Grouping strategies in number estimation extend the subitizing range

In the calculation folder: each file contains a matrix called “MATR”. Each row of the matrix “MATR” is a trial. The columns contain the following information: 1^st: Number of trial 2^{nd: Subject response} 4^th: Response time 5^th: first number 6^th: math symbol (1=*; 2= +; 3= –) 7^th: second number 8^th: third number In the calculation folder: each file contains a matrix called “matr”. Each row of the matrix “matr” is a trial. The columns contain the following information: 1^st: subject response in the numerosity task 2^nd: the presented numerosity 3^rd: subject response in the numerosity task 4^th: zero 5^th: stimulus duration 6^th: Response time in the numerosity task 7^th: Grouped (1) or random (2) presentation 8^th: 1 9^th: 1 10^th: Number of items of the upper-left quadrant 11^th: Number of items of the lower-left quadrant 12^th: Number of items of the upper-right quadrant 13^th: Number of items of the lower - right quadrant 14^th: odd shape presented (1=diamond; 2=triangle; 3=circle) 15^th: subject response in the shape task 16^th: 0.2 in the single task response time in the shape task when dual task 17^th: single (0) or dual (1) task 18^th: time stimulus on 19^th: time stimulus off