Face Familiarity Decisions Take 200 msec in the Human Brain: Electrophysiological Evidence from a Go/No-go Speeded Task

Abstract

Recognizing a familiar face rapidly is a fundamental human brain function. Here we used scalp EEG to determine the minimal time needed to classify a face as personally familiar or unfamiliar. Go (familiar) and no-go (unfamiliar) responses elicited clear differential waveforms from 210 msec onward, this difference being first observed at right occipito-temporal electrode sites. Similar but delayed (by about 40 msec) responses were observed when go response were required to the unfamiliar rather than familiar faces, in a second group of participants. In both groups, a small increase of amplitude was also observed on the right hemisphere N170 face-sensitive component for familiar faces. However, unlike the post-200 msec differential go/no-go effect, this effect was unrelated to behavior and disappeared with repetition of unfamiliar faces. These observations indicate that accumulation of evidence within the first 200 msec poststimulus onset is sufficient for the human brain to decide whether a person is familiar based on his or her face, a time frame that puts strong constraints on the time course of face processing.

Spatio-temporal dynamics and laterality effects of face inversion, feature presence and configuration, and face outline

“…The M240 deflection engages distributed anterior temporal cortices and may index familiarity detection and recognition, supporting previous iEEG findings (Barbeau et al, 2008). Furthermore, recent evidence shows that the (presumably analogous) N250 is sensitive not only to familiarity (Caharel et al, 2014), but that it emerges to previously unfamiliar faces as a result of repetition and, consequently, familiarization (Tanaka et al, 2006; Schweinberger et al, 2007; Pierce et al, 2011; Zimmermann and Eimer, 2013). Even though we did not manipulate repetition in a condition-specific manner, the present results are consistent with the idea that this deflection may reflect access to recognition units and activation of a memory trace for the particular face that has become familiar with repetition (Zimmermann and Eimer, 2013).…”

Neural microgenesis of personally familiar face recognition

“…Humans are capable of astonishing performances; for example, they can identify individuals despite not having seen them for decades (1) and can tell apart familiar from unfamiliar faces in a few hundred milliseconds (2,3). However, face recognition is one of the most difficult operations performed by the human brain: performance is highly variable across typical individuals (4,5) and can be severely disrupted following right occipitotemporal brain damage ("prosopagnosia") (6)(7)(8) or atypical development ("congenital/developmental prosopagnosia") (9,10).…”

Familiarity Facilitates Feature-based Face Processing

“…Moreover, social cues, such as eyegaze or head orientation, are processed faster when conveyed by familiar faces [14]. With a saccadic reaction paradigm, we found that participants were able to detect and shift their gaze to familiar faces in 180 ms [15] when the distractors were faces of strangers, a latency shorter a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 than the known evoked potentials that differentiate familiar from stranger faces [16]; but see [17]). Overall, these results highlight a difference in processing between familiar and unfamiliar faces and point to a facilitation of familiar face processing that precedes the activation of a conscious, view-invariant representation [13,15], and that extends to the local features of a familiar face [12,14].…”