Forest plot of effect sizes of α7 nicotinic agonists on the novel object recognition task and water maze tasks in rodent models of cognitive impairment. Meta-analysis demonstrated a significant effect in the novel object recognition task (A) compared to vehicle (Effect size (ES) = −0.73, 95% CI = −1.00 to −0.45, p < 0.001), and a significant effect in the water maze task (B) compared to vehicle (ES = − 1.18, 95% CI = −1.69 to −0.66, p < 0.001). Note: negative effect size favors drug treatment.