A Robust Neural Index of High Face Familiarity

Abstract

Humans are remarkably accurate at recognising familiar faces, while their ability to recognize, or even match, unfamiliar faces is much poorer. However, previous research has failed to identify neural correlates of this striking behavioural difference. Here we show a clear difference in brain potentials elicited by highly familiar faces versus unfamiliar faces. This effect starts 200 ms after stimulus onset and reaches its maximum at 400-600 ms. This Sustained Familiarity Effect is substantially larger than previous candidates for a neural familiarity marker and is detected in almost all participants, representing a reliable index of high familiarity. While its scalp distribution is consistent with a generator in the ventral visual pathway, its modulation by repetition and degree of familiarity suggests an integration of affective and visual information.

Later but not early stages of familiar face recognition depend strongly on attentional resources: Evidence from event-related brain potentials

“…As yet, relatively little is known about the SFE. The effect can be measured without an explicit familiarity response by the participants, but its magnitude decreases with image repetition, which suggests that it is not bound to a particular stimulus presentation (Wiese, Tüttenberg, et al, 2019). Importantly, the SFE is substantially larger than previous ERP markers of familiarity.…”

“…We recently observed a further familiarity effect between 400 and 600ms at occipitotemporal electrodes (Wiese, Tüttenberg, et al, 2019). This Sustained Familiarity Effect (SFE) was found when testing participants with multiple so-called ambient images which contain "naturalistic" within-person variability (see Figure 1).…”

“…If, however, facial identity at the SFE level was processed even in the letter task, we would assume a corresponding familiarity effect in the first (and second) block. Moreover, as we have found that the SFE is reduced with image repetition (Wiese, Tüttenberg, et al, 2019), we always presented the letter task first to prevent a reduction of the effect by a previous presentation of the pictures.…”

“…Although we offered this account of the SFE in general (Wiese, Tüttenberg, et al, 2019), an alternative possibiulity for the lack of an SFE to celebrity faces is that participants might not have recognized all of the highly variable ambient images of the celebrities, which did elicit somewhat more negative responses than unfamiliar faces. Therefore, the non-significant result for celebrity faces might conceivably have been caused by a subgroup of participants not being sufficiently familiar with the used celebrities, and whether it is possible to show an SFE for celebrity faces remains an open question.…”

Face learning via short real-world social interactions induces changes in face-selective brain areas and hippocampus

“…For example, the N250r eventrelated potential (ERP) component, recorded over the inferior temporal regions, is modulated by repetitions of face stimuli which is greater for familiar (famous) than unfamiliar faces (Schweinberger et al, 2002, Schweinberger et al, 2004. A more recent EEG study also demonstrated a robust dissociation in the neural response to personally familiar, versus unfamiliar faces that ranged from 200 to 600 milliseconds after stimulus onset (Wiese et al, 2019). Studies have also shown that faces can become familiar over the course of an experiment resulting in differences between familiar and unfamiliar faces in ERP components (especially the N250).…”