Hallucination Proneness Research Articles

Psychotic-Like Experiences and Psychological Distress: The Role of Resilience.

The occurrence of psychotic-like experiences and schizotypal features in the general nonclinical population may imply a connection with psychosis-related liability. This study was designed to examine the role of resilience in the relationship of hallucination and delusion-like experiences and schizotypal features to psychological distress in a nonclinical sample. The study sample (n = 432 university students) was selected through a stratified cluster sampling procedure, and measures of hallucination proneness, delusion proneness, schizotypal personality, and psychological distress were administered. While all three indices of psychotic-like experiences correlated with one another, only hallucination proneness and schizotypal personality features correlated with psychological distress and only schizotypal traits correlated with resilience. Schizotypy was found to have an indirect effect on distress through resilience. Findings imply the possibility of two types of schizotypy, with high or low resilience. It appears that schizotypes with low resilience may be susceptible to adversity and mental disorders, while high resilience may be protective.

Dissociation mediates the relationship between childhood maltreatment and subclinical psychosis

ABSTRACTMore than a third of the population report childhood adversity, and these experiences are associated with an increased risk of clinical and subclinical psychosis. The reason why some people go on to develop mental health problems and others do not is a key question for study. It has been hypothesized that dissociative processes mediate the relationship between early adversity and psychosis. The current study assessed whether dissociation, and specifically depersonalization (one component of dissociation), plays a mediating role in the relationship between childhood maltreatment and both hallucination proneness and delusional ideation. The study used a cross-sectional design and recruited a student sample to assess these relationships in a nonclinical group. Dissociation mediated the relationship between early maltreatment and both hallucination proneness and delusional ideation. In terms of specific dissociative processes, depersonalization did not mediate hallucination proneness or delusional ideation. Absorption mediated hallucination proneness; dissociative amnesia (negatively) and absorption mediated delusional ideation. It is likely that dissociation interferes with the encoding of traumatic information in nonclinical as well as clinical groups and in certain ways. Absorption may be particularly relevant. For some people, traumatic memories may intrude into conscious awareness in adulthood as psychotic-type experience.

The prevalence of visual hallucinations in non-affective psychosis, and the role of perception and attention.

Little is known about visual hallucinations (VH) in psychosis. We investigated the prevalence and the role of bottom-up and top-down processing in VH. The prevailing view is that VH are probably related to altered top-down processing, rather than to distorted bottom-up processing. Conversely, VH in Parkinson's disease are associated with impaired visual perception and attention, as proposed by the Perception and Attention Deficit (PAD) model. Auditory hallucinations (AH) in psychosis, however, are thought to be related to increased attention. Our retrospective database study included 1119 patients with non-affective psychosis and 586 controls. The Community Assessment of Psychic Experiences established the VH rate. Scores on visual perception tests [Degraded Facial Affect Recognition (DFAR), Benton Facial Recognition Task] and attention tests [Response Set-shifting Task, Continuous Performance Test-HQ (CPT-HQ)] were compared between 75 VH patients, 706 non-VH patients and 485 non-VH controls. The lifetime VH rate was 37%. The patient groups performed similarly on cognitive tasks; both groups showed worse perception (DFAR) than controls. Non-VH patients showed worse attention (CPT-HQ) than controls, whereas VH patients did not perform differently. We did not find significant VH-related impairments in bottom-up processing or direct top-down alterations. However, the results suggest a relatively spared attentional performance in VH patients, whereas face perception and processing speed were equally impaired in both patient groups relative to controls. This would match better with the increased attention hypothesis than with the PAD model. Our finding that VH frequently co-occur with AH may support an increased attention-induced 'hallucination proneness'.

