Which aspect of memory is primarily affected by rehearsal of the first items in a sequence?

Rehearsal of the first items in a sequence primarily impacts long-term memory due to a phenomenon known as the "primacy effect." This concept suggests that items presented at the beginning of a list are more likely to be transferred into long-term memory as they are often rehearsed more frequently and given greater attention. When we repeat or mentally rehearse these initial items, they are encoded more effectively and are more readily retrievable later on.

In contrast, working memory is involved in temporarily holding and manipulating information, and short-term memory refers to the capacity for holding a limited amount of information over brief periods. While rehearsal can influence these forms of memory, its strongest effect is seen in the establishment and persistence of memories in long-term storage. Impromptu memory is not a scientifically recognized category in memory studies, so it does not apply to the context of this question. Thus, long-term memory is the best fit for understanding the impact of rehearsing initial items in a sequence.