Neural Mechanisms of Voluntary Control Over Hallucinations - Auditory verbal hallucinations (AVH) are among the most distressing symptoms in psychosis, and up to 30% of patients exhibit little to no response to current treatments. This is especially concerning given that the presence of hallucinations alone increases risk of suicide in patients with psychosis. One potential route toward development of new treatments for AVH is based on new evidence that many people with AVH never develop the need to seek treatment, despite the fact that AVH in treatment-seeking and non-treatment-seeking individuals tend to be similar in terms of low-level acoustic qualities such as loudness, duration, and location of voices. One particularly promising predictor comes from the fact that non-treatment-seeking voice-hearing populations consistently endorse a higher degree of control over their experiences than their treatmentseeking counterparts. Perhaps most strikingly, some individuals report an ability to fully control the onset and offset of their voices, which may make the experience of living with these voices significantly less disruptive and distressing. Moreover, new evidence indicates that voluntary inhibition of AVH may be developed in both treatment-seeking and non-treatment-seeking voice-hearers. Understanding the mechanisms specifically driving voluntary control over AVH could lead to new insights into potential treatment strategies to bolster these abilities. We and others have proposed hypotheses for how voluntary control of AVH might arise from cognitive inhibition, alterations in perceptual inference, or interactions between these processes. We propose to identify the mechanisms underlying inhibitory control of hallucinations. We will recruit 102 clinical and non-clinical voice-hearers with a range of control abilities for participation in a set of behavioral, imaging, and electrophysiological tasks designed to identify how voluntary control over voice-hearing occurs. Controlling for key confounds, we will relate our proposed measures to control abilities as measured on the newly-validated Yale Control Over Perceptual Experiences (COPE) Scale. We will also follow a subset of 60 of these participants over two years to identify predictors and correlates of changes in control abilities. To control for presence of hallucinations and psychosis, respectively, we will also recruit 51 matched healthy controls and 51 participants with psychosis but no voice-hearing to participate in the cross-sectional study. Principally, we hypothesize that exertion of control over AVH will result in: 1) activation of separable AVH- and control-related brain networks, the interaction between which will relate to abilities to exert control over AVH; 2) specific alterations in perception as demonstrated by the Conditioned Hallucinations task and EEG measures, corresponding to a decreased precision of perceptual priors, increased perceptual belief updating, or both; and 3) dual-task interference on the Think/No-Think task, an assay of cognitive inhibitory skills. Our goal is to translate the insights gained to new, mechanistically-informed treatments to enhance control over AVH.
