Abstract
This study was conducted to examine the von Restorff effect and the influence of isolation on the recall of surrounding items. In the first experiment, twenty-seven undergraduates learned a homogeneous list and a list with one isolated item. Isolation was achieved by changing the color of the seventh item or by substituting an emotional item for a neutral one. Regardless of which method was used for achieving isolation, both the isolation effect and an inhibitive effect on items that followed the isolated item were obtained. The second experiment was designed to replicate the results of the first experiment by using pictorial stimuli that evoke emotion more strongly. The results from twenty-three undergraduates were similar to those of the first experiment. In addition to the isolative and the inhibitive effects, under the emotional condition, memory of the eighth stimulus was notably suppressed by the isolation of the seventh. These results suggest that the emotional tone of a stimulus is a crucial factor governing the degree to which spread to items adjacent to the isolated item is inhibited. A possible explanation is that the emotional shock state produced by an unexpected stimulus temporarily lowers the subject's ability to encode stimuli.
