Task design and analysis methods.

(A) Movie structure. A 6.5-minute short film was created by editing fragments from Pippi on the Run into a coherent narrative. The movie consisted of 13 interleaved blocks of videos accompanied by speech or music. (B) Data analysis schematic. Standard analysis pipeline for extracting emotion features from the movie and constructing encoding model to predict iEEG responses while participants watching the short film.

Prediction performance of encoding models in DLPFC.

(A) Spatial distribution of electrodes in DLPFC. Electrodes in all participants from each group are projected onto MNI space and shown on the average brain. Red shaded areas indicate middle frontal cortex provided by the FreeSurfer Desikan-Killiany atlas (Desikan et al., 2006). Electrodes outside DLPFC are not shown. (B) Averaged prediction accuracy across participants for speech condition. The performance of encoding model is measured as Pearson correlation coefficient (r) between measured and predicted brain activities. (C) Averaged prediction accuracy across participants for music condition. (D) Prediction accuracy difference between speech condition and music condition for each group. Error bars are standard error of the mean. *P<0.05.

Prediction performance of encoding models in pSTC.

(A) The electrode distribution in the native brain space for the four children. Electrodes in pSTC are green, and electrodes in DLPFC are yellow. (B) Prediction accuracy of encoding models in children. Bars indicate mean prediction accuracy across participants and lines indicate individual data. Prediction accuracy of encoding models for S19 in both DLPFC and pSTC. (D) Spatial distribution of recording contacts in post-childhood participants’ pSTC. The pSTC electrodes identified in individual space are projected onto MNI space and shown on the average brain. Contacts other than pSTC are not shown. Blue shaded areas indicate superior temporal cortex provided by the FreeSurfer Desikan-Killiany atlas (Desikan et al., 2006). (E) Averaged prediction accuracy across postchildhood participants. Error bars are standard error of the mean. **P<0.01. *P<0.05.

Correlation between encoding weights and age.

(A) Leb: Correlation between averaged encoding weights of five complex emotions and age. Right: Correlation between averaged encoding weights of six basic emotions and age. (B) Pearson correlation coefficient between encoding weights of 48 facial expression features and age. The results are ranked from largest to smallest. Significant correlations noted with *(P<0.05, uncorrected) or **(P<0.01, uncorrected). (C) Correlation between encoding weights of embarrassment, pride, guilt, interest and age (N=12).

Demographic information of childhood group.

Demographic information of post-childhood group.