Dream Recall Frequency Is Associated With Medial Prefrontal Cortex White-Matter Density.

People who frequently recall dreams have denser white matter in the medial prefrontal cortex (MPFC) than those who rarely recall dreams. Using brain scans of 46 high dream recallers (who recalled dreams about six mornings per week) and 46 low dream recallers (who recalled dreams less than once per week), researchers found no differences in gray or white matter density in the temporo-parietal junction, hippocampus, or amygdala. The finding aligns with evidence that damage to MPFC white matter can stop dream reporting, suggesting this region plays a role in dream recall or production.

Study at a glance

Abstract

Recent findings indicate that dream recall frequency (DRF) is associated with neurophysiological traits, and notably the regional cerebral blood flow at rest within the medial prefrontal cortex (MPFC) and the temporo-parietal junction (TPJ). To test whether, such physiological traits are rooted in anatomical specificities, we used voxel-based morphometry to compare the white matter and gray matter density in regions related to dream recall (either at the experimental or theoretical level, MPFC, TPJ, hippocampus and amygdala) between 46 high dream recallers (HR, DRF = 5.98 ± 1.25 days per week with a dream report) and 46 low dream recallers (LR, DRF = 0.34 ± 0.29). We found an increased medial prefrontal cortex white-matter density in HR compared to LR but no other significant difference between the two groups. These results are consistent with previous studies showing that lesions within the white matter of medial prefrontal cortex are associated with a partial or total cessation of dream reporting and suggest an implication of this region in dream recall or, more likely, in dream production.