Two-dimensional (2D) correlation analysis has been used to investigate the calorimetric glass transition of neat polystyrene (PS) and poly(methyl methacrylate) (PMMA) as well as their blends. The normalized heat capacity (C-P(N)), assimilated to the temperature derivative of the fictive temperature, was used as a rational framework for the 2D correlation computation. The glass transition dynamic was explored using cooling and heating rates as an external "perturbation". First, the applicability of the 2D correlation analysis was investigated regarding the nonlinearity of the calorimetric glass transition phenomenology. Second, a comparison between simulated C-P(N) data, using the Tool-Narayanaswamy-Moynihan model, and experimental data obtained via differential scanning calorimetry distinguished the cross-peak patterns associated with the instrument effect from those related to the glass transition phenomenology. Finally, the overlapped glass transitions of PS and PMMA blends were used as a model in order to evaluate the elucidation power of the 2D correlation analysis.