Self-voice perception and its relationship with hallucination predisposition

ABSTRACT

Introduction: Auditory verbal hallucinations (AVH) are a core symptom of psychotic disorders such as schizophrenia but are also reported in 10–15% of the general population. Impairments in self-voice recognition are frequently reported in schizophrenia and associated with the severity of AVH, particularly when the self-voice has a negative quality. However, whether self-voice processing is also affected in nonclinical voice hearers remains to be specified.

Methods: Thirty-five nonclinical participants varying in hallucination predisposition based on the Launay-Slade Hallucination Scale, listened to prerecorded words and vocalisations differing in identity (self/other) and emotional quality. In Experiment 1, participants indicated whether words were spoken in their own voice, another voice, or whether they were unsure (recognition task). They were also asked whether pairs of words/vocalisations were uttered by the same or by a different speaker (discrimination task). In Experiment 2, participants judged the emotional quality of the words/vocalisations.

Results: In Experiment 1, hallucination predisposition affected voice discrimination and recognition, irrespective of stimulus valence. Hallucination predisposition did not affect the evaluation of the emotional valence of words/vocalisations (Experiment 2).

Conclusions: These findings suggest that nonclinical participants with high HP experience altered voice identity processing, whereas HP does not affect the perception of vocal emotion. Specific alterations in self-voice perception in clinical and nonclinical voice hearers may establish a core feature of the psychosis continuum.

KEYWORDS:

• Hallucination predisposition
• self
• voice
• discrimination
• recognition

Acknowledgments

The authors gratefully acknowledge all the participants who collaborated in the study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethical standards

The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008.

ORCID

Ana P. Pinheiro http://orcid.org/0000-0002-7981-3682

Magda S. Roberto http://orcid.org/0000-0003-4127-561X

Notes

1. Approximately six percent (6.2%) of non-psychotic individuals with frequent AVH convert to psychosis in a five-years follow-up (Daalman, Diederen, Hoekema, van Lutterveld, & Sommer, 2016).

2. The total score ranges between 0 and 64, with higher scores indicating higher HP.

3. Ethics Committee of Faculdade de Psicologia-Universidade de Lisboa, Lisbon (Portugal).

Additional information

Funding

This work was supported by the Fundação para a Ciência e a Tecnologia [FCT; grant number PTDC/MHC-PCN/0101/2014] and BIAL Foundation (Fundação Bial) [grant number BIAL 238/16] awarded to APP and SAK.