In the previous post I discussed evidence for the involvement of emotional processes even when performing a purely cognitive task.
A further study investigated which brain areas are involved when a task similar to the Stroop task that was a focus in a previous post, is carried out, while the emotional state of the participant is challenged at the same time. As before, central to the task was the ability to inhibit pre-potent reactions. In each trial a certain number of identical digits, arranged in a 3 x 3 matrix, were presented. This initial display was followed by an affective picture (positive, negative or neutral) and subsequently a second display of digits arranged in a 3 x 3 matrix, again followed by the same affective picture. At the end of each trial the participants had the task to indicate whether there were more digits in the first or in the second display. Interference was introduced by the (irrelevant) identity of the digits. For instance, in a display consisting of, say, five times the digits “3”, the number five would need to be compared to the second digit-display, while the digit itself (here “3”) is irrelevant and should be ignored. The aim of the additional pictures was to serve as distractors and to interfere with task performance.
After six week of meditation practice the behavioural performance improved significantly, in the sense that the participants were less disturbed or affected by the irrelevant negative affective pictures. In the active control group this was not the case. Interestingly, these improvements were accompanied by increased brain activity in the dorsolateral prefrontal cortex, an area of the brain that constitutes an important knot in the executive control network. In addition, the more time participants invested in meditation over these six weeks the stronger was the activation in brain areas implicated in the salience network such as the anterior insula and the cingulate cortex. One is tempted to conclude that these findings indicate the hypothesised progression from improvements of attentional control, indexed by the initial involvement of the executive control network, to improved emotion regulation skills, indexed by the selective involvement of the salience network. This would, indeed be an exciting finding, albeit in competition with previous results (see previous post), which suggest that better emotional acceptance is a prerequisite for improved performance on the Stroop task.
We need to be cautious, though, and consider one important detail of the study. As so often, over the course of the study the meditators engaged in different meditations, in this case a set of four mindfulness practices (from focused breath awareness, to body-scanning, to compassion and to open monitoring) that progressively require more emotional awareness. Presumably, the most dedicated participants will also have engaged more with those emotional awareness practices and would thus exhibit more emotion related changes. Thus, the apparent progression from attention to emotional awareness may be a result of engaging in different types of meditation, rather than of progression in meditation per se. The conclusion that an increase in attentional awareness and meta-cognitive control precedes improved emotional/affective awareness based on these results would thus be a little premature. This consideration highlights again how important it is to study one single form of (mindfulness) meditation practice on its own and for sufficiently long times, if we aim to arrive at a precise and clear understanding of the underlying processes.
We nevertheless gain something interesting from this study: we saw that mindfulness meditation practice can improve metacognitive processes and emotional awareness and that the brain networks we would expect to be involved in this process (in this case the salience network and the executive control network) , indeed appear to be implicated.
My next post will then talk a bit more about these different networks that are likely to play a crucial role even during the briefest sequence of mindfulness meditation.
Allen, M., Dietz, M., Blair, K. S., Van Beek, M., Rees, G., Vestergaard-Poulsen, P., et al. (2012). Cognitive-affective neural plasticity following active-controlled mindfulness intervention. Journal of Neuroscience, 32(44), 15601–15610.
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