Takano K, et al. - Researchers, in the present study, investigated the following as two possible mechanisms underlying pre-sleep cognitive arousal: attention bias towards sleep-related stimuli and; difficulty in updating working memory for sleep-related stimuli. They examined the bias by the dot-probe and n-back tasks with sleep-related stimuli. Results showed that attention bias and sleep problems were not associated. People with pre-sleep worry were even more efficient at processing sleep stimuli. In those individuals, sleep information could be processed without cognitive effort.