Insight and executive functions in acquired brain injury: empirical evidence and theoretical frameworks

Impaired self-awareness affects 30-50% of patients with moderate to severe acquired brain injury (ABI) and represents one of the most clinically consequential obstacles to effective rehabilitation. Despite substantial evidence that self-awareness and executive functions share neural substrates in prefrontal cortex, the mechanisms linking these two functions remain incompletely specified. This paper reviews the empirical evidence for the relationship between executive functions and insight in ABI, and evaluates four theoretical frameworks: the Cognitive Awareness Model, the Dynamic Comprehensive Model of Awareness, Mograbi et al.'s predictive coding framework, and Duncan's adaptive coding model. It then proposes a novel integration of the latter two as a mechanistically grounded account of why executive dysfunction and impaired self-awareness co-occur following prefrontal damage. We argue that adaptive coding describes the representational flexibility of prefrontal neurons in coding self-relevant information, whilst predictive coding provides the computational logic, driven by precision-weighted prediction errors, through which this adaptive selection is updated. We conclude by discussing assessment and rehabilitation implications in ABI.