Archive for February 2009
We engage in numerous discussions throughout the day, about a variety of topics, from work assignments to the Super Bowl to what we are having for dinner that evening. We effortlessly move from conversation to conversation, probably not thinking twice about our brain’s ability to understand everything that is being said to us. How does the brain turn seemingly random sounds and letters into sentences with clear meaning?
In a new report in Current Directions in Psychological Science, a journal of the Association for Psychological Science, psychologist Jos J.A. Van Berkum from the Max Planck Institute in The Netherlands describes recent experiments using brain waves to understand how we are able to make sense of sentences.
In these experiments, Van Berkum and his colleagues examined Event Related Potentials (or ERPs) as people read or heard critical sentences as part of a longer text, or placed in some other type of context. ERPs are changes in brain activity that occur when we hear a certain stimulus, such as a tone or a word. Due to their speed, ERPs are useful for detecting the incredibly fast processes involved in understanding language.
Analysis of the ERPs has consistently indicated just how quickly the brain is able to relate unfolding sentences to earlier ones. For example, Van Berkum and colleagues have shown that listeners only need a fraction of a second to determine that a word is out of place, given what the wider story is about. As soon as listeners hear an unexpected word, their brain generates a specific ERP, the N400 effect (so named because it is a negative deflection peaking around 400 milliseconds). And even more interesting, this ERP will usually occur before the word is even finished being spoken.
In addition to the words themselves, the person speaking them is a crucial component in understanding what is being said. Van Berkum also saw an N400 effect occurring very rapidly when the content of a statement being spoken did not match with the voice of the speaker (e.g. “I have a large tattoo on my back” in an upper-class accent or “I like olives” in a young child’s voice). These findings suggest that the brain very quickly classifies someone based on what their voice sounds like and also makes use of social stereotypes to interpret the meaning of what is being said. Van Berkum speculates that “the linguistic brain seems much more ‘messy’ and opportunistic than originally believed, taking any partial cue that seems to bear on interpretation into account as soon as it can.”
But how does the language brain act so fast? Recent findings suggest that, as we read or have a conversation, our brains are continuously trying to predict upcoming information. Van Berkum suggests that this anticipation is a combination of a detailed analysis about what has been said before with taking ‘quick-and-dirty’ shortcuts to figure out what, most likely, the next bit of information will be.
One important element in keeping up with a conversation is knowing what or whom speakers are actually referring to. For example, when we hear the statement, “David praised Linda because. . .,” we expect to find out more about Linda, not David. Van Berkum and colleagues showed that when listeners heard “David praised Linda because he. . .,” there was a very strong ERP effect occurring with the word “he,” of the type that is also elicited by grammatical errors. Although the pronoun is grammatically correct in this statement, the ERP occurred because the brain was just not expecting it. This suggests that the brain will sometimes ignore the rules of grammar when trying to comprehend sentences.
These findings reveal that, as we make sense of an unfolding sentence, our brains very rapidly draw upon a wide range of information, including what was stated previously and who the speaker is, in helping us understand what is being said to us. Sentence understanding is not just about diligently combining stored word meanings. The brain rapidly throws in everything it knows, and it is always looking ahead.
Current Directions in Psychological Science, 2008; 17 (6): 376 DOI: 10.1111/j.1467-8721.2008.00609.x
Understanding Sentences in Context: What Brain Waves Can Tell Us.
Jos J.A. Van Berkum
ABSTRACT—Language comprehension looks pretty easy. You pick up a novel and simply enjoy the plot, or ponder the human condition. You strike a conversation and listen to whatever the other person has to say. Although what you’re taking in is a bunch of letters and sounds, what you really perceive—if all goes well—is meaning. But how do you get from one to the other so easily? The experiments with brain waves (event-related brain potentials or ERPs) reviewed here show that the linguistic brain rapidly draws upon a wide variety of information sources, including prior text and inferences about the speaker. Furthermore, people anticipate what might be said about whom, they use heuristics to arrive at the earliest possible interpretation, and if it makes sense, they sometimes even ignore the grammar. Language comprehension is opportunistic, proactive, and, above all, immediately context-dependent.
Self-control is one of our most cherished values. We applaud those with the discipline to regulate their appetites and actions, and we try hard to instill this virtue in our children. We celebrate the power of the mind to make hard choices and keep us on course. But is it possible that willpower can sometimes be an obstacle rather than a means to happiness and harmony?
