title: Prefrontal activity measured by functional near infrared spectroscopy during probabilistic inference in subjects with persecutory delusions.
abstract: Jumping to conclusions (JTC) is a probabilistic reasoning bias and is thought to contribute to delusion formation. Neurobiological correlates of the JTC bias are not known. We aimed to examine the rostral prefrontal cortex (rPFC) activity with functional near ınfrared spectroscopy during a modified version of the Beads in a Jar Task (BIJT) in subjects with persecutory delusions (N=25). In BIJT participants are presented beads either drawn from one of the two jars with opposite probability ratios (PRs) of colored beads and are required to decide from which jar beads are being drawn. We administered the BIJT with 90/10 and 55/45 PRs. Compared to healthy controls (N=20), patients reached a decision earlier in both conditions. While the medial rPFC regions were more active in the 90/10 condition in controls compared to patients, lateral rPFC activation was higher in the 55/45 condition in patients than controls. Only in the control group, there was a marked decline in the lateral rPFC activation in the 55/45 condition compared to the 90/10 condition. The activity in the lateral rPFC was negatively correlated with the amount of beads drawn in healthy controls but not in subjects with persecutory delusions. Our results suggest that during the BIJT, rPFC does not function as a single unit and rather consists of functional subunits that are organized differently in patients and controls. The failure to deactivate the lateral rPFC may be associated with earlier decisions in subjects with persecutory delusions.
authors.affiliation: Ankara University School of Medicine Psychiatry Department, Ankara University Brain Research Center, TR06590, Dikimevi, Ankara, Turkey. Electronic address: baskak@medicine.ankara.edu.tr.
authors.forename: Bora
authors.initials: B
authors.lastname: Baskak
authors.affiliation: Hacettepe Universitesi Psikoloji Bölümü, Deneysel Psikoloji Laboratuarı, Beytepe, Ankara, Turkey. Electronic address: znbaran@hacettepe.edu.tr.
authors.forename: Zeynel
authors.initials: Z
authors.lastname: Baran
authors.affiliation: Ankara University School of Medicine Psychiatry Department, Ankara University Brain Research Center, TR06590, Dikimevi, Ankara, Turkey. Electronic address: ozguven@medicine.ankara.edu.tr.
authors.forename: Halise Devrimci
authors.initials: HD
authors.lastname: Ozguven
authors.affiliation: Ankara University School of Medicine Psychiatry Department, Ankara University Brain Research Center, TR06590, Dikimevi, Ankara, Turkey. Electronic address: isilkaraboga@hotmail.com.
authors.forename: Isil
authors.initials: I
authors.lastname: Karaboga
authors.affiliation: Ankara Universitesi, Tip Fakultesi, Cebeci Hastanesi, Çocuk Ruh Sağlığı ve Hastalıkları Anabilim Dali, TR06590, Dikimevi, Ankara, Turkey. Electronic address: ozgur.oner@yahoo.com.
authors.forename: Ozgur
authors.initials: O
authors.lastname: Oner
authors.affiliation: Ankara University School of Medicine Psychiatry Department, Ankara University Brain Research Center, TR06590, Dikimevi, Ankara, Turkey. Electronic address: Erguvan.Tugba.Ozel.Kizil@ankara.edu.tr.
authors.forename: Erguvan Tugba
authors.initials: ET
authors.lastname: Ozel Kizil
authors.affiliation: Ankara University School of Medicine Psychiatry Department, Ankara University Brain Research Center, TR06590, Dikimevi, Ankara, Turkey. Electronic address: ysmnhosgoren@hotmail.com.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Hosgoren
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015982:Bias; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007600:Judgment; D008297:Male; D017397:Prefrontal Cortex / Q000378:metabolism*; D011336:Probability; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications; D012563:Schizophrenia, Paranoid / Q000150:complications / Q000473:pathology*; D019265:Spectroscopy, Near-Infrared; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D006454:Hemoglobins
keywords: Functional near infrared spectroscopy; Persecutory delusions; Probabilistic reasoning