title: Categorical perception of familiarity: Evidence for a hyper-familiarity in schizophrenia.
abstract: Familiarity is a crucial aspect of recognition that may be perturbed in schizophrenia patients (SZP) and may lead to delusional disorders. However, there are no existing guidelines on how to assess and treat familiarity disorders in schizophrenia. Some experimental studies have investigated familiarity processing in SZP but have produced inconsistent results, which are likely a result of methodological issues. Moreover, these studies only assessed whether familiarity processing is preserved or impaired in SZP, but not the tendency of SZP to consider unfamiliar stimuli to be familiar. By using a familiarity continuum task based on the existence of the categorical perception effect, the objective of this study was to determine whether SZP present hyper- or hypo-familiarity. To this purpose, 15 SZP and 15 healthy subjects (HS) were presented with facial stimuli, which consisted of picture morphs of unfamiliar faces and faces that were personally familiar to the participants. The percentage of the familiar face contained in the morph ranged from 5 to 95%. The participants were asked to press a button when they felt familiar with the face that was presented. The main results revealed a higher percentage of familiarity responses for SZP compared with HS from the stimuli with low levels of familiarity in the morph and a lower familiarity threshold, suggesting a hyper-familiarity disorder in SZP. Moreover, the intensity of this "hyper-familiarity" was correlated with positive symptoms. This finding clearly suggests the need for a more systematic integration of an assessment of familiarity processing in schizophrenia symptoms assessments.
authors.affiliation: Université de Lille, Laboratoire Sciences Cognitives Sciences Affectives (ScaLab), UMR 9193 CNRS, F-59000 Lille, France; Centre Hospitalier Universitaire de Lille (CHULille), Hôpital Fontan, F-59037 Lille, France. Electronic address: horn.mathilde@gmail.com.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Horn
authors.affiliation: Laboratory for Experimental Psychopathology, Psychological Sciences Research Institute, Université Catholique de Louvain, Louvain-La-Neuve, Belgium.
authors.forename: Fabien
authors.initials: F
authors.lastname: D'Hondt
authors.affiliation: Université de Lille, Laboratoire Sciences Cognitives Sciences Affectives (ScaLab), UMR 9193 CNRS, F-59000 Lille, France; Centre Hospitalier Universitaire de Lille (CHULille), Hôpital Fontan, F-59037 Lille, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Vaiva
authors.affiliation: Université de Lille, Laboratoire Sciences Cognitives Sciences Affectives (ScaLab), UMR 9193 CNRS, F-59000 Lille, France; Centre Hospitalier Universitaire de Lille (CHULille), Hôpital Fontan, F-59037 Lille, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Thomas
authors.affiliation: Université de Lille, Laboratoire Sciences Cognitives Sciences Affectives (ScaLab), UMR 9193 CNRS, F-59000 Lille, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Pins
mesh_terms: D000328:Adult; D000066499:Facial Recognition; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011581:Psychological Tests; D021641:Recognition, Psychology; D012559:Schizophrenia; D012565:Schizophrenic Psychology
keywords: Categorical perception; Familiarity; Morph; Schizophrenia