Abstract
Introduction
Inter-individual differences in resistance to cognitive effects of sleep loss are well established and extend from basic vigilance capacities to more nuanced emotional processing. Neurobiological markers related to gray matter volumetric differences associated with resilience to sleep deprivation (SD) have yet to be explored. We collected anatomical magnetic resonance imaging on well-rested healthy adults and correlated gray matter volume (GMV) with the number of lapses on a psychomotor vigilance test (PVT) subsequently occurring over 29-hours of SD.
Methods
45 individuals (23 males; mean age: 25.36 ± 5.62y) completed a baseline neuroimaging session while well-rested and returned 2-4 days later to complete 29h of SD. The PVT was administered at one-hour intervals across SD. High-resolution T1 structural scans were used for a volume-based morphometric analysis (CAT12). Images were segmented and normalized following automated procedures and smoothed at 8 mm FWHM. Regions of interest were constrained to the anterior cingulate and ventral frontal areas of the cortex. GM volume was correlated with the total number of lapses across all PVT administrations, after controlling for age, sex, and total intracranial volume.
Results
Total number of lapses positively correlated with GMV in two clusters comprised of areas in the anterior cingulate cortex (FWE corrected, p = 0.046), as well as the opercular and triangular parts of the inferior frontal gyrus (FWE corrected, p = 0.006).
Conclusion
Susceptibility to attentional lapses was predicted by greater gray matter volume in the ventrolateral prefrontal and anterior cingulate cortices. Current findings support that individual differences in attentional resiliency during SD may be, in part, due to differences in gray matter volume within cortical areas previously shown to be functionally affected by sleep loss.
Support
DARPA (12-12-11-YFA11-FP-029)