Visuoaffective day residue in hypnagogia involves sequential bihemispheric interactions between cortical, subcortical, and cerebellar structures.

Abstract

The intricate interplay between visual perception and emotion determines how waking experience influences mentation through a 'day residue' at once conspicuous yet hard to predict. Here we set out to map the neural sources associated with the visuo-affective processing of the 'day residue' during hypnagogic sleep. To this end, we assessed 28 healthy participants on a combined nap protocol with serial awakenings, pre-sleep stimulation with affective visual images, yoked measures of the semantic similarity between image and imagery reports, affect ratings, estimation of 64-channel EEG sources, and functional connectivity analysis. Overall, low-frequency EEG power was associated with weaker residues, and high-frequency EEG power was associated with stronger residues. The source networks most significantly correlated with imagetic and affective residues were markedly different across wake-sleep states, partially overlapping with the default mode network during N1 for up to 50% and 61%, respectively. The results allowed us to identify neural correlates of the visuo-affective processing of the day's residue, showing that the hypnagogic processing of the waking experience involves complex, dynamic and sequential bi-hemispheric interactions among multiple cortical, subcortical, and cerebellar structures with visual, limbic, optokinetic, and cognitive functions.