title: Startle magnitude and prepulse inhibition: effects of alcohol and attention.
abstract: BACKGROUND
  Previous studies of the effects of attention on prepulse inhibition (PPI) have not accounted for the effects of attention on control (i.e. pulse alone) trials. In addition, there have been no studies of the effects of alcohol on the attentional modulation of PPI, even though alcohol putatively influences attentional mechanisms. The objective of the present study was to examine the effects of alcohol on the attentional modulation of PPI, using an experimental paradigm that controlled for the effects of attention on control trials.
  
  
  METHODS
  Participants completed two experimental sessions spaced 1 week apart and consumed either three alcoholic drinks (target BAL=0.06) or three non-alcoholic drinks. Participants were exposed to a series of prepulse and pulse alone stimuli and were instructed to either listen or ignore prior to each stimulus.
  
  
  RESULTS
  Repeated measures ANOVAs suggested that attention increased PPI and startle magnitude on pulse alone control trials. Alcohol decreased both startle magnitude and PPI. There was no significant interaction between attention and alcohol.
  
  
  CONCLUSIONS
  These findings suggest that both startle magnitude and PPI are increased by attention and that failure to control for the effects of attention on control trials may result in an underestimation of the effect of attention on PPI. Furthermore, the effect of alcohol on attention does not appear to generalize to the voluntary attentional processes involved in the attentional modulation of PPI.
authors.affiliation: Department of Psychology, Muenzinger Psychology Building, University of Colorado, Boulder 80309-0345, USA. KentH@psych.colorado.edu
authors.forename: Kent E
authors.initials: KE
authors.lastname: Hutchison
authors.forename: John
authors.initials: J
authors.lastname: McGeary
authors.forename: Angela
authors.initials: A
authors.lastname: Wooden
authors.forename: Terry
authors.initials: T
authors.lastname: Blumenthal
authors.forename: Tiffany
authors.initials: T
authors.lastname: Ito
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects* / Q000502:physiology; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D008297:Male; D010812:Physical Stimulation; D011930:Reaction Time; D013216:Reflex, Startle / Q000187:drug effects* / Q000502:physiology; D016037:Single-Blind Method
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol