Fig. 4

A flow diagram of three prediction error correlation (r) statistics. The group average r (r_{_}GrpAve) is shown in A. A1: Prediction error variance (PEV) matrix of seven individuals. A2: Calculate the mean of prediction error variance / covariance within the unit (PEV_{_}mean) and mean of prediction error covariance across the unit (PEC_{_}mean). A3: Group average r is a correlation calculated from PEV_{_}mean and PEC_{_}mean. The calculation of individual average r (r_{_}IdAve) involving seven individuals is displayed in B. B1: Prediction error variance (PEV) matrix of seven individuals. B2: Calculate pairwise correlation coefficients of individuals between units using PEV and prediction error covariance (PEC). Subscripts i and j refer to the ith and jth individuals in units 1 and 2, respectively. B3: Individual average r is calculated as the average of pairwise prediction error correlation coefficients of individuals across units. The r of contrast (r_{_}Contrast) is shown in C. r_{_}Contrast is calculated from the product of the transpose of the contrast vector (x), r matrix, and the contrast vector