Abstract
Visual perpetual learning (VPL) is defined as a long-term performance improvement on a perceptual task as a result of perceptual experience. It has been found that sleep strengthens and consolidates VPL. In addition to the effect of sleep, reinforcement given through external primary reward (such as water) has been found to facilitate VPL. However, it is not clear whether sleep and reward independently influences VPL or whether there is a mechanism in which the effect of reward on VPL is particularly enhanced during sleep. To test which model is more plausible, we investigated whether reward and sleep interacts on VPL using a widely utilized VPL paradigm known as the texture discrimination task (TDT). In the standard TDT, participants report the orientation of an array of oblique lines embedded in a field of all vertical or all horizontal lines. Robust over-night improvement has been demonstrated. In the present study, we trained 32 water-deprived participants on TDT at either 9-10am (no sleep included) or 9-10pm (sleep included) and then retested their performance 12 hours later. Half of the subjects received auditory feedback and water as reward through a tube for a correct response while the other half only received auditory feedback for a correct response. Thus, there were 4 groups in total; no-sleep-with-reward, no-sleep-without-reward, sleep-with-reward, and sleep-without-reward groups. Our results show a strong tendency for sleep-dependent performance improvement especially within the group that was rewarded for correct performance with water. This interaction between sleep and reward on VPL suggests that sleep has a specialized mechanism for consolidating reward-based VPL, compared to regular forms of VPL.
Meeting abstract presented at VSS 2015