Emma attends a friend's party. in the party, despite talking at length with lots of people, she only remembers the names of the last few people she met. in this scenario, emma is demonstrating the:

Emma is demonstrating the recency effect.

The recency effect is one of the two effects embodied in the so-called serial position effect. This effect describes how people tend to remember better the first (primacy effect) and the last elements in a series (recency effect), when this person is asked to recall the list.

In this case, Emma only remembers the last people she met out of a long sucession of different people along the party. Therefore, this is an example of the recency effect.