Painting as Metacognition
When one starts paying attention to attention, and using that attention to attention intentionally, the practice is called "metacognition" and has been shown to amplify learning. Painting is an attentional practice that, when done with awareness of this aspect of painting, is a metacognitive exercise.
To be exact, painting forces a continuous awareness, free of mind-wandering, to where the brush is at each present moment. At the same time, as one's painting practice deepens, the brush-awareness becomes finer: the pressure of the brush, the amount of paint on the brush at each moment, the position of the fingers, the way rotating the brush changes the line, the relationship between the figure the brush is painting and the ground that emerges from the negative space between brush strokes. For very fine and precise work, it is necessary to simultaneously coordinate the movements of hands, fingers, and eyes with the movement of the breath - painting smoothly on the outbreath for the finest lines. And attention to the breath appears to play a role in modulating consciousness.
Fifty years ago, I took a Chinese brush-painting from Charlie Leong, who had taught Gary Snyder in the 1950s. My first sessions consisted of loading the brush with water and painting on stacks of newspaper. Then I spent time learning to make ink from an inkstick and water. In brush-painting, the painter spends more time and puts more conscious thought into making the ink and loading the brush than in the brush strokes, which are supposed to be spontaneous and dance-like. In recent years, painting with acrylics, when thinning tube pigment to the right consistency by mixing it with water, I've been practicing putting as much awareness into the mixing and the loading of the brush as I put into the painting -- which is slower, more deliberate, constrained, and exacting than brush painting.