This study of the benefits of mindfulness practice in reducing cognitive rigidity came out a while ago, back in May, but I am not sure how much coverage it received. This study attempts to examine our tendency toward cognitive‘‘blinding’’ to novel solutions, which they define as a form of cognitive rigidity. They define cognitive rigidity as "a resistance to change in beliefs, attitudes or personal habits, or the tendency to develop and perseverate in the use of mental or behavioral sets."
The study proposes that mindfulness practice reduces this rigidity. This topic is highly relevant to the series of posts I have been working on of late - Global Workspace Theory and the Future Evolution of Consciousness. Increasing cognitive flexibility allows for greater access to normally unconscious brain networks, which then makes possible new expansions in consciousness.
AbstractTwo experiments examined the relation between mindfulness practice and cognitive rigidity by using a variation of the Einstellung water jar task. Participants were required to use three hypothetical jars to obtain a specific amount of water. Initial problems were solvable by the same complex formula, but in later problems (“critical” or “trap” problems) solving was possible by an additional much simpler formula. A rigidity score was compiled through perseverance of the complex formula. In Experiment 1, experienced mindfulness meditators received significantly lower rigidity scores than non-meditators who had registered for their first meditation retreat. Similar results were obtained in randomized controlled Experiment 2 comparing non-meditators who underwent an eight meeting mindfulness program with a waiting list group. The authors conclude that mindfulness meditation reduces cognitive rigidity via the tendency to be “blinded” by experience. Results are discussed in light of the benefits of mindfulness practice regarding a reduced tendency to overlook novel and adaptive ways of responding due to past experience, both in and out of the clinical setting.
Citation: Greenberg J, Reiner K, Meiran N (2012) “Mind the Trap”: Mindfulness Practice Reduces Cognitive Rigidity. PLoS ONE 7(5): e36206. doi:10.1371/journal.pone.0036206
Here is the introduction to the paper, which sets up the issue they are examining and the history of the science related to it - including their working definition of mindfulness.
IntroductionExperience may blind us from recognizing obvious solutions to problems. Research shows that physicians and health care professionals are likely to overlook the correct diagnosis in cases which do not match their experience . Similar findings have been reported concerning difficulties in reframing clinical situations as experienced by healthcare professionals [2,3], and difficulties of managers and decision makers in replacing existing procedures with new, improved and simpler ones . This ‘‘blinding’’ to novel solutions may be considered a form of cognitive rigidity, which has commonly been defined as a resistance to change in beliefs, attitudes or personal habits , or the tendency to develop and perseverate in the use of mental or behavioral sets .
Such cognitive rigidity may play a key role in psychopathlogy (for reviews see [6,7], see also ). It has been closely linked to the inability of suicidal individuals to consider alternatives that may be accessible to another person [9,10], as well as to rumination, a major risk factor of depression . Similar forms of cognitive rigidity were also indicated in obsessions [12,13], alcohol dependence
, eating disorders , and Attention Deficit Disorder [16–20]. In this paper, we propose that mindfulness meditation may provide a means of decreasing the aforementioned type of cognitive rigidity.
Mindfulness is a term which has developed from early eastern traditions and has been commonly defined as "paying attention in a particular way: on purpose, in the present moment and nonjudgmentally’’ . Although some have directly linked mindfulness to a practice of meditation (e.g. [22–24]), others (e.g. [25–27]) have referred to it as rather independent from meditation practice. Mindfulness has additionally been described as a theoretical construct, a psychological process , and a trait (see [29,30] for a recent discussion of discrepancies between various definitions of mindfulness). Nevertheless, mindfulness has been commonly claimed to involve regulation of the focus of attention towards the current experience, a willingness to come in contact with and be receptive to experience rather than avoid it or cope by means of repression, and to involve adopting a ‘‘beginners mind’’ and seeing things in a ‘‘fresh’’ way . These last attributes of mindfulness in particular seem to potentially immune one from being blinded by experience.
Mindfulness has received a great deal of empirical attention over the last three decades, and various psychotherapeutic techniques based on mindfulness have been developed (e.g. [22,32,33]). Mindfulness based interventions have been shown to alleviate symptoms of a variety of clinical conditions such as suicidal ideation and manic symptoms , relapse reduction in recurrent major depression (see [35–37] for recent reviews), rumination ([38,39] see  for differential effects of mindfulness on adaptive and maladaptive rumination), addictions and substance use disorders [41,42], eating disorders (see  for a review), generalized anxiety , obsessive compulsive disorder (OCD) , and attention deficit/hyperactivity disorder (ADHD) . Interestingly, many of the disorders which benefit from mindfulness mediation are also characterized by some form of rigidity, suggesting that the efficacy of mindfulness may perhaps be mediated by reduced rigidity.
In addition to studying mindfulness as a form of therapeutic intervention, there has been a growing body of research over the last years examining various cognitive abilities related to mindfulness, most of which focusing on various measures of attention and memory (see  for a review). Only few studies have directly addressed the relation between mindfulness and cognitive flexibility or rigidity. Although some studies did not find differences between meditators and non-meditators in rigidity related tasks (e.g [47,48]), others have found that meditators exhibit decreased Stroop interference [49,50](in a Zen meditation sample). The Stroop task requires participants to name the ink color in which color words are written. The interference reflects automaticity with regards to the fact that participants cannot avoid reading the words. This inability to flexibly adapt to novel and non-habitual task requirements may be taken as evidence for inflexibility. Along the same line, other studies found that meditators exhibit superior visual perspective switching on a multiple perspective images task , exhibit superior verbal fluency [52,53], and perform better than controls on a category production task  and the Hayling task, requiring participants to complete sentences with unrelated and nonsensical words . Mindfulness meditators have also been shown to exhibit reduced rumination compared to controls [38–40], which may also be related to reduced rigidity as reflected in the adoption of repetitive thought patterns concerning distressing symptoms, their causes and implications .
Importantly, none of the aforementioned tasks tap the tendency to be ‘‘blinded’’ by experience, and overlook simple, obvious novel solutions to a given problem, which is what we studied in this work. To this end, we adopted the water jar paradigm developed by Luchins . We had chosen this task over other measures of rigidity since it directly captures the notion of missing obvious adaptive solutions that lie right ‘‘under the nose’’ due to being caught up in learned and repetitive thought patterns. Furthermore, this particular form of rigidity seems most relevant to mindfulness meditation, which is said to involve relating to the present situation with decreased reliance on former knowledge and experience . The water jar paradigm was designed to measure the Einstulling effect, a term used to describe rigid thought patterns formed through experience which prevents identifying more adaptive approaches and solutions. In this task, participants are required to use three hypothetical jars to obtain a specific amount of water. Initial problems are solvable by the same complex formula, but in later ‘‘critical’’ problems a much simpler formula is also appropriate. In these trials, experience is said to comprise a ‘‘trap’’ which may result in overlooking the simple formula. A rigidity score is compiled, reflecting the degree of perseverative use of the complex formula. Since mindfulness is said to be characterized by focusing on the present moment with a ‘‘beginners’ mind’’, we hypothesize that mindfulness experience would result in lower rigidity scores. This hypothesis was examined in two studies. Experiment 1 compared a sample of experienced mindfulness meditators with a comparison group of people who had taken an active interest in mindfulness and had registered to a mindfulness retreat, yet at the time of assessment did not have any formal meditation experience. We chose this group in an attempt to match meditators inclinations and personality characteristics. In Experiment 2, we compared two, randomly assigned groups of non-meditators: a group who underwent eight sessions of structured mindfulness training and a waiting list group, before and after mindfulness training of the mindfulness group.