The Effect Of Sleep Deprivation On The Inhibitory Control Ability

Inhibitory control ability is an important component of executive function of brain.Commonly,inhibitory control ability is measured with the go/no-go task.Sleep deprivation results in the loss of inhibitory control ability.The extent of decline in this ability varies across individuals.Some studies used functional magnetic resonance imaging and the go/no-go task to study the neural correlates of sleep deprivation induced differences in this ability.Usually,these studies paid more attention to the effect of 24 h of sleep deprivation on the neural processes involved in the changes in inhibitory ability.There were two problems need to be paid more attention to: First,the go/no-go task was limited in terms of behavioural measures of the inhibitory process;Second,although the activation in brain regions about the effect of 24 h sleep deprivation on inhibitory control ability had been studied deeply,an assessment of the change of the activation of brain regions during sleep deprivation is currently not available.In the current thesis,we used the stop signal task to study the effect of sleep deprivation on the inhibitory control ability and the correlation between microstructural properties of white matter and the damage degree of inhibitory control ability during sleep deprivation.The stop signal task can provide a behavioural measure of the inhibitory process,that is the stop signal reaction time,referred to as SSRT.The smaller SSRT represents the better inhibitory control ability.In order to study the change of the activation of brain regions during sleep deprivation,we adopt the repeated measurement of experiment design.All participants took part in two scanning sessions,rested wakefulness and sleep deprivation.Each participant have completed four times functional magnetic resonance imaging scanning.The scanning at rested wakefulness took place at 8:00 A.M.,labeled as T(0),representing 0h of sleep deprivation.For the sleep deprivation session,there were three times scanning during the 24 h of sleep deprivation,at 10:00 P.M.the night of sleep deprivation,labeled as T(14),representing 14 h of sleep deprivation;at 4:00 A.M.the next morning,labeled as T(20),representing 20 h of sleep deprivation;and at 8:00 A.M.the next morning,labeled as T(24),representing 24 h of sleep deprivation.Through the analysis of the behavior data,we found the ability to respond correctly to go signal(simple attention and response speed)was began significantly affected by sleep deprivation at T(20).It was noted that,participants were began significantly impaired in their ability to withhold responses to the stop signal at T(14).These findings suggested that inhibitory control ability declined early in the course of sleep deprivation,and maybe inhibitory control ability is a kind of high level cognitive control that is sensitive to sleep deprivation.For the functional magnetic resonance imaging data,we found the change of the activation of brain regions during sleep deprivation exhibited roughly four trends:1.Two type of activated state,namely the normal state and the sleep deprivation damage state.2.Activation exhibited monotony decline as the sleep deprivation time.3.Activation intensity was the lowest at T(20).4.Activation intensity was the highest at T(14).Further,we studied the relationship between the activation of brain regions and inhibitory control ability at different time points during sleep deprivation.It was possible that the stronger activation of left of ACC at T(14)and T(20),and the stronger activation of right of middle temporal gyrus at T(14),maybe were benefit for the inhibitory control ability.For the diffusion tensor imaging data,we found the microstructural property of white matter,fractional anisotropy,was correlated with the damage degree of inhibitory control ability after 24 h of sleep deprivation.Higher fractional anisotropy values in the left of posterior thalamic radiation,left of posterior corona radiata and left of retrolenticular part of the internal capsule all seemed to be associated with the lower degree of inhibitory control ability damage after 24 h of sleep deprivation.Differences in white matter structure may help explain individual differences in vulnerability of inhibitory control ability to sleep deprivation.