During a party, as you're chatting away with other guests, you suddenly turn around at the sound of your name. This is an all-to- familiar way of capturing your attention. Indeed, we are primarily interested in stimuli that relate to us personally, something known as the "self-referential bias." Based on this observation, researchers wanted to test if a similar phenomenon could be seen in the brain. It was a chance to discover whether our brain makes us naturally self-centered…

Tobias Egner, an Associate Professor in the Department of Neuroscience at Duke University (United States) and one of the study’s co-authors, says that we tend to prefer external stimuli that are somehow related to us. But according to Egner, the real question is whether or not this prioritization and hierarchy is automatic. “If so, that could really bias how you make decisions.” He and his colleagues at Southwest University (China) and the University of Bath (England) wanted to know if the self-referential bias also applied to internal representations, like those stored in working memory.

Sometimes called short-term memory, working memory allows us to cognitively process temporarily stored elements. It is solicited in processes that involve reasoning, such as reading or calculating. According to Egner: “We use working memory to make complex decisions where we have to weigh different pieces of information and keep them in mind. If you always put self-related information first, then this bias could drive your decisions (…) when you evaluate different options.” To test the self-referential bias in working memory, the research team tested 102 participants on a program they created.

First, the scientists taught the subjects to associate social labels (“friend,” “stranger,” “self”) with colors (blue, green, and purple). The “game” was very simple: two dots of different colors flashed briefly on a screen. This was followed by a five-second pause during which the participants had to remember the color and position of the dots. A black dot then appeared on the screen. The participants were asked to indicate whether the black dot flashed in the same place as one of the colored dots, and, if so, the color (label) of the corresponding dot. In this first experiment, the participants correctly identified the “self” dots much faster than the “friend” or “stranger” dots. This indicates that the participants’ working memory was significantly more concentrated on the “self” labeled dots.

Next, in an experimental variant, the scientists modified the computer program so that the color associated with “me” appeared half as often as the “friend” and “stranger” colors. The idea was to see if people would still give priority to the “self,” even if it hurt their performance. But the participants were still faster with the “self" color.

The protocol’s associations between color, social label, and location were clearly totally arbitrary, and there was absolutely no reason to favor one color over another. But in each experiment, the subjects always favored the color that was associated with them. The authors believe this suggests there is an automatic prioritization of self-referential elements in working memory, which can form the basis of self-centered biases in decision-making.