Our memory for the who, what and why of a situation appears to fade over time, but we may be better at remembering where it took place. Understanding how memories can change could have implications for how we judge eyewitness testimonies in criminal cases.
To better understand how memories change, and her colleagues at the University of Chicago carried out two experiments. In the first, 1609 people were shown images of six scenes 鈥� a bedroom, kitchen, living room, amusement park, garden and public park 鈥� for varying lengths of time, from 100 milliseconds to 10 seconds.
Immediately after seeing the images, they were asked to recreate them, in as much detail as possible, using Amazon Mechanical Turk, an online set-up that allows people to draw using their computer鈥檚 mouse or trackpad.
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In the second experiment, 942 people were shown the same scenes, all for 10 seconds. Some were asked to draw these immediately afterwards, while others did so 5 minutes, 1 hour, one day, two days or one to two weeks later.
The researchers assessed how many of the objects, such as a bed or tree, within the scenes the participants included in their drawings. Perhaps unsurprisingly, they found that object recall decreased the less amount of time the participants looked at the images and the longer they had to wait to do their drawings.
About one-fifth of those who waited around two weeks drew at least one object that didn鈥檛 feature in the original scene, with three-quarters of these drawings containing more than one false object.
But the team was surprised to find that while the participants didn鈥檛 correctly remember all the objects within the scenes, of those that they did remember, they could correctly locate them within the images. , one of the researchers, says 鈥渢here might just be something special about spatial memory鈥� that makes it different from how we remember other things.
This is important to understand for situations when accurate recall is crucial, such as during eyewitness testimonies, says Megla. Perhaps details regarding the location of a person or object given by an eyewitness are more accurate than those about appearance, she says.
However, it is unclear whether our ability to recall objects is based on pre-existing patterns of thinking, says Megla. For example, someone may recall a nightstand as being next to a bed, but it is unclear if that is because they remember that detail from the image or if they are assuming that is where a nightstand would logically be.
at the University of Edinburgh in the UK says that since the participants were sketching on an online platform, 鈥渟ome might have omitted objects from their drawing simply because they found drawing with a mouse awkward and tiring鈥�.
Next, Megla hopes to 鈥渟cramble鈥� the scenes the participants saw by placing objects in non-obvious places to ensure they rely less on pre-existing thinking patterns.
bioRxiv