Expressed Emotion and Hallucination Proneness: The Mediating Role of Metacognitive Beliefs

This study was designed to examine the mediating role of meta-cognitions in the relationship between perceived expressed emotions and hallucination proneness in a non-clinical sample. The study sample (n = 432 university students) was selected through a stratified cluster sampling procedure and measures of perceived expressed emotions, metacognitive beliefs and hallucination proneness were administered. Two dimensions of expressed emotion, perceived irritability and perceived intrusion, and two metacognitive beliefs, beliefs about uncontrollability and danger and beliefs about cognitive confidence were found to be associated with hallucination proneness. However, only negative beliefs about uncontrollability of thoughts mediated the relationship between perceived intrusiveness and hallucination proneness. Findings imply the experience of real or perceived parental intrusiveness may activate negative beliefs about thoughts concerning uncontrollability and danger, which in turn, leads to hallucinatory experiences as a coping strategy and contributes to the persistence of real or perceived career intrusiveness.International Journal of Life Sciences 10 (1) : 2016; 17-24

Maladaptive emotion regulation strategies and stress sensitivity mediate the relation between adverse life events and attenuated positive psychotic symptoms

ABSTRACTIntroduction. There is now solid evidence for a relation between adverse life events (ALE) and psychotic symptoms in patients with psychosis and in the general population. A recent study has shown that this relation may be partially mediated by stress sensitivity, suggesting the influence of other factors. The aim of this study was to assess the mediation effect of emotion regulation strategies and stress sensitivity in the relation between ALE and attenuated positive psychotic symptoms (APPS) in the general population.Methods. Hundred and twelve healthy volunteers were evaluated with measures of APPS, emotion regulation strategies, ALE and stress sensitivity.Results. Results demonstrated that the relation between ALE, hallucination and delusion proneness was completely mediated by maladaptive emotion regulation strategies, but not by stress sensitivity. However, in addition to maladaptive emotion regulation strategies, stress sensitivity demonstrated a mediation effect between ALE and attenuated positive psychotic positive symptoms when positive psychotic symptoms were grouped together.Conclusions. There are probably several possible trajectories leading to the formation of positive psychotic symptoms and the results of the present study reveal that one such trajectory may involve the maladaptive regulation of negative emotions alongside a certain general vulnerability after experiencing ALE.

Dysfunctional meta-cognitive beliefs mediate the relation between temperament traits and hallucination-proneness in non-clinical population

We investigated whether dysfunctional metacognitive beliefs (negative beliefs about uncontrollability and danger of thoughts) mediate the relationship between temperamental characteristics of behavior and hallucinatory-like experiences in healthy subjects (n=137). Our analyses showed that four temperamental traits (emotional reactivity, perseveration, endurance and briskness) were mediated by negative beliefs about uncontrollability and danger of thoughts in relation to hallucination proneness. Our research tentatively suggests that temperament affects hallucination proneness via metacognition.

Hallucinations and inhibitory functioning in healthy young adults with high and low levels of hypomanic personality traits

Introduction. Hallucinations in schizophrenia and hallucination proneness in healthy young adults are associated with a common cognitive mechanism, namely impaired inhibitory control. Hallucinatory-like experiences also seem related to hypomanic symptoms in non-clinical participants; however, the mechanisms involved are unknown. We sought to examine self-reported hallucinatory/anomalous perceptual experiences in students selected for high versus low levels of hypomanic personality traits, and whether hypomania is characterised by deficient inhibitory control.Method. Undergraduate students with either high (n = 26) or low (n = 28) scores on the Hypomanic Personality Scale-Revised (HPS-20) were compared on: (1) the Launay Slade Hallucination Scale-Revised (LSHS-R), a measure of hallucination proneness, (2) the Cardiff Anomalous Perceptions Scale (CAPS) and (3) the Inhibition of Currently Irrelevant Memories (ICIM) task, an index of intentional inhibition.Results. The high HPS group had higher total scores, as well as higher frequency (on CAPS only), intrusiveness and distress (CAPS) scores compared to the low HPS group. They also produced significantly more false alarms on the second run of the ICIM task than the low hypomania traits group.Conclusions. Frequent, intrusive and distressing perceptual anomalies and proneness to hallucinations tend to occur in healthy individuals with hypomanic personality traits and may be associated with transient difficulties with inhibitory control. Inhibitory control may be a cognitive marker of vulnerability to hallucinations across diagnostic boundaries.

