The Unrested Resting Brain: Sleep Deprivation Alters Activity within the Default-mode Network

Gujar, N., Seung-Schik, Y., Hu, P., & Walker, M. P. (2010). The Unrested Resting Brain: Sleep Deprivation Alters Activity within the Default-mode Network. Journal of Cognitive Neuroscience, 22(8), 1637-1648. Retrieved from EBSCOhost

The Unrested Resting Brain: Sleep Deprivation Alters Activity within the Default-mode Network

          I chose this article because I think that the way our sleep affects us in all aspects of life, and seeing as college students are the leaders of not getting adequate sleep I found this article interesting. It is important to note that sleep deprivation not only affects our brain but all aspects of our functioning life. Many studies have been conducted on the affects of sleep deprivation on cognitive task performance. However little has been said about the affects of sleep deprivation on resting-state modes of brain activation. In this study they hypothesize that the integrity of activity within this default-mode network is dependent on a night of prior sleep. They examine whether a night of sleep of sleep deprivation disrupts the task-induced deactivation, the differences in the deactivations and their relation to on-task trial success, and whether the extent of the alterations relates to the amount of prior sleep or the duration of wakeful time. The participants in this study consisted of 28 health people both male and female. They randomly assigned into two groups, sleep deprived or sleep rested. They went without caffeine or alcohol for 72 hrs prior to study and throughout the entire study and maintained a normal sleep-wake rhythm. The study lasted a full week. The subjects performed incidental memory encoding task while undergoing an event related fMRI scan, completed a surprise recognition test, after having restful sleep. The manipulation occurred before the fMRI scan: sleep rested groupà awake during day 1 and slept on night 1, and the sleep deprived groupà were awake across day and night 1. During the fMRI session they presented 150 images, they had a time of passive visual fixation and then an “on-task” phase where they were asked to respond about the picture. They wore MRI compatible goggles to aid in detection of brain activation. The fMRI’s were analyzed using SPM2 (Statistical Parametric Mapping) and ROC (Receiver Operator Characteristics) methods. They found that task-induced deactivation in both groups within both regions was associated with the amount of prior sleep not the duration of waking consciousness.  They also found that one night of sleep loss cause  a two directional imbalance in the brain structures both anterior and posterior that are connected with the default-mode network. The imbalance occurred most prevalently in the failed task trails. The sleep-deprived brain causes problems with on-task brain activity and off-task resting state modes of brain activity. It is interesting to know that not how long we have been awake but the sleep we had prior to the period of wakefulness is what depicts our brains performance on some tasks.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883887/?tool=pubmed