The folder Data contains two subfolders one for Baseline data and one for Adaptation data. Each subfolder contains Raw EEG traces (.set and .fdt files) and Raw Behavioral data (.mat files) of each participant. Behavioral Data Consist of a table (“Tbase” for Baseline and “Tadapt” for Adaptation) with each column reporting the following information: 1st column: Numerosity of the test stimulus. 2nd column: Side of presentation (in Baseline trials: 1 = Left; 2 = Right; in Adaptation trials: 1 = Adapted condition; 2 = Unadapted condition). 3rd column: Response request (1 meaning “yes” and 0 meaning “no”) 4th column: Response 5th column (only in Adaptation): Adaptors’ arrangement: 1 = High Adaptor on the left and Neutral Adaptor on the right; 2 = High Adaptor on the right and Neutral Adaptor on the left EEG Data All EEG traces contain labeled triggers following this code: Baseline traces: “Side” (Left or Right) – “Numerosity” Adaptation traces: “Condition” (AdaptSX, UnadaptSX, AdaptDX, UnadaptDX) – “Numerosity”. Legend for the adaptation conditions: AdaptSX: test stimulus being presented in the left side when the real adaptor appeared on the left side UnadaptSX: test stimulus being presented in the right side when the real adaptor appeared on the left side AdaptDX: test stimulus being presented in the right side when the real adaptor appeared on the right side UnadaptDX: test stimulus being presented in the left side when the real adaptor appeared on the right side Trigger 1: appearance of the two Adaptors