Neural Networks of Unconscious Processes: A Systematic Review of Functional Connectivity in Dreams and Free Association
Cureus February 1, 2026 Héctor Aceituno, Juan José Valero, Luisana Maldonado-De Santiago et al.
This systematic review of 28 neuroimaging studies finds that dreaming and free association of ideas share common neural circuits. Both processes activate the default mode network, including the medial prefrontal cortex, posterior cingulate cortex, and precuneus. During REM sleep, the amygdalo-hippocampal complex is hyperactivated while the dorsolateral prefrontal cortex is functionally disconnected. Free association shows similar patterns, with activation of the anterior temporal lobe and angular gyrus and reduced prefrontal modulation. Prefrontal deactivation allows expression of associations from deep semantic networks, released from executive control. These findings provide neurobiological foundations for neuropsychoanalysis and suggest therapeutic targets for disorders of unconscious processing.