Figure 4. External reward incentive does not affect intrinsic motivation but enhances accuracy, particularly following incorrect responses.

Participants in the “Reward” group were instructed that they would receive a monetary bonus based on final task performance. “Intrinsic” participants are those who spent at least half of the free-choice time on remote associates problems. This allowed us to identify four distinct subgroups who were: (i) low in intrinsic motivation and not offered reward (“No Motivation,” red bar), (ii) low in intrinsic motivation and offered an external reward for performance (“Reward Only,” yellow bar), (iii) intrinsically motivated without additional reward (“Intrinsic Only,” blue bar), or (iv) both intrinsically motivated and offered the additional reward for performance (“Intrinsic & Reward,” green bar). (a) External reward incentive did not impact the amount of free-choice time that participants allocated to completing puzzles during the free-choice period (F(1, 21) = 0.0930, p = 0.48 and F(1, 18) = 0.009, p = 0.92, respectively for Low and High Intrinsic participants). (b) In contrast, Reward group participants showed greater accuracy during the puzzle performance period than did No Reward participants, regardless of intrinsic motivation status (F(1,36) = 13.6, p = .001). (c) The Reward group exhibited enhanced accuracy following incorrect, relative to correct, responses (F(1, 20) = 19.44, p < .0001), regardless of intrinsic motivation, whereas the No Reward group showed no performance facilitation (F(1,21) = .70, p = .41). Error bars show standard error of the mean.