What is an example of proactive interference?

Proactive interference occurs when old information interferes with the ability to learn or recall new information. The scenario where someone experiences difficulty recalling a new phone number after having memorized an old one perfectly illustrates this concept. The established memory of the old phone number disrupts the retrieval of the new number, leading to confusion or difficulty in recalling the more recent information.

The other scenarios provided do not exemplify proactive interference. Difficulty remembering the title of a recently read book could arise from various factors unrelated to old memories, such as a lack of attention or simply not having encoded the information effectively at the time of reading. Forgetting a friend's name after a long absence typically falls under the realm of forgetting without interference, as it is more about the decay of memory over time rather than an interaction between old and new information. Lastly, not being able to remember what happened yesterday suggests a more general memory lapse rather than interference from previous knowledge.