Statistical tests and values
| Graph | Type of test | Statistical values |
|---|---|---|
| a. Fig. 2A, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (% difference in compared BSR frequencies) | p < 0.001 (25–100% difference in BSR)*F(3,45) = 13.1, p < 0.001* |
| b. Fig. 2B, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (individual frequency comparisons) | p < 0.05 (all BSR comparisons)*F(10,118) = 6.995, p < 0.001* |
| c. Fig. 2C, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (raw difference in compared BSR frequencies) | All p < 0.001 (all BSR comparisons)*F(5,37) = 3.61, p = 0.011* |
| d. Fig. 2D, number of trials completed | ANOVA (individual frequency comparisons) | F(10,118) = 2.446, p = 0.011* |
| e. Fig. 2E, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (proportionate time × % difference in BSR frequency); ANOVA (proportionate time); ANOVA (% difference in BSR frequency) | p ≤ 0.01 (all BSR comparisons)*F(27,279) = 1.346, p = 0.133F(9,279) = 5.838, p < 0.001*F(3,279) = 20.582, p < 0.001* |
| f. Fig. 2F, number of trials completed | ANOVA (proportionate time × % difference in BSR frequency); ANOVA (proportionate time); ANOVA (% difference in BSR frequency) | F(27,279) = 1.242, p = 0.205F(9,279) = 6.320, p < 0.001*F(3,279) = 1.457, p = 0.259 |
| g. Fig. 3A, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (difference in pellet number) | p < 0.001 (all pellet comparisons)*F(3,39) = 8.63, p < 0.001* |
| h. Fig. 3B, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (individual pellet comparisons within each comparison range) | p < 0.001 (1v2, 2v3, 1v3, 2v4, 1v4, 2v5, 1v5)*F(10,118) = 7.00, p < 0.001* |
| i. Fig. 3C, number of trials completed | ANOVA (individual pellet comparisons within each comparison range) | F(10,109) = 5.40, p < 0.001* |
| j. Fig. 3D, preference for larger reward | Pearson correlation | R 2 = 0.998, p < 0.0001* |
| k. Fig. 3E, preference for larger reward | z tests (50% preference; one-tailed); ANOVA (proportionate time × % difference in pellet number); ANOVA (proportionate time); ANOVA (% difference in pellet number) | p ≤ 0.05 (0.0–0.1 proportionate time)*F(27,399) = 1.509, p = 0.056F(9,399) = 25.29, p < 0.001*F(3,399) = 1.91, p = 0.152 |
| l. Fig. 3F, number of trials completed | ANOVA (proportionate time × difference in pellet number); ANOVA (proportionate time); ANOVA (% difference in pellet number) | F(27,399) = 0.878, p = 0.64F(9,399) = 112.136, p < 0.001*F(3,399) = 1.146, p = 0.349 |
| m. Fig. 4A, preference for 1 sugar pellet | z test (50% preference; one-tailed); ANOVA (proportionate BSR frequency) | p < 0.05 (0%, 50% BSR)*F(4,24) = 0.413, p = 0.80 |
| n. Fig. 4B, preference for 2 sugar pellets | z test (50% preference; one-tailed); ANOVA (proportionate BSR frequency) | p < 0.001 (0%, 25% BSR)*F(4,24) = 0.963, p = 0.449 |
| o. Total pellets earned | ANOVA (sugar pellet reward size × BSR reward size); ANOVA (sugar pellet reward size); ANOVA (BSR reward size) | F(4,49) = 1.486, p = 0.253F(1,49) = 66.31, p < 0.001*F(4,49) = 1.037, p = 0.418 |
| p. Fig. 4C, preference for 1 sugar pellet | z test (50% preference; one-tailed); ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | All p < 0.05 (0.3–1.0 proportionate time)*F(36,249) = 0.928, p = 0.59F(9,249) = 3.987, p = 0.001F(4,249) = 0.82, p = 0.531 |
| q. Fig. 4D, preference for 2 sugar pellets | z test (50% preference; one-tailed); ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | All p < 0.05 (0.6–1.0 proportionate time)*F(36,249) = 1.886, p = 0.005*F(9,249) = 10.60, p < 0.001*F(4,249) = 1.295, p = 0.314 |
| r. Fig. 4E, number of trials completed (1-pellet sessions) | ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | F(36,249) = 0.916, p = 0.608F(9,249) = 3.353, p = 0.004*F(4,249) = 1.538, p = 0.239 |
| s. Fig. 4F, number of trials completed (2-pellet sessions) | ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | F(36,249) = 1.360, p = 0.105F(9,249) = 4.673, p < 0.001*F(4,249) = 0.606, p = 0.664 |