Conspiracy theory and cognitive style: a worldview.

This paper assessed whether belief in conspiracy theories was associated with a particularly cognitive style (worldview). The sample comprised 223 volunteers recruited via convenience sampling and included undergraduates, postgraduates, university employees, and alumni. Respondents completed measures assessing a range of cognitive-perceptual factors (schizotypy, delusional ideation, and hallucination proneness) and conspiratorial beliefs (general attitudes toward conspiracist thinking and endorsement of individual conspiracies). Positive symptoms of schizotypy, particularly the cognitive-perceptual factor, correlated positively with conspiracist beliefs. The best predictor of belief in conspiracies was delusional ideation. Consistent with the notion of a coherent conspiratorial mindset, scores across conspiracy measures correlated strongly. Whilst findings supported the view that belief in conspiracies, within the sub-clinical population, was associated with a delusional thinking style, cognitive-perceptual factors in combination accounted for only 32% of the variance.

Predicting psychotic-like experiences during sensory deprivation.

Aims. This study aimed to establish the contribution of hallucination proneness, anxiety, suggestibility, and fantasy proneness to psychotic-like experiences (PLEs) reported during brief sensory deprivation. Method. Twenty-four high and 22 low hallucination-prone participants reported on PLEs occurring during brief sensory deprivation and at baseline. State/trait anxiety, suggestibility, and fantasy proneness were also measured. Results. Both groups experienced a significant increase in PLEs in sensory deprivation. The high hallucination prone group reported more PLEs both at baseline and in sensory deprivation. They also scored significantly higher on measures of state/trait anxiety, suggestibility, and fantasy proneness, though these did not explain the effects of group or condition. Regression analysis found hallucination proneness to be the best predictor of the increase in PLEs, with state anxiety also being a significant predictor. Fantasy proneness and suggestibility were not significant predictors. Conclusion. This study suggests the increase in PLEs reported during sensory deprivation reflects a genuine aberration in perceptual experience, as opposed to increased tendency to make false reports due to suggestibility of fantasy proneness. The study provides further support for the use of sensory deprivation as a safe and effective nonpharmacological model of psychosis.

The hypervigilant misperception of Duchenne smiles in schizotypy

Deficits in the perception of emotion are well documented in schizotypy. In part, individuals with high levels of schizotypy, relative to those with low levels of schizotypy, commit significantly more false-positive errors in perceiving threatening facial emotions. The hypervigilance hallucination hypothesis attempts to link these emotion perception deficits to hallucination proneness in schizotypy. This theory posits that false-perceptual experiences reflect an evolved tendency to commit false-positive errors, in order to avoid the costly consequences associated with false-negative errors. The present study set out to explore the relationship between one aspect of emotion perception – smile perception, and schizotypy factors, as a means of testing the hypervigilance hallucination hypothesis in schizotypy. To these ends, 211 university students (111 females and 100 males, mean age = 19.5 years; SD = 1.61) completed the Schizotypal Personality Questionnaire and a smile recognition task embedded within a signal detection paradigm. A positive correlation was found between schizotypy and false-positive errors, further implicating perceptual sensitivity and response bias in schizotypy, and providing support for the hypervigilance hallucination hypothesis. The relevance of these findings to schizophrenia is discussed.

Psychotic-like experiences and their cognitive appraisal under short-term sensory deprivation.