Tufts University psychologists Evan Apfelbaum and Samuel Sommers were intrigued by the notion that too much self-control may indeed have a downside – and that relinquishing some power might be paradoxically tonic, both for individuals and for society.
They explored the virtue of powerlessness in the arena of race relations. They figured that well-intentioned people are careful – sometimes hyper-careful – not to say the wrong thing about race in a mixed-race group. Furthermore, they thought that such effortful self-control might actually cause both unease and guarded behavior, which could in turn be misconstrued as racial prejudice.
To test this, they ran a group of white volunteers through a series of computer-based mental exercises that are so challenging that they temporarily deplete the cognitive reserves needed for discipline. Once they had the volunteers in this compromised state of mind, they put them (and others not so depleted) into a social situation with the potential for racial tension – they met with either a white or black interviewer and discussed racial diversity. Afterward, the volunteers rated the interaction for comfort, awkwardness, and enjoyment. In addition, independent judges – both black and white – analyzed the five-minute interactions, commenting on how cautious the volunteers were, how direct in their answers – and how racially prejudiced.
As reported in Psychological Science, a journal of the Association for Psychological Science, those who were mentally depleted – that is, those lacking discipline and self-control – found talking about race with a black interviewer much more enjoyable than did those with their self-control intact. That’s presumably because they weren’t working so hard at monitoring and curbing what they said. What’s more, independent black observers found that the powerless volunteers were much more direct and authentic in conversation. And perhaps most striking, blacks saw the less inhibited whites as less prejudiced against blacks. In other words, relinquishing power over oneself appears to thwart over-thinking and “liberate” people for more authentic relationships.
Psychological Science Volume 20, Issue 2, Date: February 2009, Pages: 139-143
Liberating Effects of Losing Executive Control
Evan P. Apfelbaum, Samuel R. Sommers
ABSTRACT—Across numerous domains, research has consistently linked decreased capacity for executive control to negative outcomes. Under some conditions, however, this deficit may translate into gains: When individuals’ regulatory strategies are maladaptive, depletion of the resource fueling such strategies may facilitate positive outcomes, both intra- and interpersonally. We tested this prediction in the context of contentious intergroup interaction, a domain characterized by regulatory practices of questionable utility. White participants discussed approaches to campus diversity with a White or Black partner immediately after performing a depleting or control computer task. In intergroup encounters, depleted participants enjoyed the interaction more, exhibited less inhibited behavior, and seemed less prejudiced to Black observers than did control participants—converging evidence of beneficial effects. Although executive capacity typically sustains optimal functioning, these results indicate that, in some cases, it also can obstruct positive outcomes, not to mention the potential for open dialogue regarding divisive social issues.
Scientists have long known that interrupting the 24-hour circadian rhythm plays havoc with the lives and health of medical, military and airline personnel, factory employees and travelers.
A new paper by University of Notre Dame biologist Giles Duffield and a team of researchers that appears in this month’s edition of the journal Cell Biology sheds new light on circadian timing systems and focuses on a key gene that seems to regulate the response of the circadian clock to light signals.
“Circadian rhythms are important and exciting because they pervade many aspects of biochemistry, physiology and behavior, either subtly or overtly,” Duffield said. “For example, the human sleep-wake cycle is a very obvious rhythm and tightly gated to the night, while perhaps less obvious is that virtually all hormones oscillate with a 24-hour rhythm and up to 10 percent of genes in each cell are rhythmically controlled.” An estimated 16 percent of the U.S. working population is involved in rotational shift work, and a significant population is affected by jet lag and related sleep-wake disorders. The impact of the large shifts in the body’s internal clock that these individuals experience can be profound, contributing to increased accident rates, medical errors and the development of particular illnesses.
“Both the Three Mile Island disaster in 1979 and the Chernobyl disaster in 1986 occurred late at night or early in the morning,” Duffield said. “Most truck accidents occur around 2 a.m. Incidents of cancer and cardiovascular disease are elevated in trans-Atlantic airline staff and in shift workers.”
The master circadian clock in the human resides within the suprachiasmatic nucleus of the hypothalamic brain and receives direct input from the retina (eye) through which the clock can be reset or synchronized on a daily basis to the prevailing light-dark cycle. This provides both time of day and also time of year information to the brain and body. Things can go wrong with the internal clocks when either the clock system or its light input pathway is disrupted.
Using DNA microarray techniques, Duffield and the other researchers identified an important gene called the “Inhibitor of DNA-binding 2” (Id2) and found that the gene is rhythmically expressed in various tissues including the suprachiasmatic nucleus.
