Supplemental Table 1. Review of Studies of Voice Identity Processing in Schizophrenia and Its Relationship with AVH

SZ vs. HC
Author / Sample size and features / Subtypes / Method and design / Results
(Ford, Mathalon, Kalba, et al., 2001b)89 / 10 HC; 12 SZ (a, e) / 4 P; 6U; 1D; 1 R / ERP - responses to acoustic probes during talking vs. listening / SZ ≠ HC
(Ford, Mathalon, Heinks, et al., 2001)92 / 7 HC; 7 SZ (N.A.) / N.A. / ERP - talking aloud vs. listening / SZ ≠ HC
(Ford, Mathalon, Kalba, et al., 2001a)90 / 15 HC; 15 SZ (a, e) / N.A. / ERP - inner speech vs. listening / SZ ≠ HC
(Ford & Mathalon, 2005)87 / Aims 3 and 4: 21 HC; 20 SZ (a, e)
(aims 1 and 2 inFord, Mathalon, Kalba, et al., 2001b) / N.A. / EEG coherence - talking vs. listening / SZ ≠ HC
(Ford, Roach, Faustman, & Mathalon, 2007)96 / 25 HC; 24 SZ/SAD (e) / 10 U; 9 P; 3 SAD; 2 R / ERP and EEG coherence - talking vs. listening to self-generated voice. / SZ ≠ HC;
Neural synchrony anomalies↔ AH severity
(Rotarska-Jagiela et al., 2009)82 / 24 HC; 24 SZ with AVH (c, d) / N.A. / DTI / SZ ≠ HC
(Kumari et al., 2010)65 / 20 HC; 63 SZ (c) / N.A. / fMRI - identity judgment of vocal feedback during reading / SZ ≠ HC; Good ≠ bad performers;
brain functioning anomalies ↔ AH severity
(Whitford et al., 2011)83 / 25 HC ; 21 SZ (e) / N.A. / ERP - self-induced vocal stimuli by button press; DTI / SZ ≠ HC
(Simons et al., 2010)72 / 12 HC; 15 SZ with AVH (during illness exacerbations) / N.A. / fMRI - listening vs. inner speech generation / SZ ≠ HC
(Ilankovic et al., 2011)67 / 23 HC; 23 SZ with AVH ( ≥3 score) (a) / N.A. / Behavioral - voice identity judgment preceded by a congruent/incongruent cue / SZ ≠ HC;
misattribution errors ↔delusional severity
AVH vs. NAVH
Author / Sample size and features / Subtypes / Method and design / Results
(Johns et al., 2001)23 / 20 HC; 10 AVH (current) (a); 8 NAVH (i) / N.A. / Behavioral - identity judgment of vocal feedback during reading / SZ ≠ HC; AVH ≠ NAVH;
(Ford, Mathalon, Whitfield, Faustman, & Roth, 2002)95 / 10 HC; 7 AVH (5-7 score)(e, a); 5 NAVH (1-2 score)(e, a) / 4 P, 6 U, 1 D, 1 R / EEG coherence - responses to acoustic probes during talking vs. listening / AVH ≠ NAVH / HC;
(Allen et al., 2004)33 / 15 HC; 15 AVH (current & ≥3 score) (a); 13 NAVH (no current & 0 score) (a) / N.A. / Behavioral - voice identity judgment / AVH ≠ NAVH / HC
(Hubl et al., 2004)81 / 13 HC; 13 AVH (current) (d); 13 non-AVH (no history) / N.A. / DTI / AVH ≠ NAVH / HC
(Johns et al., 2006)24 / 20 HC; 10 AP with AVH; 15 SZ/SAD with AVH (current)(a) ; 15 SZ/SAD with AVH history (i) ; 15 SZ /SAD without AVH history (i) / N.A. / Behavioral - identity judgment of vocal feedback during reading / SZ/SAD with AVH ≠ HC / SZ/SAD with AVH history / AP with AVH
(Allen, Amaro, et al., 2007)28 / 11 HC; 10 AVH (past week & ≥3 score )(a); 10 non-AVH (no history) / N.A. / fMRI - voice identity judgment / AVH ≠ NAVH / HC
(Heinks-Maldonado et al., 2007)69 / 17 HC; 20 SZ: 10 AVH (past 4 weeks) (a); 10 NAVH (absent for the last 4 weeks & ≤1 score)(a) / N.A. / ERP - identity judgment of vocal feedback during talking / AVH ≠ NAVH / HC
(Mechelli et al., 2007)68 / 10 HC; 11 AVH (past week)(a); 10 NAVH (no history) / N.A. / fMRI & DCM - voice identity judgment / SZ ≠ HC; AVH ≠ NAVH / HC
(Fu et al., 2008)70 / 13 HC; 10 AVH; 10 NAVH / N.A. / fMRI - identity judgment of vocal feedback / AVH ≠ NAVH / HC
(Zhang et al., 2008)30 / 13 HC; 26 SZ: 13 AVH; 13 NAVH (a) / P / fMRI - familiar vs. unfamiliar voices discrimination / AVH ≠ HC
(Alba-ferrara, Weis, Damjanovic, Rowett, & Hausmann, 2012)29 / 13 HC; 13 AVH (current & ≥3 score) (a); 12 NAVH (no current & ≤1score) (a) / N.A. / Behavioral - famous voices recognition / SZ ≠ HC; AVH ≠ NAVH;
(Chhabra, Badcock, Maybery, & Leung, 2012)31 / 34 HC; 65 SZ/SZ spectrum disorder: 33 AVH (current) (b); 32 NAVH (no current) / N.A. / Behavioral - similarity judgment between voices / SZ ≠ HC
(Mou et al., 2013)64 / 13 HC; 13 AVH (past 2 weeks & ≥4 score)(a); 13 NAVH (no history & 0 score)(a) / N.A. / fMRI- identity judgment of familiar vs. unfamiliar voices / AVH ≠ NAVH / HC

Note. SZ=schizophrenia; NAVH=without AVH; SAD=schizoaffective disorder; AP=affective psychosis; P=paranoid; U=undifferentiated; D=disorganized; R=Residual; PNOS=psychosis not otherwise specified; SZP=schizophreniform; SZD=Schizoid; FEP= First-episode: N.A. = NON APPLICABLE; AH=auditory hallucinations

a Scale for the Assessment of Positive Symptoms – SAPS (Andreasen, 1984);97b Psychotic Symptom Rating Scales(Haddock, McCarron, Tarrier, & Faragher, 1999);98 c Positive and Negative Syndrome Scale – PANSS(Kay, S R Fiszbein & Opler, 1987);99d Semi-structured interview; e Brief Psychiatric Rating Scale – BPRS (Overall, 1961);100 f Modified version of the Present State Examination(Wing et al., 1990);101 g Topography of Voices Rating Scale(Husting & Hafner, 1990);102 h Launay-Slade Hallucination Scale(Bentall & Slade, 1986);103 i Assessed by case-notes and patients self-report.