At the Stanford University Virtual Human Interaction Lab, 6-year-old Sam listened intently to an experimenter describing a fictitious scenario where Sam was swimming with two friendly orca whales in beautiful blue water. When Sam was questioned if he could recall ever swimming with the orca whales in real life, he vehemently shook his head.
Later on, Sam’s classmate Adam came to the lab. Adam donned a virtual reality helmet that immersed him into a world completely different from the lab’s physical surroundings. Within a few seconds, Adam could see himself underwater frolicking with two orca whales. The three-dimensional virtual version of Adam was a near mirror reflection of his physical body — with short brown hair, alert brown eyes, and the corners of his lips turning up in a natural smile. He appeared to really enjoy swimming with the orca whales.
After a few minutes the underwater world faded, and the experimenter helped the boy lift the virtual reality helmet off of his head. The experimenter asked Adam, “Do you remember swimming with these whales in real life?” Unlike Sam, Adam wasn’t so quick to respond, and he bit his lip a little as a concentrated look came across his face. “I think … yes, I think I remember now,” he replied.
Human memory is complex. Humans encode, store, and retrieve bits of information constantly; and while these processes are frequently accurate, the human mind is fallible. Human memory errors range from failure to retrieve stored events to what scientists call false memories — “remembering” events that did not occur, as in Adam’s case. Most of such memory errors do not garner national attention, but false memories of sexual abuse — supposedly planted and elicited by therapists — became the subject of several prominent lawsuits in the 1990s. These lawsuits drew the attention of the general public and many scholars and motivated research on false memories.
In order to understand how Adam developed a false memory of swimming with the orca whales, we must first be familiar with how the human brain stores and retrieves bits of information and identify where this process is vulnerable to error. Numerous studies on false memory creation have revealed that repeated interviewing, leading questions, and biased interviewers, along with other causes, can lead to memory errors in everyone, and with children in particular.
Memory: How It Works And Why It Errs
Memories come from a variety of sources, such as television, imagination, books, and first-hand physical experiences, but according to the “source monitoring framework” developed by Marcia Johnson, a professor at Yale University, memories are rarely stored with tags that identify their sources. This means that each time a memory is retrieved, the brain attempts to determine the source of the memory. During this rapid and mostly automatic source-monitoring process, memories are evaluated and attributed to particular sources.
Each type of source produces memories with unique characteristics. For example, physical-world memories — memories of events that actually happened to the rememberer — are extremely rich in perceptual detail. Memories developed from a book, however, usually do not contain as much detail. One of the indicators the human brain uses to determine a memory’s source is the amount of detail stored in a memory.
Another indicator of a memory’s source is the amount of cognitive effort the brain uses to organize and store the memory. Little cognitive effort is needed to store and organize the memory details for a physical-world event. On the other hand, it takes substantially more cognitive effort to organize and store the details of an event that was merely read about in a newspaper. The brain is able to differentiate memories that require high effort to organize and store from memories that require low effort, and the brain uses this information to draw useful conclusions about the sources of our memories.
The problem is that today’s digital media, such as video games and websites, as well as the virtual reality helmet that Adam donned, are so rich with detail — from three-dimensional graphics and personalized avatars to high-quality sound and more — that it is easy for the human brain to organize and store memories derived from detail-rich experiences with digital media. Thus, it becomes difficult for the brain to distinguish between memories of physical-world experiences and memories of experiences with digital media — both of which tend to be rich in detail and relatively easy to organize and store. In a study published in the journal Media Psychology, we discovered that source-monitoring errors occur in direct proportion to media richness.
