Schematic drawing of FPCT procedure and measuring the non-cagemate male mice based on the winning/losing outcomes of FPCT.

(A) The overall procedure of FPCT experiment. (B) Habituation to the arena where the mice entered alternately from left and right sides. (C) Training to find food pellet without the existence of the movable block. (D) Training to get the food pellet placed under the movable block. (E) Statistical data of latency of food-getting (the time from entering the arena to eat the food) showing the progress of training in (D). paired Student’s t test, n = 16, n.s. stands for non-significant difference. (F) Direct win-lose test via analyzing food occupation (test 1). (G) Indirect win-lose test via analyzing mouse’s attempt to gain the food (test 2). (H) Eight single-housed mice were numbered and randomly divided into group A and B after being trained. One of the mice in group A matched only once with one of the mice in group B in the 4 days of test 1. The number listed on the left-right indicated the corresponding mice would enter the arena from left-right entry. Score 1 and 0 indicated winning and losing the food competition, respectively. (I) Heatmap showing the outcomes food competition of the non-cagemate male mice ranked with FPCT. (J) Average score of the two groups acquired in the competition. Unpaired Student’s t test = 4, n.s. stands for non-significant difference.

Ranking the 2-cagemate male mice with FPCT and tube test.

(A) Statistical data showing the latency of food-getting from the last day of training until the end of the test 1. Two-way ANOVA multiple comparisons, n = 16 pairs, n.s. stands for non-significant difference. (B) 1 of the 16 pairs of cagemate male mice exhibited alternating winning/losing outcome in FPCT test 1. (C) 15 of the 16 pairs of male mice exhibited fully congruent winning/losing outcome in FPCT test 1. (D) Statistics of ranking of male mice over through 4 trials (1 trial daily) of FPCT test 1. Two-way ANOVA, n = 16, ****P < 0.0001. (E) Average rate of consistency within trials. For each pair, rate of consistency was calculated as the percentage of the number of trials (in all 4 trials) resulting in the outcome same as the 4th trial (n = 16). (F) Statistics of duration spent on pushing block in FPCT test 2. The winner or loser identity was determined by the last trial of test 1. Paired Student’s t test, *P < 0.05, n = 16. (G) Body weight of male mice measured after FPCT. Unpaired Student’s t test, n.s. stands for non-significant difference, n = 16. (H) Timeline of experiments showing tube test was conducted after FPCT. (I) Heatmap showing the outcomes of social competition of paired male mice ranked with FPCT and tube test. (J) Statistics of ranking of male mice over through 4 trials (1 trial daily) of tube test. Two-way ANOVA, n = 16, ****P < 0.0001.

Ranking the 2-cagemate female mice using FPCT, tube test and warm spot test (WST).

(A) Statistical data showing the latency of food-getting from the last day of training until the end of the test 1. Two-way ANOVA multiple comparisons, n = 10 pairs; *P < 0.05, **P < 0.01, n.s. stands for non-significant difference. (B-D) 3 of the 10 pairs of cagemate female mice exhibited alternating winning/losing outcome in FPCT test 1. (E) 7 of the 10 pairs of female mice exhibited fully congruent winning/losing outcome in FPCT test 1. (F) Statistics of ranking of female mice over through 4 trials (1 trial daily) of FPCT test 1. Two-way ANOVA, n = 10, ****P < 0.0001. (G) Average rate of consistency within trials. For each pair, rate of consistency was calculated as the percentage of the number of trials (in all 4 trials) resulting the outcome same as 4th trial (n = 10). (H) Statistics of duration spent on pushing block in FPCT test 2. The winner or loser identity was determined by the last trial of test 1. Paired Student’s t test, *P < 0.05, n = 10. (I) Body weight of female mice measured after FPCT. Unpaired Student’s t test, n.s. stands for non-significant difference, n = 10. (J) Timeline of experiments showing tube test and warm spot test were conducted after FPCT. (K) Statistics of ranking of female mice over through 4 trials (1 trial daily) of tube test. Two-way ANOVA, n = 10, ****P < 0.0001. (L) Schematic of the warm spot test. (M) Cumulative duration of mice occupying the warm spot. The winner or loser identity was determined by the last trial of FPCT. Paired Student’s t test, n = 10, *P < 0.05. (O) Heatmap showing the outcomes of social competition of paired female mice ranked with FPCT, tube test and WST. (P) Rate of consistency between FPCT and tube test (day 4 vs day 5), FPCT and WST (day 4 vs day 9), as well as tube test and WST (day 8 vs day 9). One-way ANOVA test, n = 10, n.s. stands for non-significant difference.

Ranking the triads of male mice using FPCT, tube test and WST.

(A) Timeline of experiments to rank 3-cagemate male mice using FPCT, tube test and WST sequentially. In the FPCT and tube test, the mice contested in a round-robin style within the each 3-cagemate group. (B-G) 7 of the 10 groups of male mice exhibited alternating winning/losing outcome during the whole competition tasks. (H) 3 of the 10 groups of male mice exhibited fully congruent winning/losing outcome during the whole competition tasks. (I) Statistics of ranking of mice over through the whole competition tasks. Two-way ANOVA test, n = 10, ++++P < 0.0001 comparing FPCT and tube test, ****P < 0.0001 comparing FPCT and tube test, ####P < 0.0001 comparing tube test and WST. (J) Rate of consistency between FPCT and tube test (day 4 vs day 5), FPCT and WST (day 4 vs day 9), as well as tube test and WST (day 8 vs day 9). One-way ANOVA test, n = 10, n.s. stands for non-significant difference. (K) Heatmap showing the ranking outcomes of grouped male mice during the whole competition tasks.

Photographs of food pellet competition test (FPCT) setup.

(A) Frontal view of FPCT setup. (B) Side view of FPCT setup.

Schematic illustration of the assembling of the FPCT setup.

(A-B) Depiction of the work pieces (A) to make up the main body of the arena (B). (C-E) Depiction of the work pieces (C) to make up the movable block (D) attached to the pulley system and the roof (E). (F) Cartoon demonstrating the FPCT setup and working model with the existence of food pellet and camera. (G) Detailed list of the work pieces and parts of the FPCT setup.

Schematic drawing to show a tip to reduce the friction between the pulley and the track.

Schematic drawing to show the marking of the starting state when the mouse’s four legs just entered the chamber arena.