Aims: This study aimed to establish and compare the effects of brief sensory deprivation on individuals differing in trait hallucination proneness.Method: Eighteen participants selected for high hallucination proneness were compared against 18 participants rating low on this trait. The presence of psychotic-like experiences (PLEs), and participants’ cognitive appraisals of these, was evaluated in three different settings: at baseline, in a “secluded office” environment, and in light-and-sound sensory deprivation.Results: Psychotic-like experiences were experienced significantly more often in sensory deprivation for both groups. In particular, both experienced slight increases in perceptual distortions and anhedonia in seclusion, and these increased further during sensory deprivation. Highly hallucination prone individuals showed a significantly greater increase in perceptual distortions in sensory deprivation than did non-prone individuals suggesting a state-trait interaction. Their appraisals of these anomalous experiences were compared to both clinical and non-clinical individuals experiencing psychotic symptoms in everyday life.Conclusion: Short-term sensory deprivation is a potentially useful paradigm to model psychotic experiences, as it is a non-pharmacological tool for temporarily inducing psychotic-like states and is entirely safe at short duration. Experiences occur more frequently, though not exclusively, in those at putative risk of a psychotic disorder. The appraisals of anomalous experiences arising are largely consistent with previous observations of non-clinical individuals though importantly lacked the general positivity of the latter.

Source retrieval is not properly differentiated from object retrieval in early schizophrenia: an fMRI study using virtual reality.

Source memory, the ability to identify the context in which a memory occurred, is impaired in schizophrenia and has been related to clinical symptoms such as hallucinations. The neurobiological underpinnings of this deficit are not well understood. Twenty-five patients with recent onset schizophrenia (within the first 4.5 years of treatment) and twenty-four healthy controls completed a source memory task. Participants navigated through a 3D virtual city, and had 20 encounters of an object with a person at a place. Functional magnetic resonance imaging was performed during a subsequent forced-choice recognition test. Two objects were presented and participants were asked to either identify which object was seen (new vs. old object recognition), or identify which of the two old objects was associated with either the person or the place being presented (source memory recognition). Source memory was examined by contrasting person or place with object. Both patients and controls demonstrated significant neural activity to source memory relative to object memory, though activity in controls was much more widespread. Group differences were observed in several regions, including the medial parietal and cingulate cortex, lateral frontal lobes and right superior temporal gyrus. Patients with schizophrenia did not differentiate between source and object memory in these regions. Positive correlations with hallucination proneness were observed in the left frontal and right middle temporal cortices and cerebellum. Patients with schizophrenia have a deficit in the neural circuits which facilitate source memory, which may underlie both the deficits in this domain and be related to auditory hallucinations.

Shot through with voices: dissociation mediates the relationship between varieties of inner speech and auditory hallucination proneness.

Inner speech is a commonly experienced but poorly understood phenomenon. The Varieties of Inner Speech Questionnaire (VISQ; McCarthy-Jones & Fernyhough, 2011) assesses four characteristics of inner speech: dialogicality, evaluative/motivational content, condensation, and the presence of other people. Prior findings have linked anxiety and proneness to auditory hallucinations (AH) to these types of inner speech. This study extends that work by examining how inner speech relates to self-esteem and dissociation, and their combined impact upon AH-proneness. 156 students completed the VISQ and measures of self-esteem, dissociation and AH-proneness. Correlational analyses indicated that evaluative inner speech and other people in inner speech were associated with lower self-esteem and greater frequency of dissociative experiences. Dissociation and VISQ scores, but not self-esteem, predicted AH-proneness. Structural equation modelling supported a mediating role for dissociation between specific components of inner speech (evaluative and other people) and AH-proneness. Implications for the development of "hearing voices" are discussed.

Relationship between self-focused attention and mindfulness in people with and without hallucination proneness.

