An objective index of individual face discrimination in the right occipito-temporal cortex by means of fast periodic oddball stimulation

• Published in: Neuropsychologia Vol. 52; pp. 57 - 72
• Main Authors: Liu-Shuang, Joan, Norcia, Anthony M., Rossion, Bruno
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2014; Elsevier
• Subjects: Adult; Behavioral psychophysiology; Biological and medical sciences; Biophysics; Discrimination (Psychology) - physiology; EEG; Electroencephalography; Electrophysiology; Evoked Potentials - physiology; Face; Face discrimination; Female; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Humans; Male; Neuropsychological Tests; Occipital Lobe - physiology; Occipito-temporal cortex; Pattern Recognition, Visual - physiology; Periodic visual stimulation; Photic Stimulation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Steady-state visual evoked potentials; Temporal Lobe - physiology; Young Adult; Steady-state visual evoked potentials; Periodic visual stimulation; Occipito-temporal cortex; EEG; Face discrimination; Human; Central nervous system; Electrophysiology; Visual evoked potential; Stimulation; Cognition; Temporal cortex; Electroencephalography; Experimental study; Encephalon; Occipital cortex; Vision; Perception; Face; Stimulus discrimination
• ISSN: 0028-3932; 1873-3514; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2013.10.022

We introduce an approach based on fast periodic oddball stimulation that provides objective, high signal-to-noise ratio (SNR), and behavior-free measures of the human brain's discriminative response to complex visual patterns. High-density electroencephalogram (EEG) was recorded for human observers presented with 60s sequences containing a base-face (A) sinusoidally contrast-modulated at a frequency of 5.88Hz (F), with face size varying every cycle. Different oddball-faces (B, C, D…) were introduced at fixed intervals (every 4 stimuli=F/5=1.18Hz: AAAABAAAACAAAAD…). Individual face discrimination was indexed by responses at this 1.18Hz oddball frequency. Following only 4min of recording, significant responses emerged at exactly 1.18Hz and its harmonics (e.g., 2F/5=2.35Hz, 3F/5=3.53Hz…), with up to a 300% signal increase over the right occipito-temporal cortex. This response was present in all participants, for both color and greyscale faces, providing a robust implicit neural measure of individual face discrimination. Face inversion or contrast-reversal did not affect the basic 5.88Hz periodic response over medial occipital channels. However, these manipulations substantially reduced the 1.18Hz oddball discrimination response over the right occipito-temporal region, indicating that this response reflects high-level processes that are partly face-specific. These observations indicate that fast periodic oddball stimulation can be used to rapidly and objectively characterize the discrimination of visual patterns and may become invaluable in characterizing this process in typical adult, developmental, and neuropsychological patient populations. •Fast periodic oddball stimulation can index high-level visual discrimination.•Responses to periodic oddball faces in a trial of same faces reflect discrimination.•We found oddball responses in the right occipito-temporal region in single subjects.•Oddball responses significantly decreased for inverted and contrast-reversed faces.•This approach is useful to study visual discrimination in a variety of populations.