Fig 1.
The LL Sudoku (LL) is indicated by green edges. Initial filled-in cells had a gray-colored background. After a block ends, it continues to a screen which asks participants to fill in the subjective ratings. A video distractor is played continuously in the top right of the screen.
Fig 2.
The subjective measure of fatigue and effort.
(A) Average fatigue scores for each block using the VAS. The y-axis shows subjective fatigue scores from 0 to 100. (B) Average effort ratings for each block using the RSME. The y-axis shows the subjective mental effort scores from 0 to 150. All x-axes show blocks, where odd blocks represented by square markers are the low motivation blocks. Error bars in each block represent standard errors.
Table 1.
The mixed-effect result of the subjective measure of fatigue and effort from the best fitted model.
Fig 3.
(A) Average score of mental demand for each block. (B) Average score of physical demand for each block. (C) Average score of temporal demand for each block. (D) Average score of performance for each block. (E) Average score of subjective effort for each block. (F) Average score of frustration level for each block. All figures’ y-axes show the score for each scale from 0 to 100, and x-axes show blocks, where odd blocks represented by square markers are the low motivation blocks. Error bars in each block represent standard errors.
Table 2.
The mixed-effect results of NASA-TLX from the best fitted model.
Fig 4.
(A) Average response time for each block. (B) Average accuracy for each block. (C) The number of clicks for each block. All figures’ y-axes show their value respectively, and x-axes show blocks, where odd blocks represented by square markers are the low motivation blocks. Error bars in each block represent standard errors.
Table 3.
The mixed-effect result of performance measures from the best fitted model.
Fig 5.
Average power of HRV in the MF band.
The y-axis shows the normalized value of the MF power. The x-axis shows blocks, where odd blocks represented by square markers are the low motivation blocks. Error bars in each block represent standard errors.
Table 4.
The mixed-effect result of MF power from the best fitted model.
Fig 6.
Pupil diameter and visual distraction.
(A) Average pupil diameter for each block. (B) Average visual distraction frequency for each block. (C) Average visual distraction duration for each block. All figures’ y-axes show their value respectively, and x-axes show blocks, where odd blocks represented by square markers are the low motivation blocks. Error bars in each block represent standard errors.
Table 5.
The mixed-effect result of pupillometry measures from the best fitted model.
Fig 7.
(A) Average eyeblink frequency for each block. (B) Average eyeblink duration for each block. (C) Average saccades frequency for each block. (D) Average saccades amplitude for each block. All figures’ y-axes show their value respectively, and x-axes show blocks, where odd blocks represented by square markers are the low motivation blocks. Error bars in each block represent standard errors.
Fig 8.
The results comparison between the study of the extrinsic motivation experiment represented by a dashed line and the intrinsic motivation experiment represented by a solid line.
(A) Fatigue scale (B) MF power of HRV (C) Pupil diameter (D) Visual distraction frequency. All x-axes show blocks, where odd blocks represented by square markers are the low motivation blocks (nonreward condition in the extrinsic motivation experiment and LL condition in the intrinsic motivation experiment). The figures of the extrinsic motivation experiment were adapted from Herlambang et al. [9]. Creative Commons License (CC BY-NC 4.0).