title: Habituation of the startle reflex depends on attention in cannabis users.
abstract: BACKGROUND
  Cannabis use is associated with an attention-dependent deficit in prepulse inhibition of the startle reflex (PPI). The aim of the current study was to investigate startle habituation in cannabis users and healthy controls during two attentional tasks.
  
  
  METHODS
  Auditory startle reflex was recorded from orbicularis oculi muscle while participants (12 controls and 16 regular cannabis users) were either attending to or ignoring 100 dB startling pulses. Startle habituation was measured as the absolute reduction in startle magnitude on block 2 (last nine trials) vs. block 1 (first nine trials).
  
  
  RESULTS
  Startle habituation with moderate effect sizes was observed in controls and cannabis users only while they were ignoring the startling pulses but not while they were attending to them. Similar results were also observed in controls (lifetime non-users of cannabis) and cannabis users with lifetime cannabis use disorders (CUD).
  
  
  CONCLUSIONS
  Startle habituation appears to depend on selective attention but not on cannabis use. Startle habituation was present when attention was directed away from auditory startling pulses in healthy controls and cannabis users. Such a similar pattern of results in both groups suggests that at least a trend exists towards presence of startle habituation regardless of cannabis use or CUD in otherwise healthy members of the general population.
authors: Institute of Psychology and Transfer, University of Bremen, (FB 11), Grazer Str. 2c, 28359, Bremen, Germany. kkedzior@graduate.uwa.edu.au.|School of Engineering and Science, Jacobs University Bremen, Bremen, Germany. kkedzior@graduate.uwa.edu.au.|Clinical Neurophysiology Unit, Graylands Hospital and Pharmacology & Anaesthesiology Unit, School of Medicine & Pharmacology, Faculty of Medicine, Dentistry & Health Sciences, The University of Western Australia, Perth, Australia. kkedzior@graduate.uwa.edu.au.
authors: Karina K
authors: KK
authors: Kedzior
authors: School of Engineering and Science, Jacobs University Bremen, Bremen, Germany.
authors: Eileen
authors: E
authors: Wehmann
authors: Clinical Neurophysiology Unit, Graylands Hospital and Pharmacology & Anaesthesiology Unit, School of Medicine & Pharmacology, Faculty of Medicine, Dentistry & Health Sciences, The University of Western Australia, Perth, Australia.
authors: Mathew
authors: M
authors: Martin-Iverson
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001288:Attention / Q000187:drug effects*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000503:physiopathology* / Q000523:psychology*; D008385:Marijuana Smoking / Q000503:physiopathology / Q000523:psychology; D013216:Reflex, Startle / Q000187:drug effects*; D055815:Young Adult
keywords: Cannabis misuse; Selective attention; Startle habituation