Human memory is not reliable even in the short term
When people have firm expectations about what the world should be like, their memories may start to fade even within a few seconds (Getty Images)
Memory parameters are determined by what we expect to see from the moment the first trace of it appears
People's memories may consist of false events, and this happens most of the time after a few moments of their occurrence, so they redraw their details to match their expectations. That's what a new study reveals, which sheds more light on such illusions in short-term memory .
In this context, previous studies have shown that people's perception of their surroundings is determined by their expectations, and this leads to the emergence of illusions.
Research has shown that people's long-term memories may be formed in a way that matches their expectations, sometimes showing false memories . However, it is generally accepted that short-term, perceptual memories of what happened a second or two ago provide an accurate picture of the environment, according to findings by scientists, including those from the University of Amsterdam in the Netherlands.
Previous studies have shown that people's perception of their surroundings can be shaped by their expectations, which can lead to delusions.
The research also revealed that within a time scale as short as one to two seconds, people could reliably describe what actually happened or, alternatively, reliably give false details of what they expected to happen at the time.
Scientists emphasized that even within such short time frames, it may be impossible to fully trust human memory, due to illusions that pervade short-term memory.
The study indicated that when people have firm expectations about what the world should be like, their memories may start to fade even within a few seconds, so they work to fill the void created by the fading information with their expectations.
In previous research, participants were briefly shown an image of an inverted letter, and said they saw it in the right direction, when the illusion [issue] was brought to light again, and it was suspected that the error was due to the participants not seeing the shape of the letter well.
Subsequently, the scientists conducted four experiments to test this phenomenon in the context of the new study.
During the first experiment, participants were given a test to ensure that they could complete intuitive visual memory tasks, and were then shown to draw a circle with six to eight letters, including one or two backwards letters.
In order to divert the participants' attention, they were then shown a second circle that contained symbols that they had to ignore.
In the next stage, the participants were asked to choose a specific target shape from a list of letter choices located in a specific place in the first circle, and then they were asked to indicate their confidence in the choice they had made.
The researchers discovered that the participants reported with a lot of confidence that they had seen the actual counterpart of the letter that was reversed.
The scientists justified the miscalculation by saying that it resulted from the participants' previous knowledge of the alphabet, which contributed to determining their expectations, and was not caused by any similarity in the shapes of the letters.
"These memory illusions appear to result from knowledge of the world, rather than from visual analogies," the researchers wrote in the study.
Other experiments, the following, showed that fictitious memories in which the person thought the reflected letters were original outweighed the fictitious memories in which the person thought the original letters were reversed.
In this context, the researchers pointed out, "We will see, therefore, if we combine the results, that knowledge of the world is able to map the features of memory, even if the memories have just arisen."
"Taken together, the results show that global knowledge can shape memory even when memories are just forming," the researchers noted.
These findings revealed that phantom memories may emerge even if the visual stimulus is out of view for very short periods of time, indicating that even if people's memories are really recent, they are likely to be phantom.
The researchers concluded by saying, "This indicates that internal priorities play a vital role not only during the perceptual stage, but also during the remembering stage."
Source: websites