“…When a neutral stimulus is repeatedly presented without consequences it results in one or more of a range of processes, including a progressive decrease of orienting responses (Sokolov, 1963;Turpin, 1983), the gradual reduction of attentional responses elicited by the stimulus (Lubow, 1989), the reduction of stimulus associability (e.g., Mackintosh, 1975;Pearce & Hall, 1980), the development of an association between the context and the stimulus (e.g., Wagner, 1978), and/or an association between the stimulus and the absence of following consequences (e.g., Bouton, 1993;Hall & Rodriguez, 2010). Some of the aforementioned processes, or a combination of them, determines that, when the preexposed stimulus is subsequently presented again and is followed by an Unconditioned Stimulus (US), the resulting Conditioned Response (CR) is weaker as compared to that elicited by a stimulus that has not been preexposed before conditioning.…”