Answer:
Retroactive interference
Explanation:
There are two types of interference: proactive and retroactive.
There is proactive interference when a person is not able to learn a new task because an old task has already been learnt. Old memories interfere with the new things a person is learning right now.
There is retroactive interference when a person forgets what he/she has learnt before as a result of learning a new task/thing. Later acquisition of knowledge interferes with previous learning. When the memories are similar, proactive and retroactive interferences are more likely to occur. In the case at issue, Kieran has been learning similar subjects (languages), so it is more common to experience this type of interference.
