Numerical magnitude, rather than individual bias, explains spatial numerical association in newborn chicks
- Department of General Psychology, University of Padova, Italy
- Department of Psychology, University of Pennsylvania, United States
- Center for Mind/Brain Sciences, University of Trento, Italy
Figures
Figure 1
Left Choices (LC) as a function of numerical magnitudes.
Left Choices (means, SE, 1Q and 3Q) in each test of Experiment 1 (A) and Experiment 2 (B). Dotted lines represent the chance level and dots represent the outliers, which were included in the final sample. Below, for each experiment we reported the Bayesian and the frequentist one-sample t-test vs. chance level. Experiment 1: Chicks took more left-sided choices when facing smaller magnitudes (two: BF >100; p<0.001, Cohen’s d = 1.572), and more right-sided choices when facing larger magnitudes (eight: BF >100; p<0.001, Cohen’s d = 1.505) than the one experienced during training (five); in the 5 vs. 5 test they did not show any bias (BF = 0.321; p=0.522, Cohen’s d = 0.151). Experiment 2: Chicks took more left-sided choices when facing smaller magnitudes (two: BF = 51.417; p<0.001, Cohen’s d = 1.072), and more right-sided choices when facing larger magnitudes (eight: BF = 23.070; p<0.001, Cohen’s d = 0.979) than the one experienced during training (five); in the 5 vs. 5 test they did not show any bias (BF = 0.291; p=0.863, Cohen’s d = 0.05).
Figure 2
Experimental apparatus.
Schematic representation of the apparatus used during training (A) and test (B).
Tables
Table 1
Data and results concerning the side of circumnavigation for each panel in all test conditions of both experiments (Source data 5).
| Experiment 1 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Left panel | Right panel | BF | X2 | P | Phi | ||||
| Test | Side | Left | Right | Left | Right | ||||
| 2 vs. 2 | Count | 51 | 35 | 18 | 16 | 0.301 | 0.403 | 0.525 | 0.058 |
| % | 59.302 | 40.698 | 52.941 | 47.059 | |||||
| 5 vs. 5 | Count | 41 | 22 | 25 | 32 | 3.314 | 5.444 | 0.020 | 0.213 |
| % | 65.079 | 34.921 | 43.860 | 56.140 | |||||
| 8 vs. 8 | Count | 21 | 13 | 51 | 35 | 0.249 | 0.062 | 0.804 | 0.023 |
| % | 61.765 | 38.235 | 59.302 | 40.698 | |||||
| Experiment 2 | |||||||||
| Left Panel | Right Panel | BF | X2 | p | Phi | ||||
| Test | Side | Left | Right | Left | Right | ||||
| 2 vs. 2 | Count | 62 | 22 | 20 | 16 | 1.512 | 3.880 | 0.049 | 0.180 |
| % | 73.810 | 26.190 | 55.556 | 44.444 | |||||
| 5 vs. 5 | Count | 36 | 25 | 34 | 25 | 0.224 | 0.024 | 0.877 | 0.014 |
| % | 58.333 | 41.667 | 57.626 | 42.373 | |||||
| 8 vs. 8 | Count | 24 | 16 | 23 | 57 | 49.104 | 10.930 | <0.001 | 0.302 |
| % | 60 | 40 | 28.750 | 71.250 | |||||
Table 2
Outline of the experimental procedures.
| Time | Procedures |
|---|---|
| Day 1, morning | Arrival and housing in standard conditions |
| Day 2, all day | Standard rearing conditions – no procedures |
| Day 3, from early morning to mid afternoon | Removal of Food jars (2 hr before shaping) |
| Shaping – followed by 2 hr rest | |
| Training Session 1 | |
| Test 1 – followed by 1 hr rest | |
| Training Session 2 | |
| Test 2 – followed by 1 hr rest | |
| Training Session 3 | |
| Test 3 | |
| Social housing – end of procedures |
Additional files
-
Source data 1
Figure 1A, Left Choices (LC) as a function of numerical magnitudes in Experiment 1.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data1-v1.csv
-
Source data 2
Left Choices (LC) and Order restriction: LC2vs.2>LC5 vs.5>LC8 vs.8 in Experiment 1.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data2-v1.csv
-
Source data 3
Small Number Bias (SNB) in Experiment 1.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data3-v1.csv
-
Source data 4
Large Number Bias (LNB) in Experiment 1.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data4-v1.csv
-
Source data 5
Table 1, Direction of Circumnavigation in Experiment one and in Experiment 2.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data5-v1.csv
-
Source data 6
Figure 1B, Left Choices (LC) as a function of numerical magnitudes in Experiment 2.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data6-v1.csv
-
Source data 7
Left Choices (LC) and Order restriction: LC2vs.2>LC5 vs.5>LC8 vs.8 in Experiment 2.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data7-v1.csv
-
Source data 8
Small Number Bias (SNB) in Experiment 2.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data8-v1.csv
-
Source data 9
Large Number Bias (LNB) in Experiment 2.
- https://cdn.elifesciences.org/articles/54662/elife-54662-data9-v1.csv
-
Transparent reporting form
- https://cdn.elifesciences.org/articles/54662/elife-54662-transrepform-v1.pdf
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Numerical magnitude, rather than individual bias, explains spatial numerical association in newborn chicks
eLife 9:e54662.
https://doi.org/10.7554/eLife.54662
