title: The time course of individual face recognition: A pattern analysis of ERP signals.
abstract: An extensive body of work documents the time course of neural face processing in the human visual cortex. However, the majority of this work has focused on specific temporal landmarks, such as N170 and N250 components, derived through univariate analyses of EEG data. Here, we take on a broader evaluation of ERP signals related to individual face recognition as we attempt to move beyond the leading theoretical and methodological framework through the application of pattern analysis to ERP data. Specifically, we investigate the spatiotemporal profile of identity recognition across variation in emotional expression. To this end, we apply pattern classification to ERP signals both in time, for any single electrode, and in space, across multiple electrodes. Our results confirm the significance of traditional ERP components in face processing. At the same time though, they support the idea that the temporal profile of face recognition is incompletely described by such components. First, we show that signals associated with different facial identities can be discriminated from each other outside the scope of these components, as early as 70ms following stimulus presentation. Next, electrodes associated with traditional ERP components as well as, critically, those not associated with such components are shown to contribute information to stimulus discriminability. And last, the levels of ERP-based pattern discrimination are found to correlate with recognition accuracy across subjects confirming the relevance of these methods for bridging brain and behavior data. Altogether, the current results shed new light on the fine-grained time course of neural face processing and showcase the value of novel methods for pattern analysis to investigating fundamental aspects of visual recognition.
authors.affiliation: Department of Psychology at Scarborough, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada. Electronic address: dan.nemrodov@utoronto.ca.
authors.forename: Dan
authors.initials: D
authors.lastname: Nemrodov
authors.affiliation: Department of Psychology at Scarborough, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada.
authors.forename: Matthias
authors.initials: M
authors.lastname: Niemeier
authors.affiliation: Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada.
authors.forename: Jenkin Ngo Yin
authors.initials: JNY
authors.lastname: Mok
authors.affiliation: Department of Psychology at Scarborough, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Nestor
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010363:Pattern Recognition, Automated; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: ERP; N170; P1; Pattern analysis; Time course; Visual face recognition