intentionally each participant meditated. The instructions may have been interpreted in many different ways. Also, the researcher presided over the testing and meditation sessions, which could have been a potential bias. The results of the current study are largely consistent with prior research in the field of mindful meditation. The results indicated that mindful meditation increased performance on attention switching, sustained attention, cognitive interference, and working memory. Thus, the small cognitive changes elicited by regular short-term mindful meditative practice suggest that mindfulness has positive effects on the executive network of cognition. This effect may be due to the participants’ ability to distance themselves from negative thought patterns. This theory, seen in Hayes and Wilson’s (2003) definition of mindfulness and the practices of mindfulness as a therapy technique, accounts for the increased positive cognitive resources available to the individual participant. Lau and colleagues (2000) and Carmona and colleagues (2004) found that participants using mindfulness as a therapy technique were afforded more cognitive flexibility due to decreased negative obsessive thought patterns. This increased flexibility could have accounted for the increased attention and memory abilities for the participants in the current study; however, there is no way to confirm this theory. The results of the study should be interpreted with caution because of the small nature of the effects. The sample size could have been a crucial issue here. A larger random sample could have generated larger effects, whereas the current study used a small number of college students. It would be interesting for future research to expand the sample size, possibly investigating other aspects of cognitive function. The small effect could also be due to the limited amount of time the participants meditated each day. Allen, Chambers, and Lo (2007) found that performance correlated with the amount of time the participants meditated each day. Future research could expand and limit the amount of time per day for different groups of meditators to further investigate this effect. The results indicate that individuals with no prior meditative experience can experience positive cognitive changes in a relatively short period of time with little training. This novel finding adds the understanding that meditation, albeit a complex state of cognitive awareness, can be utilized by individuals with no prior exposure to Eastern spirituality or thought processes. The nature of the effects on the executive network has marked implications. The executive network is crucial to psychology’s extensive view of intelligence (Braver et al., 2006; Fuster, 2002); therefore, mindful meditation increases specific facets critical to intelligence. This is an exciting application to research involving intelligence. Future research should be aimed at strengthening this relationship, possibly investigating other theories and aspects of intelligence related to mindfulness practices. In summary, the results of the current study concur with the results of prior research on the cognitive effects of mindful meditation. Prior research has shown that mindful meditation increases scores on cognitive tasks testing the executive network of cognition. The current study adds to the understanding of this effect. The current results suggest that short-term mindful meditative practice can elicit small cognitive changes. This is a novel finding because most of the prior research has investigated effects of novice or expert meditators or longer periods of mindfulness training with beginners. The findings of the current study demonstrate that relatively little mindfulness training can have an impact on cognition. These findings are encouraging to the future direction of mindfulness research in psychology. Mindfulness is an effective cognitive intervention technique and shows promise as a benefit in a wide range of psychological research.

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