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Numerical magnitude, rather than individual bias, explains spatial numerical association in newborn chicks

  1. Rosa Rugani  Is a corresponding author
  2. Giorgio Vallortigara
  3. Konstantinos Priftis
  4. Lucia Regolin
  1. Department of General Psychology, University of Padova, Italy
  2. Department of Psychology, University of Pennsylvania, United States
  3. Center for Mind/Brain Sciences, University of Trento, Italy
Research Article
Cite this article as: eLife 2020;9:e54662 doi: 10.7554/eLife.54662
2 figures, 2 tables and 10 additional files

Figures

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).

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 panelRight panelBFX2PPhi
TestSideLeftRightLeftRight
2 vs. 2Count513518160.3010.4030.5250.058
%59.30240.69852.94147.059
5 vs. 5Count412225323.3145.4440.0200.213
%65.07934.92143.86056.140
8 vs. 8Count211351350.2490.0620.8040.023
%61.76538.23559.30240.698
Experiment 2
Left PanelRight PanelBFX2pPhi
TestSideLeftRightLeftRight
2 vs. 2Count622220161.5123.8800.0490.180
%73.81026.19055.55644.444
5 vs. 5Count362534250.2240.0240.8770.014
%58.33341.66757.62642.373
8 vs. 8Count2416235749.10410.930<0.0010.302
%604028.75071.250
Table 2
Outline of the experimental procedures.
TimeProcedures
Day 1, morningArrival and housing in standard conditions
Day 2, all dayStandard rearing conditions – no procedures
Day 3, from early morning to mid afternoonRemoval 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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