Long-term Abstract Learning of Attentional Set

How does past experience influence visual search strategy (i.e., attentional set)? Recent reports have shown that, when given the option to use 1 of 2 attentional sets, observers persist with the set previously required in a training phase. Here, 2 related questions are addressed. First, does the training effect result only from perseveration with the currently active set or from long-term learning? Experiment 1 supported the latter alternative: When training and test were separated by up to 1 week, to prevent perseveration across the 2 sessions, the training effect was still obtained. Second, is the learning feature-specific (tuned to a precise set of colors) or more abstract? Experiments 2 and 3 supported the latter: When stimulus colors were switched between training and test to remove the possibility of feature-specific learning, the training effect again was obtained. These experiments indicate that attentional set is largely guided by long-term abstract learning.