Abstract
The role of REM sleep in VPL has remained elusive. We have previously found that both REM sleep and wakefulness stabilize VPL: If two different types of visual training occur successively with no interval, the first VPL training is retrogradely interfered with by the second VPL (Seitz et al, 2005; Yotsumoto et al, 2009). However, if REM sleep or wakefulness occurs during the interval, no retrograde interference was observed, indicating that REM sleep and wakefulness allow VPL to stabilize. Does this indicate that REM sleep and wakefulness have the same role in VPL? To address this question, we examined whether both REM sleep and wakefulness between the first and second types of visual training eliminate anterograde interference (from first on second VPL) as well as retrograde interference (from first on second VPL). Two blocks of training on the texture discrimination task with orthogonal orientations of background lines (1st-TDT and 2nd-TDT) were separated by a 2-hr interval. During the interval, subjects either slept (sleep group, n=12) or stayed awake (wake group, n=9). Performance was measured before and after trainings for both 1st-TDT and 2nd-TDT. The results showed that no retrograde interference occurred in the subjects from the wake group and those who showed REM sleep from the sleep group (REM-present), consistent with our previous findings. However, anterograde interference was observed for the wake group, but not for the REM-present group. Moreover, the amount of VPL of the 2nd-TDT was significantly correlated with the REM-sleep duration. These results suggest that REM sleep facilitates new VPL after sleep by eliminating anterograde interference from pre-sleep VPL. It has been reported that REM sleep prunes newly formed but unnecessary dendritic spines, which leaves room for the formation of even newer spines. This spine dynamics during REM sleep could account for the current results.
Meeting abstract presented at VSS 2018