Fig. 4. PCA results.

(A) Results from an analysis of the data reported by Shibata et al., in 2011 in which the early visual cortex (V1 and V2) was targeted. (B) Results from an analysis of the data reported by Amano et al., in 2016 in which the early visual cortex (V1 and V2) was targeted. (C) Results from an analysis of the data reported by Koizumi et al., in 2016 in which the early visual cortex (V1 and V2) was targeted. (D) Results from an analysis of the data reported by Shibata et al., in 2016 in which the cingulate cortex was targeted. (E) Results from an analysis of the data reported by Cortese et al., in 2016 in which the parietal and frontal cortices were targeted. (F) Summary of the five studies. The red and blue bars represent the results of the induction and decoder construction (DC) stages, respectively. The magenta bars show the results of the PCA in which transformation loadings were computed from fMRI data in the DC stage and proportions of PCs accounting for 80% of the variance (PC_80%) were calculated from fMRI data obtained from the entire period of the induction stage (DC → Induction PCA). The results of the DC → Induction PCA indicate that if PC_80% is significantly less than 80%, fMRI signal patterns in the Induction stage contain subcomponents of fMRI signal patterns in the DC stage. In all PCAs for each study, PC_80% was significantly less than 80% (two-tailed one-sample t-test, P < 10^–4). Black lines in the box plots represent median values. Areas with darker colors indicate 95% confidence intervals and areas with lighter colors indicate 1 SD. Gray dots show individual data points.