title: Distinguishing shyness and sociability in adults: An event-related electrocortical-neuroendocrine study.
abstract: Shyness and sociability are orthogonal personality dimensions, but little is known about how the two traits are instantiated in the brain and body. Using a 3-stimulus auditory oddball task, we examined whether shyness and sociability were distinguishable on P300 event-related potentials (ERPs) in processing task-relevant, novel, and standard auditory tones in 48 young adults. ERP amplitudes were measured at four midline scalp sites (Fz, FCz, Cz, Pz). We found that shyness, but not sociability, was related to reduced frontal novelty P300 amplitudes and to high emotionality. We also found that low baseline salivary cortisol levels mediated the relation between: (a) high shyness and reduced frontal P300 amplitudes to novel tones, and (b) high shyness and high scores of emotionality. We speculate that low baseline cortisol may serve as a putative mechanism influencing central attentional states of avoidance to threat and novelty and emotional arousal in adults who are shy.
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada. Electronic address: tanga6@mcmaster.ca.
authors.forename: Alva
authors.initials: A
authors.lastname: Tang
authors.affiliation: Department of Psychology, University of Winnipeg, Winnipeg, Manitoba, Canada.
authors.forename: Diane L
authors.initials: DL
authors.lastname: Santesso
authors.affiliation: Department of Psychology, Brock University, St. Catharines, Ontario, Canada.
authors.forename: Sidney J
authors.initials: SJ
authors.lastname: Segalowitz
authors.affiliation: Department of Neuroscience, Center for the Brain Basis for Cognition and School of Medicine, Georgetown University, Washington, DC, United States.
authors.forename: Jay
authors.initials: J
authors.lastname: Schulkin
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Louis A
authors.initials: LA
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology; D001362:Avoidance Learning / Q000502:physiology; D001481:Basal Metabolism / Q000502:physiology; D001921:Brain / Q000502:physiology; D004644:Emotions / Q000502:physiology*; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism; D008297:Male; D009489:Neurosecretion / Q000502:physiology; D012792:Shyness; D012919:Social Behavior; D066107:Social Skills; D055815:Young Adult
chemical_list: D006854:Hydrocortisone
keywords: ERP; Emotionality; Novelty P300; Salivary cortisol; Shyness; Sociability