Tang et al. · PNAS · 2007

In a randomized study, five days of structured Integrative Body–Mind Training improved measures of executive attention and self-regulation compared with a relaxation control. It suggests attention can be practiced, while not proving that a single visual point creates the same effect.

MacLean et al. · Psychological Science · 2010

A three-month retreat that used sustained selective attention—often on the breath—was associated with better visual discrimination and vigilance than a wait-list comparison. The training was intensive, so it should not be read as evidence for a quick one-minute benefit.

Slagter et al. · PLOS Biology · 2007

After three months of intensive Vipassana practice, participants showed a smaller attentional blink and reduced neural resource allocation to the first target in a rapid visual task. The authors connect this to less capture by competing stimuli.

Mrazek et al. · Psychological Science · 2013

In a randomized two-week course, mindfulness training reduced distracting thoughts and improved working-memory and GRE reading-comprehension measures. The result is about mindfulness training broadly, not about staring at a dot specifically.