title: Somatosensory processing in the biological relatives of schizophrenia patients: a signal detection analysis of two-point discrimination.
abstract: This study examined 2-point discrimination performance in 1 st-degree biological relatives (n = 39) of individuals with schizophrenia and normal adult control participants (n = 30) recruited from the community. They completed an objective 2-point discrimination task, adapted for use with a signal detection approach to permit separation of discriminability (i.e., sensitivity, d') from response bias/ criterion (or motivation, lnbeta). Relatives revealed poorer performance on the d' index compared with controls. The 2 groups did not differ on lnbeta, suggesting a genuine difference in sensitivity but not response bias. The sensitivity deficit might reflect decreased spatial acuity and/or impaired intensity cue processing of tactile stimuli. Poor performance on the d' index was most closely associated with 2 schizotypic features, namely "odd beliefs/magical thinking."
authors.affiliation: Department of Psychology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: B P
authors.initials: BP
authors.lastname: Chang
authors.forename: M F
authors.initials: MF
authors.lastname: Lenzenweger
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004192:Discrimination, Psychological; D005190:Family / Q000523:psychology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000235:genetics*; D012565:Schizophrenic Psychology; D012684:Sensory Thresholds; D017603:Signal Detection, Psychological; D014110:Touch