10 Ways Your Memory Is Completely Inaccurate

A wide variety of factors can influence how well you remember, or don't remember, certain events. These are called memory biases. Memory biases can also affect how quickly you're able to recall something, while certain types of biases may actually alter some of your memories. Here are a few of the more common memory biases [source: Cohen]:

Do you remember exactly where you were and what you were doing when you heard the news that President John F. Kennedy was shot? Or when the space shuttle Challenger exploded? Or when the 9/11 terrorist attacks occurred? If so, that's a flashbulb memory. When something traumatic occurs, our brains can sometimes create a very sharp memory of the event that includes minute details, much like a photograph. This is because such events are both personal — we experience them either firsthand or via TV — and public — everyone around us does, too, and subsequently talks about them [source: Law].

The concept of flashbulb memories was first proposed by two psychologists in 1977, and it's still controversial. The naysayers argue that studies show people's flashbulb memories do deteriorate over time, and sometimes significantly. But flashbulb backers say those studies don't compare the amount a flashbulb memory deteriorates over time compared to a regular one. Other studies show flashbulb memories really aren't that sharp over time, but we perceive them as quite vivid, likely because of their strong emotional component. What does seem accurate, though, is that the closer and more emotionally invested you are to a traumatic event, the better your recollection of it [source: Law].

In the 1990s and beyond, a raft of cases came before American courts concerning implanted memories. A typical case involved a female who went to see a psychotherapist for an issue such as depression. During the course of treatment, she suddenly recalled being sexually abused by a trusted friend or family member as a child. The conclusion was that she had repressed this traumatic memory over the years, and over time it caused her depression or other mental health issue.

Many researchers have conducted studies showing false memories can be implanted into someone's mind by asking suggestive, leading questions. For example, "You're depressed but don't know why. Do you remember your father ever touching you inappropriately as a child?" Hypnosis, guided imagery, dream interpretation and feeding a subject misinformation after an event can also implant a false memory into someone's mind [sources: Hayasaki, Vitelli].

Dr. Elizabeth Loftus, a cognitive psychologist and expert on human memory has conducted hundreds of experiments throughout her career that show it's pretty easy to change someone's memory about an event. She told attendees at a conference of the Committee of Skeptical Inquiry that it's also quite easy to create a false memory in someone's mind. For example, in one study, researchers were able to convince 25 percent of subjects they'd been lost in a shopping mall as children. She added that even traumatic false memories — nearly drowning or, yes, being sexually assaulted — can be implanted in the minds of some [source: Vitelli].

The subject of implanted false memories is a hotly debated issue, namely its relation to recovered memory therapy, one of the more divisive issues in the mental health arena. The issue is serious and contested in part because it can have such dire consequences. The case typically cited is that of Gary Ramona, whose daughter accused him of years of sexual assault after going through psychotherapy and receiving the drug sodium amytal. Ramona vehemently denied the accusations and sued the therapist for implanting false memories in his daughter. Although he won the case, his wife divorced him and he remains estranged from all of his children [sources: LaGanga, Vitelli].

Much like implanting memories, suggestibility involves false memories that make their way into your mind even though a particular event that you recall never occurred. The difference is that implanted memories tend to occur after a more active process (someone asking leading questions), while false memories that form due to suggestibility are often unintended.

Slate magazine showed one way in which suggestibility works through an informal study in 2010. The publication altered or fabricated five photos based on recent political events. (Doctoring photos to test memory has been used by researchers for years.) Study participants were shown three real photos plus a doctored one. They were told all four photos depicted real events, and were asked if they remembered these events [source: Saletan].

While participants remembered the real events much more readily than the fake ones, plenty of folks were positive they remembered the fake events depicted in the doctored photos. For example, 26 percent of participants who saw a doctored photo of President Obama shaking hands with Iranian President Mahmoud Ahmadinejad reported previously seeing this photo or event. And a full 42 percent were positive they remembered Vice President Dick Cheney calling out Sen. John Edwards during a presidential debate after Edwards brought up Cheney's lesbian daughter, a scene created in one of the doctored photos. Both events, as noted, never occurred [source: Saletan].

In analyzing the results, the magazine also discovered people are more likely to falsely recall events that match their political beliefs. Those who weren't fond of President Obama, for example, were more likely to "remember" his handshake with Ahmadinejad [source: Vitelli].

The theory of repeated exposure creating false memories is linked with suggestibility and implanted memories. As you read earlier, if someone asks you leading questions, you might "remember" an event that never occurred. Similarly, if someone tells you President Obama is a Muslim, and you're a conservative who doesn't care for him, you may falsely remember reading an article about the president attending services in a mosque. Repeated exposure takes these concepts a step further, saying that the more times you're fed misinformation or leading questions, the more likely you are to swear a particular memory is true.

In one study conducted by researchers at Kent State University, subjects were shown a video of a burglary, then asked questions with misleading suggestions. Some of these were repeated. Later, the subjects were asked how they knew certain pieces of information about the burglary. The subjects were more likely to say they learned this information from the video, even if it wasn't in there, if the information was suggested to them more than once in the follow-up questioning. Even a week later, many subjects were still positive they had learned the repeatedly-suggested information from the video [source: Zaragoza and Mitchell].

