The Von Restorff effect, or isolation effect, indicates that when multiple similar stimuli are presented, the one that stands out is more likely to be remembered. This phenomenon was studied by Hedwig von Restorff, who found that an outlier item in a list significantly enhances recall due to its distinctiveness. Variations in size, shape, color, and other features contribute to this memory enhancement by making the item more noticeable.
For instance, if someone sees a shopping list where one item is highlighted in bright green among regular black text, they are more likely to remember the highlighted item than the others. Similarly, in a list of words that includes 'chipmunk' among furniture items, 'chipmunk' will likely be remembered best due to its uniqueness.
To mitigate the Von Restorff effect, increase attention to all items by ensuring they are presented in a consistent format and highlighting the context in which each item is important, rather than focusing solely on distinctiveness.