Abstract
Humans are typically unable to engage in sustained smooth pursuit for imagined objects. However, it is unknown to what extent smooth tracking occurs for visual imagery during REM sleep dreaming. Here we examine smooth pursuit eye movements during tracking of a slow-moving visual target during lucid dreams in REM sleep. Highly similar smooth pursuit tracking was observed during both waking perception and lucid REM sleep dreaming, in contrast to the characteristically saccadic tracking observed during visuomotor imagination. Our findings suggest that, in this respect, the visual imagery that occurs during REM sleep is more similar to perception than imagination. The data also show that the neural circuitry of smooth pursuit can be driven by a visual percept in the absence of retinal stimulation and that specific voluntary shifts in the direction of experienced gaze within REM sleep dreams are accompanied by corresponding rotations of the physical eyes.
Highlights
Humans are typically unable to engage in sustained smooth pursuit for imagined objects
Since smooth pursuit eye movements (SPEMs) elicited during visual tracking are known to depend on visual motion signals, they may be used as an objective assessment of visual imagery during rapid eye movement (REM) sleep
Our data provide evidence that intentional slow tracking of visual motion during REM sleep dreams results in SPEMs that are highly similar to waking perception, suggesting that, in this respect, the visual quality of imagery during REM sleep dreaming is more similar to waking perception than imagination
Summary
Humans are typically unable to engage in sustained smooth pursuit for imagined objects. We perform an objective test of this question by determining the extent to which smooth pursuit eye movements (SPEMs) are observed when an individual tracks a slow-moving visual target during lucid rapid eye movement (REM) sleep dreaming. As during waking perception, REMs are associated with transient modulation of spiking activity in the medial temporal lobe associated with visual-mnemonic processes[8] Together, this evidence suggests that there are multiple sources of eye movements in REM sleep, a subset of which include correspondence between dreamed gaze direction and eye movements. Precise psychophysiological correlations were made possible by participants marking the exact moments of initiation of lucidity and the initiation and completion of the tracking tasks with volitional left–right–left–right (LRLR) eye movement signals[7]. Our data provide evidence that intentional slow tracking of visual motion during REM sleep dreams results in SPEMs that are highly similar to waking perception, suggesting that, in this respect, the visual quality of imagery during REM sleep dreaming is more similar to waking perception than imagination
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