It's the strangest thing. You've never traveled to Paris before, yet now that you're here, standing on a bridge spanning the Seine River, you distinctly remember being in this spot before. You can recall features of the bridge, and the curve of the river. You're likely going through déjà vu, a fleeting illusion that you've previously experienced something, when in reality you have not.

Déjà vu occurs because our minds are good at remembering objects, but not the placement or configuration of them. For example, it's relatively easy to notice that your colleague is wearing a pretty blue dress that your sister also owns. But let's say someone asks you to describe how the stalls are laid out at your local farmers' market. You might not be able to recollect that. Yet if you go to the art fair in a neighboring town and the vendors' booths are laid out in a similar configuration to those in your local farmers' market, you might get a feeling of familiarity. And if they're laid out in nearly the exact same fashion, you might feel that you've been to this art fair before. That's déjà vu [source: Markman].

In a way, you could say the concept of memory rewriting is the overarching reason our memories are inaccurate. A study published in a 2014 edition of the Journal of Neuroscience, was the first to show that our brains constantly rewrite our memories to some extent, inserting useful, current information. It's a survival mechanism that ensures we're dealing with what's important today, not in the past, so that we can make good decisions. In the study, 17 men and women looked at objects with backgrounds (say, of farmland) on a computer screen. Then they had to place the object in the original location but on a new background screen. The participants always put the object in the wrong spot. Finally, they were shown the object in three locations — where it was originally, where it had been placed the second time, and a brand-new location — and asked to pick the correct spot for it. The researchers found that people always chose the second location, rather than the first [source: Paul].

"This shows their original memory of the location has changed to reflect the location they recalled on the new background screen. Their memory has updated the information by inserting the new information into the old memory," Donna Jo Bridge, the lead study author, said in a news release.

So, if you're now happily married, you may recall being intensely attracted to your spouse on that first date. But if you're pondering a divorce, you may instead remember not liking him very much. People suffering from depression or post-traumatic stress disorder sometimes aren't able to rewrite old memories with new information. Their old memories are stuck, unable to adapt to the present. They aren't able to see that things can be different, which can cause much angst [sources: Paul, Weintraub].

You've probably called a person by the wrong name. Misattributions are a pretty common way in which our memories are faulty. And they can take many forms. One of the more common is misattributing the source of an event. Your friend tells you about a tornado hitting a nearby community, and later that day you tell your husband you learned of the event from an online source.

Another form of misattribution involves matching the wrong face to a particular event. So you may be positive your sister was shopping with you the day your handbag was snatched, when you were really with your mother. Sometimes, you may even imagine an event, then later believe it actually occurred — misattributing fantasy to reality.

In one memory study, some people were asked to imagine performing an action, while others were asked to actually perform it. Later, the performing and imagining were repeated. Finally, the subjects were asked whether they had performed the action or merely imagined it. Many who had only imagined it were sure they had performed it. Interestingly, or perhaps shockingly, misattributing memories in these ways are considered to be a daily occurrence for most of us [source: PsyBlog].

Our minds are constantly taking in information, then filtering it through our various experiences and biases so that it makes sense in our lives. That's why several eyewitnesses to the same event often report different stories. You may see a two-car collision and recall how the blue car broadsided the red car after blowing through a stop sign, because that once happened to you, while someone else may emphasize the fact that the driver of the red car was yakking on her phone, because that's a pet peeve of hers. One memory researcher explained it this way: We all have personal narratives that are formed by our beliefs and values. Our minds take our memories and create explanations for what we've seen or heard based on those beliefs and values [source: Hayasaki].

Filtering may be behind some of the numerous inconsistencies in eyewitness reports of crimes, such as the 2014 tragedy in Ferguson, Missouri. In that incident, a white police officer (Darren Wilson) shot and killed an unarmed, 18-year-old black man (Michael Brown). Some witnesses said Wilson charged at Brown first. Others said Brown never moved toward Wilson. Some witnesses claimed Brown put his hands up in the air but Wilson shot him anyway; others said Brown never put his hands up or only put them briefly [source: New York Times].

As you've learned, our brains keep tinkering with our memories, adding information and distorting aspects. More ominously, some of our memories may become so distorted over time, they end up totally false. So in addition to rewriting the memory when you recall it (as we read about earlier), every time you think of the memory, you're actually recalling the memory of the last time you thought about the memory, rather than the event as it happened weeks or months or years ago [source: Paul]. And you won't realize this is happening.

This isn't a comforting thought, especially if you love recalling the childhood memory of your kindly old neighbor, who always gave you and your sister apple slices and candy when you stopped over to visit. On the other hand, maybe she never did this at all. In fact, maybe she always ignored both of you, or even chased you away.

Perhaps the lesson to be learned about our memories, aside from the fact that they're fraught with inaccuracies, is simply to enjoy the good ones and believe them to be real, while telling ourselves the bad ones are all modified falsehoods.