Jacob, given that Fortier-Brochu et al. published a meta-analysis in 2012, you would need to provide a good argument for why a new review in 2015 is required. One reason might be that there has been an explosion of research in this field which needs reviewing systematically. Another may be that your question is different from that posed by Fortier-Brochu. Perhaps you wish to focus, in depth, on a particular aspect of cognition. For example, you may wish to review just the literature on episodic memory deficits. If there are sufficient studies, you could then divide the papers by type of episodic memory (e.g. visual, verbal, visuo-spatial, or learning, cued-recall, free-recall, recognition, etc). Forgive the self-promotion, but that is we did for episodic memory and for executive function in Obstructive Sleep Apnoea, if you want to see the sort of argument I am proposing above, applied in a review.

Finally, I cannot recommend highly enough the guidance on systematic reviewing written by the Centre for Reviews and Dissemination at the University of York, UK. The guide is free for download. Be warned, it's a big file, but makes for good reading. Good luck with this interesting project.

http://www.york.ac.uk/inst/crd/index_guidance.htm

Article Memory and Obstructive Sleep Apnea: A Meta-Analysis

Article Executive Dysfunction in OSA Before and After Treatment: A M...

Have you seen this older study

Hauri PJ

Sleep Disorders Center, Mayo Clinic, Rochester, MN, USA.

Acta Neurologica Belgica [1997, 97(2):113-117]

Neural pathways are constructed as the subject is awake longer that would not be constructed if the subject was asleep. These pathways enhance the senses.