Directors: Antonio M. Battro and Kurt W. Fischer
Program officer: María Lourdes Majdalani
Circadian rhythms in working memory
Circadian variations on performance may be due to changes in specific cognitive processes. Working memory is a basic cognitive process that temporarily maintains information necessary for the execution of many complex tasks such as reading comprehension, learning and reasoning. Working memory includes two storage components: phonological (crucial for processing verbal information) and visuospatial (crucial for the analysis of visual tasks); and a central executive control. The objective of this study was to identify circadian rhythms in phonological and visuospatial storage components of working memory using a constant routine protocol. Eight female undergraduate students, aged 17.5±0.93, range=16-19 years old, were recorded in a constant routine protocol during 30 h. Rectal temperature was recorded every minute; subjective sleepiness and tiredness, as well as phonological and visuospatial working memory tasks were assessed each hour. There were circadian variations in correct responses of phonological and visuospatial working memory tasks. The phonological task showed higher amplitude. This result may explain the changes in performance of many complex tasks during the day, especially in verbal tasks.