Stanley Coren put some numbers on the effect of sleep deprivation upon IQ test scores.
There’s a more detailed meta-analysis of multiple studies, splitting it by types of mental attribute, here:
A Meta-Analysis of the Impact of Short-Term Sleep Deprivation on Cognitive Variables, by Lim and Dinges
Stanley Coren put some numbers on the effect of sleep deprivation upon IQ test scores.
There’s a more detailed meta-analysis of multiple studies, splitting it by types of mental attribute, here:
A Meta-Analysis of the Impact of Short-Term Sleep Deprivation on Cognitive Variables, by Lim and Dinges