“In the last few years, my laboratory has focused on a family of transcription factor genes expressed in the suprachiasmatic nucleus, liver and heart,” Duffield said. “In conjunction with colleagues at Dartmouth Medical School and Norris Cotton Cancer Center, we produced a knockout mouse that does not express the Id2 gene and is thus null for the functional Id2 protein. By exposing these mice to a time-zone change in their light-dark cycle, we were able to examine the effect of artificial jet lag. We altered the light-dark conditions for these mice to produce an effect that was the equivalent of a person flying from Athens to Los Angeles, a 10-hour delay of their cycle.
“We discovered that the knockout mice took only one or two days to recover from jet lag, while unaltered mice required four or five days to fully adjust. It’s like we removed the hand brake on their molecular machinery.”
The experimental results have important implications for understanding the development and functioning of the circadian clock in the brain and peripheral tissues such as the liver and heart.
“Eight years ago, researchers realized that even if you destroy the suprachiasmatic nuclei of the hypothalamus or examine peripheral organs in isolation, there are still working clock systems in many other tissues of the body,” Duffield said.
It turns out that many of the cells throughout our bodies have an intrinsic circadian clock mechanism and that jet lag and shift work can produce internal asynchrony between each of our tissue-specific clocks.
Our brains, on a daily basis, generate the hormonal and neuronal signals that influence the cellular clocks in the peripheral tissues. If this communication line is disrupted, the liver, for example, ends up on one time zone, and the brain on another.
These peripheral clocks in the body’s organ systems cannot themselves receive information directly. To know what time of day it is in relation to the external environment, these tissues depend on signals originating in the suprachiasmatic nucleus: every day the brain sends signals that inform the peripheral cells to adjust the phase of their rhythms, like the pin of a wrist watch being moved a little bit forward or backward.
If we could somehow tinker with this system in the adult human, it might be possible to reduce the effects of jet-lag and shift work by rapidly adjusting our internal clock. Duffield and the team of researchers may have uncovered an important target for such remedies by identifying the Id2 gene, which appears to in some way regulate the magnitude of response of the circadian clock to light signals.
Curr Biol. 2009 Feb 11. [Epub ahead of print]
A Role for Id2 in Regulating Photic Entrainment of the Mammalian Circadian System.
Duffield GE, Watson NP, Mantani A, Peirson SN, Robles-Murguia M, Loros JJ, Israel MA, Dunlap JC.
Inhibitor of DNA binding genes (Id1-Id4) encode helix-loop-helix (HLH) transcriptional repressors associated with development and tumorigenesis [1, 2], but little is known concerning the function(s) of these genes in normal adult animals. Id2 was identified in DNA microarray screens for rhythmically expressed genes [3-5], and further analysis revealed a circadian pattern of expression of all four Id genes in multiple tissues including the suprachiasmatic nucleus. To explore an in vivo function, we generated and characterized deletion mutations of Id2 and of Id4. Id2(-/-) mice exhibit abnormally rapid entrainment and an increase in the magnitude of the phase shift of the pacemaker. A significant proportion of mice also exhibit disrupted rhythms when maintained under constant darkness. Conversely, Id4(-/-) mice did not exhibit a noticeable circadian phenotype. In vitro studies using an mPer1 and an AVP promoter reporter revealed the potential for ID1, ID2, and ID3 proteins to interact with the canonical basic HLH clock proteins BMAL1 and CLOCK. These data suggest that the Id genes may be important for entrainment and operation of the mammalian circadian system, potentially acting through BMAL1 and CLOCK targets.
While science tries to understand the stuff dreams are made of, humans, from cultures all over the world, continue to believe that dreams contain important hidden truths, according to newly published research.
In six different studies, researchers surveyed nearly 1,100 people about their dreams. “Psychologists’ interpretations of the meaning of dreams vary widely,” said Carey Morewedge, an assistant professor at Carnegie Mellon University and the study’s lead author. “But our research shows that people believe their dreams provide meaningful insight into themselves and their world.”
In one study that surveyed general beliefs about dreams, Morewedge and co-author Michael Norton, an assistant professor at Harvard Business School, surveyed 149 university students in the United States, India and South Korea. The researchers asked the students to rate different theories about dreams. Across all three cultures, an overwhelming majority of the students endorsed the theory that dreams reveal hidden truths about themselves and the world, a belief also endorsed by a nationally representative sample of Americans.
