If you are asking about at what time is an event in spanish, you must use the preposition .

How did loftus interpret false memories? a. because of their desire to whoever is asking them about their memories people will often go along with what they want to hear b. eyewitness memories becomes faulty when we make errors in identifying the source of information we have stored in long term memory c. we accept subsequent misinformation as being correct, and this information becomes part of our memory for the original event d. when we retrieve a memory for a particular event from long-term memory, we also retrieve information from other sources relevant to the event