“…It has been shown that pre-exposure to CS alone or to US alone can interfere with the formation of CTA [for CS pre-exposure effect see 7, 22, 25, 44; for US pre-exposure effect see 2,3,4,6,8,12,14,16,18,21,22,31,41,42,43]. The pre-exposure to CS alone results in reduced associability between CS and US and the effect is known as latent inhibition.…”