Individuals with insomnia consistently report difficulties pertaining to their cognitive functioning (e.g., memory, concentration). However, objective measurements of their performance on neuropsychological tests have produced inconsistent findings. Recently, Fortier-Brochu E conducted a meta-analysis to provide a quantitative summary of evidence regarding the magnitude of differences between individuals with primary insomnia and normal sleepers on a broad range of neuropsychological measures. They found significant impairments (p<0.05) of small to moderate magnitude were found in individuals with insomnia for tasks assessing episodic memory (ES=-0.51), problem solving (ES=-0.42), manipulation in working memory (ES=-0.42), and retention in working memory (ES=-0.22). No significant group differences were observed for tasks assessing general cognitive function, perceptual and psychomotor processes, procedural learning, verbal functions, different dimensions of attention (alertness, complex reaction time, speed of information processing, selective attention, sustained attention/vigilance) and some aspects of executive functioning (verbal fluency, cognitive flexibility). Therefore, they concluded that individuals with insomnia exhibit performance impairments for several cognitive functions, including working memory, episodic memory and some aspects of executive functioning.