This research investigated the effects of positive and negative air ionization on the early acquisition of a Sidman (1953) avoidance response. The subjects were 20 male albino rats of the Sprague-Dawley strain. They were randomly assigned to ionization conditions and given 4 2-hr. acquisition sessions. The temporal parameters of the task were a response-shock interval of 20 sec. and a shock-shock interval of 5 sec. Shocks were delivered as 1-ma. pulses of 1 sec. duration. The results indicated that at the end of 4 2-hr. sessions the avoidance performance of rats trained in the presence of negative air ions was superior to that of rats trained in the presence of positive air ions.
The determination of correction factors for free-air ionization chamber calculation using monte carlo method