%0 Journal Article
%T Increased cerebral blood flow in the right frontal lobe area during sleep precedes self-awakening in humans
%A Aritake Sayaka
%A Higuchi Shigekazu
%A Suzuki Hiroyuki
%A Kuriyama Kenichi
%J BMC Neuroscience
%D 2012
%I BioMed Central
%R 10.1186/1471-2202-13-153
%X Background Some people can subconsciously wake up naturally (self-awakening) at a desired/planned time without external time stimuli. However, the underlying mechanism regulating this ability remains to be elucidated. This study sought to examine the relationship between hemodynamic changes in oxyhemoglobin (oxy-Hb) level in the prefrontal cortex and sleep structures during sleep in subjects instructed to self-awaken. Results Fifteen healthy right-handed male volunteers with regular sleep habits participated in a consecutive two-night crossover study. The subjects were instructed to wake up at a specified time (¡°request¡± condition) or instructed to sleep until the morning but forced to wake up at 03:00 without prior notice (¡°surprise¡± condition). Those who awoke within ¡À 30 min of the planned waking time were defined as those who succeeded in self-awakening (¡°success¡± group). Seven subjects succeeded in self-awakening and eight failed. No significant differences were observed in the amounts of sleep in each stage between conditions or between groups. On the ¡°request¡± night, an increase in oxy-Hb level in the right prefrontal cortex and a decrease in ¦Ä power were observed in the ¡°success¡± group around 30 min before self-awakening, whereas no such changes were observed in the ¡°failure¡± group. On the ¡°surprise¡± night, no significant changes were observed in oxy-Hb level or ¦Ä power in either group. Conclusions These findings demonstrate a correlation between self-awakening and a pre-awakening increase in hemodynamic activation in the right prefrontal cortex, suggesting the structure¡¯s contribution to time estimation ability.
%K Time estimation ability
%K Self-awakening
%K Sleep
%K Cognitive science
%K Prefrontal cortex
%K Insomnia
%U http://www.biomedcentral.com/1471-2202/13/153