You’re watching Shadow and Bone on Netflix and General Kirigan struts across the screen. You immediately recognize the actor’s face; you’re 100 percent positive you’ve seen him in another show, but you have no idea who he actually is (spoiler: it’s Ben Barnes). Yet these moments are not unusual — how is it possible to recognize someone so instantly, and have no clue who they are or where you know them from?
You might spend hours of your weekend watching Barnes or any other actor onscreen for that matter, but ultimately one physical factor may make all the difference in how we recognize, and then remember the people we encounter in our everyday life.
What’s new — In a new study published Monday in the Journal of Neuroscience, researchers describe how our brains become familiar with faces, discovering that in-person — face-to-face — meetings matter more than you might think.
In the study, the researchers exposed participants to faces via different mediums — pictures, TV shows, and in-person — for different lengths of time. The results suggest we become familiar with faces we see in person more quickly than through any other means. What’s more, the researchers teased out some important distinctions between familiarization — recognizing a face — and identification–-being able to connect the face to the person.
The background — Gyula Kovács, one of the authors of the study, tells Inverse that we know networks running through many different brain areas are involved in how we process human faces, how we react to them, and how we ultimately memorize them. But Kovács says certain fundamental questions remain unsolved. Like:
- “How is [facial representation] created?”
- “How do the brain representations change as we ‘get to know someone?’”
This study homes in on the so-called “familiarity brain signal” to see how the brain’s response to a face changes over time as the person gets familiar with the face. To tease out the answer, Kovács and his colleagues measured participants’ brain activity using electroencephalography (EEG) both before and after they were exposed to different people’s faces in different settings — in images, videos, and in person.
What they did — The researchers conducted three experiments with three different groups of participants.
The first experiment tested “brief perceptual familiarization.” This was the lowest degree of exposure the participants had to the faces — in pictures only. In this part of the study, participants were shown pictures of four Hungarian actors, whom they briefly familiarized themselves with by doing a sorting task. Their brain activity was measured with EEG and then they were asked to match the face to the identity of the actor.
The second experiment tested how familiar we may become with faces through television or film. They showed the participants photographs of certain actors, including Keri Russell and Mathew Rhys, and then over the next two weeks, the participants watched a season of the television show The Americans. The researchers recorded each participants’ brain activity both before and after the binge-watch.
Finally, the third group of participants was exposed to in-person faces. Over three days, lab workers met with the participants for an hour. The researchers also took measurements of their brain activity before and after the participants had familiarized themselves with each lab worker’s face.
What they discovered — “We did not see any signal change after experiment one,” Kovács says. Experiments two and three were interesting. In these latter experiments, the researchers did find a signal change — a change in the brain’s electrical activity about 400 milliseconds after viewing the face.
Interestingly, the strength of the signal was strongest for face seen in person and less strong, but still there, after media exposure. This suggests that the brain learns faces fastest when it is introduced to them in person. Things become a little trickier to tease out when considering how familiarization — recognizing a face — relates to identification — recognizing and remembering the person attached to that face.
Why it matters — Kovács says it appears that familiarization and identification are not one and the same. This is important for understanding how we use in-person meetings and interactions to build strong, lasting relationships — whether they are with friends, co-workers, or family.
“The identity representation we could decipher from the activity in our experiments was not changed by learning, not even by the personal meetings,” he explains.
“We expected that after the week of being exposed to our lab members, the participant will develop some kind of ‘person-specific’ representation.”
If that was the case, identity representation would have changed as a result of the familiarization training. But it didn’t.
“The brief, one-week long series of personal meetings were not enough yet to create the representation we looked for,” he adds.
Think of it this way: You bump into someone in a store and you are 100 percent sure that you know them from somewhere but have absolutely no idea what their name is or where you know them from. At least from a neuroscientific standpoint, it’s completely typical of your brain to do that.
“We can say safely that [familiarization and identity representation] develop differently in time,” Kovács says.
“While familiarity information is created reliably by the media and personal training of our study, they are still not enough to create the genuine ‘identity’ representation of a person,” he says.
“For that, we might need longer-lasting and more intensive training, preferably in-person real life.”
What’s next — The results have left Kovács more questions to explore in future research, he says. For one: “Why do the media and personal familiarization results differ?”
“Think about the frequent Zoom meetings we have now during the pandemic. Do we ‘know’ someone we only met virtually the same way as our friends?”
“What is the role of personal interactions? Watching films, videos, or interacting in real-time with the person on the screen (by Zoom) is surely different for learning people in real life. But how is it reflected in the brain?”
Abstract: The successful recognition of familiar persons is critical for social interactions. Despite extensive research on the neural representations of familiar faces, we know little about how such representations unfold as someone becomes familiar. In three EEG experiments on human participants of both sexes, we elucidated how representations of face familiarity and identity emerge from different qualities of familiarization: brief perceptual exposure (Experiment 1), extensive media familiarization (Experiment 2) and real-life personal familiarization (Experiment 3). Time-resolved representational similarity analysis revealed that familiarization quality has a profound impact on representations of face familiarity: they were strongly visible after personal familiarization, weaker after media familiarization, and absent after perceptual familiarization. Across all experiments, we found no enhancement of face identity representation, suggesting that familiarity and identity representations emerge independently during face familiarization. Our results emphasize the importance of extensive, real-life familiarization for the emergence of robust face familiarity representations, constraining models of face perception and recognition memory.