The paper investigated "implicit sequence learning tasks in which optimal learning may in fact be impeded by the engagement of effortful control processes." (fr

The paper investigated "implicit sequence learning tasks in which optimal learning may in fact be impeded by the engagement of effortful control processes." (from the abstract) "Optimal learning" in the context of implicit learning is evidently desirable, and by extension, mindfulness-induced impairment of implicit learning is undesirable. I am not an expert in this topic, but if I had to distill my understanding of the paper into a sentence of plain English I would say: There is a type of learning which is not achieved through deliberate effort but rather occurs naturally with repeated experience, and this learning can actually be impaired by focusing too hard on the information presented. The task they tested seems to be a pattern recognition task, as described in this paper: http://www.jneurosci.org/content/27/38/10073.full http://www.jneurosci.org/content/27/38/10073.full.