PT  - JOURNAL ARTICLE
AU  - Hamid Karimi-Rouzbahani
AU  - Farzad Remezani
AU  - Alexandra Woolgar
AU  - Anina Rich
AU  - Masoud Ghodrati
TI  - Perceptual difficulty modulates the direction of information flow in familiar face recognition
AID  - 10.1101/2020.08.10.245241
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.08.10.245241
4099  - http://biorxiv.org/content/early/2020/08/11/2020.08.10.245241.1.short
4100  - http://biorxiv.org/content/early/2020/08/11/2020.08.10.245241.1.full
AB  - Humans are fast and accurate when they recognize familiar faces. Previous neurophysiological studies have shown enhanced representations for the dichotomy of familiar vs. unfamiliar faces. As familiarity is a spectrum, however, any neural correlate should reflect graded representations for more vs. less familiar faces along the spectrum. By systematically varying familiarity across stimuli, we show a neural familiarity spectrum using electroencephalography. We then evaluated the spatiotemporal dynamics of familiar face recognition across the brain. Specifically, we developed a novel informational connectivity method to test whether peri-frontal brain areas contribute to familiar face recognition. Results showed that feed-forward flow dominates for the most familiar faces and top-down flow was only dominant when sensory evidence was insufficient to support face recognition. These results demonstrate that perceptual difficulty and the level of familiarity influence the neural representation of familiar faces and the degree to which peri-frontal neural networks contribute to familiar face recognition.Competing Interest StatementThe authors have declared no competing interest.