Rapid neural representations of personally relevant faces

Abstract

Faces are a primary source of social information, but little is known about the sequence of neural processes that extract information from highly personally relevant faces, such as those of our loved ones. We applied representational similarity analyses to EEG-fMRI measurement of neural responses to faces of personal relevance to participants -their romantic partner and a friend -compared to a stranger. Faces expressed fear, happiness or no emotion. Shared EEG-fMRI representations started 100ms after stimulus onset not only in visual cortex, but also regions involved in social cognition, value representation and autobiographical memory, including ventromedial prefrontal cortex, temporoparietal junction and posterior cingulate. Representations in fusiform gyrus, amygdala, insular cortex and N. accumbens were evident after 200 ms. Representations related to romantic love emerged after 400ms in subcortical brain regions associated with reward. The results point to the prioritized processing of personal relevance with rapid and extensive cortical representation.3 Faces are arguably the most important social and emotional stimuli we encounter in daily life. They tell us an enormous amount about our fellow humans, including whether they are strangers, friends, enemies, or loved ones, how old they are, how healthy they are, and how they are feeling, both generally, as well as towards us specifically. So important are faces to us, that we appear to be experts at processing them, and have developed specialised neural circuitry to do so (Kanwisher, 2000). Based on a large body of behavioural and neuroimaging research, theories of how different types of face information are extracted from the visual stream have been proposed, with separate processing pathways being suggested for transient (e.g. emotion) and stable (e.g. identity) aspects of faces (Bruce & Young, 1986). Yet testing these models is hampered by the lack of temporal resolution needed to delineate several rapidly occurring processing stages, and the almost exclusive focus on faces that carry little or no personal relevance to the observer.

Socially induced negative affective knowledge modulates early face perception but not gaze cueing of attention

“…1.1 | The influence of prior social knowledge on early perceptual stages of face processing Prior knowledge and experiences have been repeatedly shown to modulate very early (even less than 100 ms after stimulus onset) neural responses (Abdel Rahman & Sommer, 2008;Bao et al, 2010;Bar et al, 2006;Chaumon et al, 2008Chaumon et al, , 2009Gamond et al, 2011;Pourtois et al, 2008). Specifically in the social domain, familiarity and personal relevance have previously been observed to exert an important influence on visual processing of faces (Ramon & Gobbini, 2018), for example, dramatically facilitating recognition (Natu & O'Toole, 2011) and enhancing early neural processing (e.g., increased P1 amplitudes in Bayer et al, 2021). Crucially, discrimination of facial identity, which requires prior social and semantic knowledge, has been reported to occur very early (even as early as 70 ms after stimulus onset; Nemrodov et al, 2016), especially for familiar (as compared to unfamiliar) faces (Dobs et al, 2019).…”