title: Prepulse facilitation and prepulse inhibition in schizophrenia patients and their unaffected siblings.
abstract: BACKGROUND
  Deficits in schizophrenia patients and their first-degree relatives have been reported in prepulse inhibition (PPI), a phenomenon that measures an early stage of information processing (sensorimotor gating). It is less clear whether these information processing deficits extend to prepulse facilitation (PPF), which measures a later stage of generalized alerting or orienting.
  
  
  METHODS
  This study examined three separate issues: first, whether schizophrenia patients have deficits in PPI and PPF; second, whether the siblings of patients show deficits in these processes; and third, whether prepulse duration influences the degree of the deficits. These issues were examined in 76 schizophrenia patients, 36 of their siblings, and 41 normal control subjects.
  
  
  RESULTS
  Patients and siblings did not differ from control subjects in PPI, perhaps due to the use of different procedural parameters compared with other laboratories that have consistently found PPI deficits in schizophrenia patients. Patients and their siblings produced significantly less PPF than control subjects. For both PPI and PPF, prepulse duration was not a significant factor.
  
  
  CONCLUSIONS
  These results imply that PPF deficits reveal a generalized alerting or orienting deficit that is present in both schizophrenia patients and their siblings, suggesting that this deficit may be tapping an endophenotypic vulnerability factor.
authors.affiliation: Department of Psychology (MED), University of Southern California, Los Angeles, California 90073, USA.
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Wynn
authors.forename: Michael E
authors.initials: ME
authors.lastname: Dawson
authors.forename: Anne M
authors.initials: AM
authors.lastname: Schell
authors.forename: Mark
authors.initials: M
authors.lastname: McGee
authors.forename: Dustin
authors.initials: D
authors.lastname: Salveson
authors.forename: Michael F
authors.initials: MF
authors.lastname: Green
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D012016:Reference Values; D013216:Reflex, Startle; D012559:Schizophrenia / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D035781:Siblings / Q000523:psychology