In another study reported in the article, the researchers wanted to explore how dreams might influence people’s waking behavior. They surveyed 182 commuters at a Boston train station, asking them to imagine that one of four possible scenarios had happened the night before a scheduled airline trip: The national threat level was raised to orange, indicating a high risk of terrorist attack; they consciously thought about their plane crashing; they dreamed about a plane crash; or a real plane crash occurred on the route they planned to take. A dream of a plane crash was more likely to affect travel plans than either thinking about a crash or a government warning, and the dream of a plane crash produced a similar level of anxiety as did an actual crash.
Finally, the researchers wanted to find out whether people perceive all dreams as equally meaningful, or whether their interpretations were influenced by their waking beliefs and desires. In another study, 270 men and women from across the United States took a short online survey in which they were asked to remember a dream they had had about a person they knew. People ascribed more importance to pleasant dreams about a person they liked as compared to a person they did not like, while they were more likely to consider an unpleasant dream more meaningful if it was about a person they disliked.
“In other words,” said Morewedge, “people attribute meaning to dreams when it corresponds with their pre-existing beliefs and desires. This was also the case in another experiment which demonstrated that people who believe in God were likely to consider any dream in which God spoke to them to be meaningful; agnostics, however, considered dreams in which God spoke to be more meaningful when God commanded them to take a pleasant vacation than when God commanded them to engage in self-sacrifice.”
The authors say more research is needed to explore fully how people interpret their dreams, and in what cases dreams may actually reveal hidden information.. “Most people understand that dreams are unlikely to predict the future but that doesn’t prevent them from finding meaning in their dreams, whether their contents are mundane or bizarre,” said Morewedge.
Journal of Personality and Social Psychology. Vol 96(2), Feb 2009, 249-264. DOI: 10.1037/a0013264
When dreaming is believing: The (motivated) interpretation of dreams.
This research investigated laypeople’s interpretation of their dreams. Participants from both Eastern and Western cultures believed that dreams contain hidden truths (Study 1) and considered dreams to provide more meaningful information about the world than similar waking thoughts (Studies 2 and 3). The meaningfulness attributed to specific dreams, however, was moderated by the extent to which the content of those dreams accorded with participants’ preexisting beliefs–from the theories they endorsed to attitudes toward acquaintances, relationships with friends, and faith in God (Studies 3-6). Finally, dream content influenced judgment: Participants reported greater affection for a friend after considering a dream in which a friend protected rather than betrayed them (Study 5) and were equally reluctant to fly after dreaming or learning of a plane crash (Studies 2 and 3). Together, these results suggest that people engage in motivated interpretation of their dreams and that these interpretations impact their everyday lives. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
The underlying sense of being in control of our own actions is challenged by new research from UCL (University College London) which demonstrates that the choices we make internally are weak and easily overridden compared to when we are told which choice to make.
The research is one of the first neuroscientific studies to look at changing one’s mind in situations where the initial decision was one’s own ‘free choice’. Free choices can be defined as actions occurring when external cues are largely absent – for example, deciding which dish to choose from a restaurant menu.
The researchers asked study participants to choose which of two buttons they would press in response to a subsequent signal, while their brain activity was recorded using EEG (electroencephalogram). Some choices were made freely by the volunteers and other choices were instructed by arrows on a screen in front of them. The volunteers’ choices were occasionally interrupted by a symbol asking them to change their mind, after they had made their choice, but before they had actually pressed the button.
First author Stephen Fleming, UCL Institute of Neurology, said: “When people had chosen for themselves which action to make, we found that the brain activity involved in changing one’s mind, or reprogramming these ‘free’ choices was weak, relative to reprogramming of choices that were dictated by an external stimulus. This suggests that the brain is very flexible when changing a free choice – rather like a spinning coin, a small nudge can push it one way or the other very easily.
“The implication is that, despite our feelings of being in control, our own internal choices are flexible compared to those driven by external stimuli, such as a braking in response to a traffic light. This flexibility might be important – in a dynamic world, we need to be able to change our plans when necessary.”
Professor Patrick Haggard, UCL Institute of Cognitive Neuroscience, added: “Our study has two implications for our understanding of human volition. First, our brains contain a mechanism to go back and change our mind about our choices, after a choice is made but before the action itself. Our internal decisions are not set in stone, but can be re-evaluated right up to the last moment. Second, changing an internal choice in this way seems to be easier than changing a choice guided by external instructions.
