"We have all had the experience of watching a movie trailer and having the overwhelming feeling that we can see much more than we could possibly report later.” said Aude Oliva, associate professor of brain and cognitive sciences and senior author of a paper which will appear in the Proceedings of the National Academy of Sciences the week of September 8. In scientific literature, it is easy to find support for a demonstration of memory's failures which has convinced many scientists that the human memory does not store the details of our experiences. However, the work of MIT cognitive neuroscientists may overturn this widespread belief because, as we can read, "visual long-term memory capacity is much higher than previously believed and shown”. They have shown that given the right setting, the human brain can record an amazing amount of information. In the study, the results of which could have widespread implications, people viewed thousands of objects over five hours. Remarkably, afterwards they were able to remember each object in great detail. Does it mean we have the capacity to remember everything and be total “recallers” ? (using the idea present in Paul Verhoeven’s movie entitled “Total recall”)
Oliva and her students showed the subjects nearly 3,000 images, one at a time, for three seconds each. To maintain attention and to probe online memory capacity, participants performed a repeat-detection task during the 10 study blocks. Repeated images were inserted into the stream, and participants were told to respond by using the spacebar anytime that an image was repeated throughout the entire study period. In tests, the same day, they were shown pairs of images and asked to select (also pressing space bar) the exact image they had seen earlier (force-choice task). Subjects were tested with three types of pairing: two totally different objects; an object and a different example of the same type of an 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, the subjects' recall rates in the three types of memory tests were respectively 92 percent, 88 percent and 87 percent.
Previous studies had never found that we could hold so many details in our memory, partially 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 details, which were part of this study. Second, it helps if the objects viewed are familiar. The images used in this study were all everyday items such as remote controls, dollar bills and loaves of bread. The results were likely to be different if subjects were asked to remember details of abstract artworks
Implications of this study in the field of neuromarketing and/or human decision-making could have been far beyond obviousness. Most models of advertising assume that our memory is a gate to measuring its efficacy. But the question is: what kind of memory and how to measure its influence? This study confirms that crucial is not what you can report but actually what your “brain” remembers and what can have impact on your behaviour (of course provided you have enough time to encode memory trace what is quite difficult in a common situation). In fact, it doesn’t matter whether we call “massive memory” implicit or explicit but it is important that it’s powerful enough to guide our decisions. But you will know it only then you know how to measure it. Asking what someone could remember often delivers useless or at least imprecise information, but more elaborated methodologies such as forced-choice tasks, especially enriched with measuring of RTs (what could add a dimension of measuring certainty in this case) and real behaviours (e.g shelf-test in market research) are in many ways “state of the art” solutions.
Our memory system still seems mysterious in many ways but this new finding doesn’t mean a return to older models describing functioning of memory in terms of the conscious “recall”. Just the opposite. Rather now we can try to connect all we have known about memory so far with a new portion of scientific results. And as a result we could assume that humans are gathering knowledge in their “memory brain” not only to express it by verbal means later but primarily to actively rely on it in many everyday decisions, probably out of conscious deliberation. In other words, we have massive (visual) memory capabilities not to form propositional knowledge and share it with others but to increase reliability of behavioural outcomes in natural settings. And this is the answer why our memory can seem such powerful in these experiments. The choice itself matters, not the memory files supporting it.
So, should you call me a total “recaller” ? I don’t think it makes sense at all.
