A robust neural index of automatic generalization across variable natural views of familiar face identities

ABSTRACT

The ability to automatically and rapidly recognize a familiar face identity across different views is well documented but generally measured with explicit behavioural tasks involving many other processes. Here we provide a sensitive implicit neural measure of this ability using electroencephalographic (EEG) recordings coupled with fast periodic visual stimulation (FPVS). Images of two famous face identities alternated for 15 seconds at a frequency rate of 6 Hz, preceded by a 15 seconds adaptation period to images of one of the face identities. Beyond previous studies, numerous (N = 60) non-edited variable natural face images of each identity were presented, with different images appearing at adaptation (N = 30) and test. At the group-level (N = 16), 3 stimulation sequences only were sufficient to elicit highly significant EEG peaks at odd harmonics (3 and 9 Hz), reflecting face identity discrimination across variable novel views. This response was maximally localized over the right occipito-temporal region and statistically significant in 75% of individuals tested. Importantly, the face identity discrimination response at odd harmonics was significantly larger than when the exact same stimulation sequences were preceded by images of a face identity not present in the alternating sequence (irrelevant adaptation condition). Overall, this study provides a highly sensitive and objective technique to implicitly measure an individual’s ability to generalize identity across different views of a familiar face identity.

KEYWORDS:

• Famous face identity recognition
• visual adaptation
• electroencephalography
• fast periodic visual stimulation

Acknowledgements

The authors would like to thank Holger Wiese and an anonymous reviewer for very helpful comments on a previous version of this manuscript. Justine David: Formal analysis, Data curation, Methodology, Investigation, Visualization, Writing – original draft, Writing – review & editing; Laurent Koessler: Funding acquisition, Methodology, Writing – review & editing; Supervision; Bruno Rossion: Conceptualization, Funding acquisition, Methodology, Supervision, Writing – original draft, Writing – review & editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by European Research Council: [Grant Number ADG HUMANFACE 101055175]; CIFRE Bioserenity: [Grant Number 2021/0405].