“We often think about our own internal decisions as having the strength of conviction, but our results suggest that the brain is smart enough to make us flexible about what we want. The ability to flexibly adjust our decisions about what we do in the current situation is a major component of intelligence, and has a clear survival value.”
Cerebral Cortex, Feb 11, 2009 DOI: 10.1093/cercor/bhn252
When the Brain Changes its Mind: Flexibility of Action Selection in Instructed and Free Choices.
Stephen M. Fleming, Rogier B. Mars, Thomas E. Gladwin and Patrick Haggard
The neural mechanisms underlying the selection and initiation of voluntary actions in the absence of external instructions are poorly understood. These mechanisms are usually investigated using a paradigm where different movement choices are self-generated by a participant on each trial. These “free choices” are compared with “instructed choices,” in which a stimulus informs subjects which action to make on each trial. Here, we introduce a novel paradigm to investigate these modes of action selection, by measuring brain processes evoked by an instruction to either reverse or maintain free and instructed choices in the period before a “go” signal. An unpredictable instruction to change a response plan had different effects on free and instructed choices. In instructed trials, change cues evoked a larger P300 than no-change cues, leading to a significant interaction of choice and change condition. Free-choice trials displayed a trend toward the opposite pattern. These results suggest a difference between updating of free and instructed action choices. We propose a theoretical framework for internally generated action in which representations of alternative actions remain available until a late stage in motor preparation. This framework emphasizes the high modifiability of voluntary action.
Why do people gamble if they know that the house always wins? Researchers at the University of Cambridge argue that near-misses, where the gambler narrowly misses out on the jackpot, may provide part of the answer.
Although the gambler loses their bet on a near-miss, where the slot machine reel stops one position from the ‘payline’, the researchers found that near-miss outcomes make people want to carry on gambling and caused brain activity in areas that normally process winning money.
The study, published in the journal Neuron, scanned the brains of 15 people while they gambled on a computerised slot machine that delivered occasional 50p wins. These wins caused responses in brain areas that are known to process natural rewards like chocolate, and also drugs linked with abuse. The researchers showed that near-misses (for example, two cherries and an orange but the not the three cherries necessary for a win) also elicited activity in this brain reward system.
In a second experiment performed outside the scanner, volunteers rated the near-miss events as unpleasant but simultaneously rated their desire to continue the game as higher after a near-miss. Previous research has shown that gamblers play slot machines with near-misses for longer than machines rigged with no near-misses.
The research, which was funded by the Economic and Social Research Council and the Responsibility in Gambling Trust, found brain activity to near-misses in the striatum and insula cortex of the brain. These areas are thought to be involved in drug addiction, and receive input from the brain chemical dopamine (a neurotransmitter which plays a role in ‘reward’).
Gambling is a widespread form of entertainment in Britain, but some individuals become problem (or ‘compulsive’) gamblers who lose control over their gambling. The symptoms of problem gambling (e.g. cravings, and betting larger sums of money over time) are similar to the symptoms of drug addiction, but it is not well understood exactly how behaviours (like gambling) can become addictive.
This new research found that volunteers who showed a greater response to near-misses in the insula also tended to score higher on a questionnaire containing statements that are endorsed by problem gamblers (e.g. “Losses when gambling are bound to be followed by a series of wins.”). The authors suggest that the functioning of the insula region may change as gambling becomes addictive.
Dr Luke Clark, lead author of the study, said: “Gamblers often interpret near-misses as special events, which encourage them to continue to gamble. Our findings show that the brain responds to near-misses as if a win has been delivered, even though the result is technically a loss.
“On games where there is some skill involved, like target practice, it makes sense to pay attention to near-misses. However, on gambling games where the wins are random, like slot machines or roulette, near-misses do not signal your future success. Importantly, our volunteers in this study were not regular or problem gamblers, and so these findings suggest that the brain may naturally respond to near-misses in this way.”
Neuron, Volume 61, Issue 3, 481-490, 12 February 2009
Gambling Near-Misses Enhance Motivation to Gamble and Recruit Win-Related Brain Circuitry
Luke Clark, Andrew J. Lawrence, Frances Astley-Jones andNicola Gray
Near-miss events, where unsuccessful outcomes are proximal to the jackpot, increase gambling propensity and may be associated with the addictiveness of gambling, but little is known about the neurocognitive mechanisms that underlie their potency. Using a simplified slot machine task, we measured behavioral and neural responses to gambling outcomes. Compared to full-misses, near-misses were experienced as less pleasant, but increased desire to play. This effect was restricted to trials where the subject had personal control over arranging their gamble. Near-miss outcomes recruited striatal and insula circuitry that also responded to monetary wins; in addition, near-miss-related activity in the rostral anterior cingulate cortex varied as a function of personal control. Insula activity to near-misses correlated with self-report ratings as well as a questionnaire measure of gambling propensity. These data indicate that near-misses invigorate gambling through the anomalous recruitment of reward circuitry, despite the objective lack of monetary reinforcement on these trials.
