How can mindfulness meditation increase our capacity to notice rapidly changing stimuli?

What is it about?

Our ability to perceive sequences of stimuli appearing in close temporal succession is limited. One type of limitation is the “attentional blink”, in which the detection of a target in a rapidly presented sequence of visual stimuli causes a reduction in the detection probability of succeeding targets. A previously published paper (Slagter et al. 2007, PLoS Biology), reported that intensive mindfulness meditation training can reduce the attentional blink, with a corresponding change in an electrical brain signal which is thought to reflect allocation of attentional resources. However, the cognitive mechanisms underlying these changes remain unknown. In this work we develop a simple mathematical model describing how attentional resources vary over time in response to incoming stimuli. According to this model, our attentional capacity is limited by ongoing fluctuations, or “mental noise”, in our minds. When incoming stimuli appear close in time, the net amount of attentional resources they draw is larger than the amount that would have been drawn by each stimuli appearing separately. If, in addition, the underlying mental noise is high, the incoming stimuli can deplete our already strained attentional resources, triggering an “attentional blink”. On the other hand, if the mental noise is low, we are more likely to have enough attentional resources to properly process and perceive the incoming stimuli, even when they appear in rapid succession. Our model suggests that mindfulness meditation reduces the “attentional blink” and changes the corresponding brain signals by modulating mental noise in a particular way: reducing its mean level but increasing its fluctuations. We hypothesize that the mental noise in the model is the same as our introspective notion of mental noise - when it is high, we are distracted and our mind is wandering; when we are calmer and focused the mental noise is low. While it may not come as a surprise (at least not to meditators) that mindfulness meditation can reduce the magnitude of mental noise, the suggestion that it increases fluctuations was unexpected. We speculate that this increased variability in mental fluctuation might reflect a more “diffuse” or “entropic” state of mind which, somewhat paradoxically, seems to be associated with increased attentional capacity in certain circumstances.

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Photo by Medienstürmer on Unsplash

Photo by Medienstürmer on Unsplash

Why is it important?

Our minds are in constant flux, jumping from one thing to another. These mental fluctuations limit our capacity to attend to and notice changes in our environment. Improving our capacity to attend and perceive such changes is obviously of great benefit. For example, it could reduce the likelihood of car accidents which often occur due to the attentional capacity limitations of drivers who must track rapidly changing events in their surroundings. Furthermore, a precise understanding of the mechanisms by which mindfulness meditation influences attentional capacity, could help guide mindfulness based therapeutic interventions for people suffering from attention-deficit/hyperactivity or similar disorders.

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