The purpose of this work was to study the relationship between self-focused attention and mindfulness in participants prone to hallucinations and others who were not. A sample of 318 healthy participants, students at the universities of Sevilla and Almería, was given the Launay-Slade Hallucinations Scale-revised (LSHS-R, Bentall & Slade, 1985). Based on this sample, two groups were formed: participants with high (n = 55) and low proneness (n = 28) to hallucinations. Participants with a score higher than a standard deviation from the mean in the LSHS-R were included in the high proneness group, participants with a score lower than a standard deviation from the mean in the LSHR-R were included in the second one. All participants were also given the Self-Absorption Scale (SAS, McKenzie & Hoyle, 2008) and the Southampton Mindfulness Questionnaire (SMQ, Chadwick et al., 2008). The results showed that participants with high hallucination proneness had significantly higher levels of public (t(80) = 6.81, p < .001) and private (t(77) = 7.39, p < .001) self-focused attention and lower levels of mindfulness (t(81) = -4.56, p < .001) than participants in the group with low hallucination proneness. A correlational analysis showed a negative association between self-focused attention (private and public) and mindfulness (r = -0.23, p < .001; r = -0.38, p < .001 respectively). Finally, mindfulness was found to partly mediate between self-focused attention and hallucination proneness. The importance of self-focused attention and mindfulness in understanding the etiology of hallucinations discussed and suggest some approaches to their treatment.

Corrigendum to “The varieties of inner speech: Links between quality of inner speech and psychopathological variables in a sample of young adults” [Consciousness and Cognition 20 (2011) 1586–1593

Since the publication of our article, we have noted two corrections necessary to our paper. First, our Method section did not correctly report the Likert scaling used for two of the questionnaires employed, and should have stated that items on both the five-item ‘predisposition to auditory hallucinations’ and four-item ‘predisposition to visual hallucinations and disturbances’ scales were coded on a four-point Likert scale running from ‘‘never’’ (scored 1) to ‘‘almost always’’ (scored 4), meaning scores on these scales could run from 5–20 and 4–16 respectively. Second, due to an error in our spreadsheet formula for summating visual hallucination (VH) scores, analyses involving total VH scores were incorrect. Analyses which utilised individual VH items, rather than their summed total, including the calculation of Cronbach’s alpha for this variable and the exploratory factor analysis involving this variable, were unaffected, as these were based on correct item-level data. Analyses involving total VH scores changed as follows. The revised mean VH score (SD, range) was 6.44 (2.29, 4–14). Correlations between corrected VH scores and the other study variables, originally displayed in Table 4 of our paper, are reported in the revised Table 4 presented here. As partial correlations between auditory hallucination proneness and other study variables included partialling for VH scores, these were also altered, and are included in our revised Table 4. In terms of changes involving previously non-significant correlations now becoming significant, correlations between VH scores and Dialogic Inner Speech, Evaluative/Motivational Inner Speech, auditory hallucination proneness, and depression, became significant. No previously reported significant correlations became non-significant as a result of these changes. In terms of the multiple linear regression predicting auditory hallucination proneness, depression dropped out as a significant predictor of this variable but VH scores became a significant predictor. In terms of the multiple linear regression predicting VH scores, depression now became a significant predictor. The corrected relevant complete text section of our Results (Section 3.5) is reported below.

Relationship between drug use and psychopathological variables of risk in university students.

Research has been studying the relationships between drug use and the risk of suffering psychopathological disorders. This study analyzed the relationships existing between this use and certain psychotic disorder risk variables: hallucination, schizotypy and cognitive fusion. Several screening questionnaires on drug use (CAGE), a questionnaire on "cognitive fusion" (TAFS), another on hallucination proneness (LSHS-R) and another on schizotypy (O-LIFE-R) were given to a sample of 308 students at the University of Almeria with a mean age of 19.51 years (SD= 2.11). The results found show how cognitive fusion is positively related to use of cannabis and cocaine, the scores on the schizotypy scale correlated positively with use of alcohol and cannabis, and the scores on a hallucination proneness correlated positively to use of cannabis. Regression equations were found that predicted the use of these substances from the variables of vulnerability to suffering from schizophrenia spectrum disorders. The results show an association between drug use and the risk variables studied.