Zen meditation – a centuries-old practice that can provide mental, physical and emotional balance – may reduce pain according to Université de Montréal researchers. A new study in the January edition of Psychosomatic Medicine reports that Zen meditators have lower pain sensitivity both in and out of a meditative state compared to non-meditators.
Joshua A. Grant, a doctoral student in the Department of Physiology, co-authored the paper with Pierre Rainville, a professor and researcher at the Université de Montréal and it’s affiliated Institut universitaire de gériatrie de Montréal. The main goal of their study was to examine whether trained meditators perceived pain differently than non-meditators.
“While previous studies have shown that teaching chronic pain patients to meditate is beneficial, very few studies have looked at pain processing in healthy, highly trained meditators. This study was a first step in determining how or why meditation might influence pain perception.” says Grant.
Meditate away the pain
For this study, the scientists recruited 13 Zen meditators with a minimum of 1,000 hours of practice to undergo a pain test and contrasted their reaction with 13 non-meditators. Subjects included 10 women and 16 men between the ages of 22 to 56.
The administered pain test was simple: A thermal heat source, a computer controlled heating plate, was pressed against the calves of subjects intermittently at varying temperatures. Heat levels began at 43 degrees Celsius and went to a maximum of 53 degrees Celsius depending on each participant’s sensitivity. While quite a few of the meditators tolerated the maximum temperature, all control subjects were well below 53 degrees Celsius.
Grant and Rainville noticed a marked difference in how their two test groups reacted to pain testing – Zen meditators had much lower pain sensitivity (even without meditating) compared to non-meditators. During the meditation-like conditions it appeared meditators further reduced their pain partly through slower breathing: 12 breaths per minute versus an average of 15 breaths for non-meditators.
“Slower breathing certainly coincided with reduced pain and may influence pain by keeping the body in a relaxed state.” says Grant. “While previous studies have found that the emotional aspects of pain are influenced by meditation, we found that the sensation itself, as well as the emotional response, is different in meditators.”
The ultimate result? Zen meditators experienced an 18 percent reduction in pain intensity. “If meditation can change the way someone feels pain, thereby reducing the amount of pain medication required for an ailment, that would be clearly beneficial,” says Grant.
Psychosomatic Medicine 71:106-114 (2009
Pain Sensitivity and Analgesic Effects of Mindful States in Zen Meditators: A Cross-Sectional Study
Joshua A. Grant, BSc and Pierre Rainville, PhD
Objective: To investigate pain perception and the potential analgesic effects of mindful states in experienced Zen meditators.
Methods: Highly trained Zen meditators (n = 13; >1000 hours of practice) and age/gender-matched control volunteers (n = 13) received individually adjusted thermal stimuli to elicit moderate pain on the calf. Conditions included: a) baseline-1: no task; b) concentration: attend exclusively to the calf; c) mindfulness: attend to the calf and observe, moment to moment, in a nonjudgmental manner; and d) baseline-2: no task.
Results: Meditators required significantly higher temperatures to elicit moderate pain (meditators: 49.9°C; controls: 48.2°C; p = .01). While attending “mindfully,” meditators reported decreases in pain intensity whereas control subjects showed no change from baseline. The concentration condition resulted in increased pain intensity for controls but not for meditators. Changes in pain unpleasantness generally paralleled those found in pain intensity. In meditators, pain modulation correlated with slowing of the respiratory rate and with greater meditation experience. Covariance analyses indicated that mindfulness-related changes could be partially explained by changes in respiratory rates. Finally, the meditators reported higher tendencies to observe and be nonreactive of their own experience as measured on the Five Factor Mindfulness Questionnaire; these factors correlated with individual differences in respiration.
Conclusions: These results indicated that Zen meditators have lower pain sensitivity and experience analgesic effects during mindful states. Results may reflect cognitive/self-regulatory skills related to the concept of mindfulness and/or altered respiratory patterns. Prospective studies investigating the effects of meditative training and respiration on pain regulation are warranted.