Final answer:
Decreasing the interval time between word presentations decreases memory performance for later items due to proactive interference.
Step-by-step explanation:
Decreasing the interval time between the presentation of word items will lead to a decrease in memory performance for words later in the list. This effect relates to interference in short-term memory, specifically proactive interference, where earlier information hinders the recall of newly learned information. Studies have shown that when the time interval between information presentation decreases, there is not enough time for the earlier items to be processed effectively, making it difficult to remember subsequent items. This is due to the short-term memory's limited capacity and the interference of earlier items with the encoding of newer ones into long-term memory.