After performing a simple cognitive memory test on a bunch of subjects, MIT researchers believe they showed that human memory capacity is much larger than was previously thought.
Oliva [Aude Oliva, associate professor of brain and cognitive sciences] and her students showed subjects nearly 3,000 images, one at a time, for three seconds each. In tests the same day, they were shown pairs of images and asked to select the exact image they had seen earlier.
Subjects were tested with three types of pairings: two totally different objects; an object and a different example of the same type of object (e.g. two different remote controls); and an object and a slightly altered version (e.g. a cup that is either full or half-full).
Against all expectations, subjects’ recall rates on the three types of memory tests were 92 percent, 88 percent and 87 percent, respectively. “To give just one example, this means that after having seen thousands of objects, subjects didn’t just remember which cabinet they had seen, but also that the cabinet door was slightly open,” Brady said.
While a previous study from the 1970s showed that people could remember many individual images, scientists assumed that people could only remember abstract descriptions of the images (for example, “a photo of a wedding”), but not details about each one.
The new results suggest that visual capacity is several orders of magnitude higher than the older study implied. “If you encode a lot of detail for each object, you need a lot more space,” Alvarez said.
Traditional models of vision theorize that details necessarily slip away as visual input travels from the eyes to higher processing centers in the brain. The new results may prompt neuroscientists to revise those models to account for how people remembered so many details, Konkle said.
Previous studies had never found that we could hold so many details in memory, in part because they didn’t look for it.
However, the researchers believe that multiple factors play a critical role in how well people remember details. For instance, it makes a huge difference if people are motivated to pay attention to detail, which they were in this study.