The largest effect was seen in experiments using the shuttle box task detected the highest (2.34 SMD, 95% CI, 1.7 to 2.89) and the smallest in those using the radial arm maze task (0.19 SMD, 95% CI, -0.73 to 1.11: χ2 for difference = 339.48, Τ2 = 1.12, I2 = 77.3%, d.f. = 77, p<0.0005; Fig 3D). We found no significant effect on the impairment in NBS of the model duration, route of administration, animal gender or rodent type (mouse versus rat).