Neurobehavioral and Cognitive Changes Induced by Sleep Deprivation in Healthy Volunteers.

To this day, the pharmacological treatment of Alzheimer's disease remains limited to the temporary stabilisation of cognitive decline and the reduction of neuropsychiatric symptoms. It is moreover with great difficulty to predict and select promising drug candidates in the early stages of the discovery and developmental process. In this context, scientists have developed new experimental paradigms to artificially induce transient cognitive impairments in healthy volunteers akin to those observed in Alzheimer's disease, i.e. the Cognitive Challenge Models. In the last decade, a great amount of literature on Sleep Deprivation was published which mainly focused on the consequences of sleep loss for public health. However, sleep deprivation paradigm may also be regarded as a cognitive challenge model. It is commonly accepted that sleep deprivation induces cognitive impairments related to a global decrease in vigilance, while in fact, there is a controversial approach related to the selective effects on cognitive functions. The identification and validation of cognitive challenge models in healthy volunteers are suitable in early clinical development of drugs to determine the 'hint of efficacy' of drug candidates. The present review aims at exploring in detail the methods, designs and cognitive paradigms used in non pharmacological sleep deprivation studies. Sleep deprivation can be induced by different methods. Probing the four main cognitive functions will allow identifying the extent to which different sleep deprivation designs selectively compromise executive function, working memory, episodic memory and attention. Findings will be discussed in line with cognitive processing levels that are required according to the tasks.