The neural basis of rapid unfamiliar face individuation with human intracerebral recordings

Understanding human individuation of unfamiliar faces with oddball fast periodic visual stimulation and electroencephalography

“…The neural localization of the FI response was recently, more precisely explored by testing the paradigm in a large group ( N = 69) of temporal epileptic patients implanted with intracerebral EEG electrodes in the VOTC (Stereoelectroencephalography, SEEG; Jacques et al, 2020; Figure 10). Interestingly, significant responses found in lower‐level visual regions were eliminated when computing the difference between responses to upright versus inverted faces.…”

“…The neural basis of face individuation (from Jacques et al, 2020). (a) Intracerebral recordings (SEEG) in a large cohort ( N = 69) of temporal epilepsy patients presented with the oddball FPVS FI paradigm, at upright and inverted face orientations (Jacques et al, 2020; see Jonas et al, 2016; Rossion et al., 2018 for general methodological information). Across individual brains, a total of 3,825electrode contacts were recorded in the gray matter of the VOTC.…”

“…Moreover, fMRI only indirectly records neural activity, and the severe magnetic susceptibility artifacts arising from the ear canals seriously limits the ability of this method to explore VOTC regions located anteriorly to the mid‐fusiform gyrus, that is, the vATL (Axelrod & Yovel, 2013; Rossion, Jacques, & Jonas, 2018; Wandell, 2011). Hence, the more global exploration of the neural basis of FI afforded by the current oddball FPVS approach combined with human intracerebral recordings is especially valuable (Jacques et al, 2020).…”

“…A final line of evidence supporting the validity of our paradigm is the relationship between the oddball FI response and the effects of intracerebral electrical stimulation. Following such stimulation, a patient included in the study of Jacques et al (2020) experienced transient palinopsia limited to faces: She perceived facial features from a (variable from trial to trial) known familiar facial identity overlaid on the currently perceived face (a person or a picture in front of the patient; Jonas et al., 2018). The eloquent site of stimulation was located in the lateral section of the right middle fusiform gyrus, corresponding to the so‐called FFA (Kanwisher et al, 1997).…”

Intracerebral electrical stimulation to understand the neural basis of human face identity recognition

“…According to this hypothesis, thanks to their high connectivity, stimulating critical FIR nodes will lead to the stimulation current physiologically propagating to the whole (or a large part at least) of the FIR network, inducing a behavioral effect. This hypothesis provides to reconcile two main observations: on the one hand a large and widely distributed network supporting FIR responses across the VOTC (Jacques et al, 2020) and, on the other hand, the observations of (so far) "only" 3 critical regions identified among this distributed network. In the human brain, the dominance of the right hemisphere in face recognition mentioned at the beginning of the present review has been supported for decades by evidence collected with a variety of methods (lesion studies, divided visual field presentations, Positron Emission Tomography, fMRI, EEG, TMS, SEEG etc.)…”