Differences in startle reflex and prepulse inhibition in European-Americans and African-Americans

• Authors: Wendy Hasenkamp, Atlanta Department of Veterans Affairs Medical Center; Seth Davin Norrholm, Emory University; Amanda Green, Atlanta Department of Veterans Affairs Medical Center; Barbara Lewison, Atlanta Department of Veterans Affairs Medical Center; William Boshoven, Atlanta Department of Veterans Affairs Medical Center; Megan Keyes, Atlanta Department of Veterans Affairs Medical Center; Erica Duncan, Emory University
• Journal Title: Psychophysiology
• Volume: Volume 45, Number 5
• Publisher: Wiley: 12 months | 2008-09-01, Pages 876-882
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1111/j.1469-8986.2008.00680.x
• Subjects: Health Sciences, Mental Health; Psychology, Psychobiology; Biology, Neuroscience
• Keywords: Social Sciences; Science & Technology; Life Sciences & Biomedicine; Psychology, Biological; Neurosciences; Physiology; Psychology; Psychology, Experimental; Neurosciences & Neurology; startle reflex; prepulse inhibition; race; European; African; INBRED MOUSE STRAINS; ACOUSTIC STARTLE; MENSTRUAL-CYCLE; SENSORIMOTOR; MODULATION; MICE; SCHIZOPHRENIA; HABITUATION; DISORDERS; STRESS

Abstract

The acoustic startle reflex and its modulation by a prepulse are psychophysiological phenomena that are commonly studied to evaluate various aspects of information processing. Recent reports in human populations suggest that subjects from disparate racial backgrounds may have significant differences in the startle response. To determine if this pattern could be observed in our subject population and whether it extended to prepulse inhibition (PPI), we evaluated baseline startle parameters and PPI in 53 African-Americans (AA) and 38 European-Americans (EA). In AA compared to EA, mean startle magnitude and probability of blink response were lower, with no difference in habituation. PPI was greater in AA than EA when groups were matched on baseline startle magnitude. These findings support the idea of racial differences in startle response. Implications for study design are highlighted, and possible environmental and genetic influences are considered.