Relationship Between Childhood Trauma, Mindfulness, and Dissociation in Subjects With and Without Hallucination Proneness

The purpose of this study was to examine the relationship between childhood traumas, mindfulness, and dissociation (more specifically, absorption and depersonalization) in healthy subjects with and without hallucination proneness. A sample of 318 subjects was given the Launay-Slade Hallucination Scale–Revised (R. P. Bentall & P. Slade, 1985). From this sample, 2 groups were formed: one with high and the other with low hallucination proneness. Furthermore, all participants were given the Tellegen Absorption Scale (A. Tellegen & G. Atkinson, 1974), the Cambridge Depersonalization Scale (M. Sierra & G. E. Berrios, 2000), the Southampton Mindfulness Questionnaire (P. D. J. Chadwick et al., 2008), and the Trauma Questionnaire (J. R. E. Davidson, D. Hughes, & D. G. Blazer, 1990). The results showed that in the group with high hallucination proneness, there were significantly more subjects with traumatic experiences than in the group with low predisposition, although no significant difference in the mean number of traumatic experiences undergone in childhood was found between the 2 groups, although there was a trend toward significance. A correlation analysis showed a significant negative association between mindfulness on the one hand and absorption and depersonalization on the other. A positive relationship was also found between childhood traumas and absorption and depersonalization. Finally, multiple mediation analysis showed that the absorption and depersonalization variables acted as mediators between childhood traumas and hallucination proneness. We discuss the importance of the relationship between the variables studied and hallucination proneness and suggest some approaches for their treatment.

A relationship between hallucination proneness and character and temperament: A mediating role of meta-cognitive beliefs in a non-clinical sample

We investigated a mediating role of meta-cognitions in the relationship between Cloninger's temperament and character dimensions and hallucination proneness among healthy subjects (n=135). Two character dimensions—self-directedness and self-transcendence—were related to hallucination proneness. Negative beliefs about uncontrollability of thoughts partially mediated the relationship between these two character dimensions and hallucination proneness.

Current perspectives on the mechanisms of auditory hallucinations: introduction to the special research topic

Current perspectives on the mechanisms of auditory hallucinations: introduction to the special research topic

An examination of auditory processing and affective prosody in relatives of patients with auditory hallucinations

Research on auditory verbal hallucinations (AVHs) indicates that AVH schizophrenia patients show greater abnormalities on tasks requiring recognition of affective prosody (AP) than non-AVH patients. Detecting AP requires accurate perception of manipulations in pitch, amplitude and duration. Schizophrenia patients with AVHs also experience difficulty detecting these acoustic manipulations; with a number of theorists speculating that difficulties in pitch, amplitude and duration discrimination underlie AP abnormalities. This study examined whether both AP and these aspects of auditory processing are also impaired in first degree relatives of persons with AVHs. It also examined whether pitch, amplitude and duration discrimination were related to AP, and to hallucination proneness. Unaffected relatives of AVH schizophrenia patients (N = 19) and matched healthy controls (N = 33) were compared using tone discrimination tasks, an AP task, and clinical measures. Relatives were slower at identifying emotions on the AP task (p = 0.002), with secondary analysis showing this was especially so for happy (p = 0.014) and neutral (p = 0.001) sentences. There was a significant interaction effect for pitch between tone deviation level and group (p = 0.019), and relatives performed worse than controls on amplitude discrimination and duration discrimination. AP performance for happy and neutral sentences was significantly correlated with amplitude perception. Lastly, AVH proneness in the entire sample was significantly correlated with pitch discrimination (r = 0.44) and pitch perception was shown to predict AVH proneness in the sample (p = 0.005). These results suggest basic impairments in auditory processing are present in relatives of AVH patients; they potentially underlie processing speed in AP tasks, and predict AVH proneness. This indicates auditory processing deficits may be a core feature of AVHs in schizophrenia, and are worthy of further study as a potential endophenotype for AVHs.