Figure 1.

Schematic depiction of the predictive coding architecture. (A) Assumed hierarchical cortical organization of predictive estimators. Note how predictions are conveyed from higher to lower cortical areas via (anatomical) feedback connections, while prediction error signals are propagated from lower to higher cortical areas via feedforward connections. (B) Simplified depiction of a canonical microcircuit as assumed within the predictive coding literature; see main text for details. Note that, anatomically, each of the predictive estimator levels in (A) is thought to be instantiated by cortical microcircuitry as shown in (B). (A) Was adapted with permission from Bornkessel-Schlesewsky et al. (2015); (B) was adapted and simplified from Bastos et al. (2012).