Interesting. This sounds like its related to triggering "system 2" as Kahneman would call it in "Thinking, Fast and Slow"
Experimenters recruited 40 Princeton students to take the
CRT [Shane Frederick's Cognitive Reflection Test]. Half
of them saw the puzzles in a small font in washed-out
gray print. The puzzles were legible, but the font
induced cognitive strain. The results tell a clear story:
90% of the students who saw the CRT in normal font made
at least one mistake in the test, but the proportion
dropped to 35% when the font was barely legible. You read
this correctly: performance was better with the bad font.
Cognitive strain, whatever its source, mobilizes System 2
[slow, conscious, laborious thinking], which is more
likely to reject the intuitive answer suggested by System
1 [the immediate, unreflective thinking by which we make
most of our minute-to-minute judgments].[1]