We conducted three experiments to investigate the effects of how experiences for solving a source task subconsciously affect problem solving for a target insight problem. In Experiment 1, we verified an experimental paradigm developed for this investigation. We found that the experiences solving the source task actually improved the target problem solving even though the participants were not aware the correspondence between the two tasks. Experiment 2 revealed that the effect that the source task improved problem solving for the target task was not brought about by the perceptual feature shared by the two tasks, but by eye tracking experiences while solving the source task, relaxing the constraint that prevents the solution for the target task. Experiment 3 suggested that the effect emerged for relaxing the constraint only; did not for shifting search for an adequate problem space that involves the target solution. We concluded that in insight problem solving people can use analogical cues without awareness to relax fixations rather than to shift search for the problem spaces.