A Review on Stanislas Dehaene’s Model of How the Brain Thinks & Hierarchical Model of Conscious Processing and Metacognition

This review explores conscious processing and metacognition through the framework of Stanislas Dehaene’s Global Neuronal Workspace (GNW) theory, as articulated in his book Consciousness and the Brain. While Dehaene provides a compelling model of how thoughts are generated, maintained, and encoded in the brain, this paper proposes a hierarchical extension that incorporates metacognition as a distinct and dynamic component of cognitive architecture. The model comprises three interacting layers: (1) a Sensory Integration Layer in the parietal and temporal association cortices that unconsciously processes multisensory input and forms semantic associations, functioning like the input layer of an autoencoder; (2) an Intermediate Encoding Layer in deeper association areas or prefrontal cortex that transmits abstracted concepts and beliefs, akin to the bottleneck of a UNet-like structure; and (3) a Metacognitive Layer, located in the frontopolar and dorsolateral prefrontal cortex, which actively evaluates, modulates, and reconfigures lower-level processing, influencing cognitive strategies and behavioral outcomes. This integrative model emphasizes the role of metacognition not merely as confidence estimation but as a top-down agent capable of shaping perception, cognition, and action through flexible, context-sensitive modulation.