Berlyne, D. E., & Normore, L. F. (1972). Effects of prior uncertainty on incidental free recall. Journal of Experimental Psychology, 96(1), 43-48.
http://dx.doi.org/10.1037/h0033480
Found that subjective uncertainty, induced in 53 male and 55 female undergraduates through blurred pictures, facilitated both immediate and delayed incidental recall, but not intentional recall, of objects portrayed in subsequent clear pictures. This finding corroborates those of previous experiments, in which the induction of uncertainty through prior guessing facilitated incidental paired-associate learning of words. Further experiments with 53 male and 47 female Ss show the effect to be absent when blurred pictures were dissociated from uncertainty or when clear pictures did not relieve uncertainty. The effect occurred, whether or not S knew, on seeing a blurred picture, that the corresponding clear picture would follow. Explanations in terms of reinforcement through reduction of epistemic curiosity and in terms of attention are discussed. (16 ref.) (PsycINFO Database Record (c) 2016 APA, all rights reserved)