The cognitive load theory by John Sweller has become the main idea in thinking about education but that doesn’t mean we already know everything. Take this study by Stuyck et al about the “Aha! experience”, which can be summarized as follows:

• The (un)conscious nature of insight was assessed by manipulating cognitive load.
• Under high cognitive load, non-insight solutions required more time than insightful ones.
• As cognitive load increased, non-insight solutions became less frequent.
• Insight solutions remained mostly unaffected by cognitive load.
• Insight solutions appeared not to compete for limited cognitive resources.

Abstract of the study:

The Aha! moment– the sudden insight sometimes reached when solving a vexing problem– entails a different problem-solving experience than solution retrieval reached by an analytical, multistep strategy (i.e., non-insight). To date, the (un)conscious nature of insight remains debated. We addressed this by studying insight under cognitive load. If insight and non-insight problem solving rely on conscious, effortful processes, they should both be influenced by a concurrent cognitive load. However, if unconscious processes characterize insight, cognitive load might not affect it at all. Using a dual-task paradigm, young, healthy adults (N = 106) solved 70 word puzzles under different cognitive loads. We confirmed that insight solutions were more often correct and received higher solution confidence. Importantly, as cognitive load increased, non-insight solutions became less frequent and required more solution time, whereas insightful ones remained mostly unaffected. This implies that insight problem solving did not compete for limited cognitive resources.