Final answer:
The misinformation effect occurs when misleading post-event information alters a person's memory of an event, highlighting the impact of suggestibility on memory recall.
Step-by-step explanation:
The occurrence when participants' recall of an event they witnessed is altered by introducing misleading post-event information is known as the misinformation effect. This effect demonstrates how suggestibility can lead to the creation of false memories. Cognitive psychologist Elizabeth Loftus has conducted significant research in this area, demonstrating through experiments that the wording of a question can alter an eyewitness's memory. For example, when participants were asked to estimate the speed of cars in an accident using differently loaded words (e.g., smashed vs. bumped), their speed estimates varied accordingly. This is a clear illustration of how suggestibility, through the use of leading questions or other misleading information, can significantly alter and distort an individual's memories of an event.