Effects of negative air ions,noise, sex and age on maze learning in rats

An equal number of male and female rats of the King-Holtzman hybrid breed, divided into two age groups (group A₁ : 21–30 days old and group A₂ : 90–100 days old), were exposed to two levels of noise: N₀ = 30 db and N₁ = 90 db, (Ref. 0.0002µ bar), and three levels of negative air ions: I_O = no measurable ion concentration, I₁ = 7 × 10⁶ ions/cm³ and I₂ = 7 × 10⁷ ions/cm³. Time and error scores of 240 rats running a modified Lashley left-right maze with an escape-from-water motive served as criteria. A randomized complete blocks design with replications (2×3×2×2×10) was selected for treatment by analysis of variance. The results indicate that (a) the males show significantly lower error score in negatively ionized air; and (b) the females swim significantly faster than males under all investigated conditions with no apparent effect of noise or ions on their performance.