Health and Medicine
PUBLISHED
Hyperfamiliarity for faces (HFF) is a rare, disorienting condition characterized by feeling a strong sense of recognition for faces you’ve never actually seen before. Thanks to a new brain-imaging study – with a little help from the characters in HBO’s Game of Thrones – researchers have finally figured out what causes this confusing disorder.
To learn about the neurological underpinnings of HFF, the study authors scanned the brain of 49-year-old Nell, who developed the condition suddenly after a migraine. As a result, she often feels a pang of recognition when meeting complete strangers.
Using magnetic resonance imaging (MRI), the team observed Nell’s neural activity as she watched an episode of Game of Thrones – a show she’d never seen before (perhaps a blessing, given its notorious ending). Despite having no prior exposure to the characters, Nell claimed to recognize many of their faces.
Imaging results indicated that Nell’s visual system functioned normally during the experiment and had regular activity in key brain regions involved in recognizing faces, such as the fusiform face area. However, connectivity between these regions and the medial temporal lobe – which contains the hippocampus and other brain structures associated with memory – was found to be excessively strong.
The researchers therefore believe HFF is caused by an amplification of signals traveling between facial recognition regions and these memory structures, triggering a sense of familiarity for every face Nell sees.
“We were surprised to find that the visual face-selective regions were intact in HFF,” explained PhD student Kira Noad at the University of York, UK, in an email to IFLScience. “However, we found that connectivity between visual, face-processing brain regions and memory regions was enhanced in HFF. This finding makes sense, as it suggests that the brain recognizes that it sees a face, and the overly sensitive and exaggerated link to memory brain regions triggers the false sensation that a face is familiar.”
The study authors compared Nell’s brain activity to those of two groups of participants – one of which consisted of Game of Thrones fans, while the other was made up of first-time viewers. Strikingly, the activity in Nell’s hippocampus matched that of the show’s regular audience, despite the fact she had never previously tuned into an episode.
“Our findings provide an insight into the underlying neural correlates which may be valuable for future interventions,” says Noad. “For instance, we have shown that HFF is not a visual processing issue but may instead be better understood as an overly sensitive memory system issue. As such, future interventions may benefit from focusing on memory training, rather than visual.”
The study has been published in the journal Cortex.
