Distinguishing multimodal versus multisensory hallucinations in psychosis: Key definitions and a way forward

Cognition in relation to non-auditory or multisensory hallucinations in schizophrenia-spectrum disorders: A scoping review

Multisensory hallucinations refer to unusual perceptual events in the absence of corresponding stimuli, experienced in two or more sensory modalities. Within the schizophrenia-spectrum disorder literature, the cognitive correlates of multisensory and non-auditory hallucinations remain largely unknown. This scoping review aimed to map and synthesise research that explored relationships between cognition and non-auditory and multisensory hallucinations in schizophrenia-spectrum disorders. Published, peer-reviewed, empirical research studies were sought through three databases: Web of Science, Scopus, and PubMed. Studies that had explored visual, olfactory, tactile, and gustatory hallucinations, or multisensory hallucinations, and their relationships to any basic cognitive mechanisms were included. Of 2218 records identified, a total of 17 studies met inclusion criteria. Visual hallucinations were the most frequently explored (13 studies); followed by olfactory hallucinations (five studies), tactile hallucinations (two studies) and multisensory hallucinations (two studies). Several cognitive mechanisms were studied, yet the majority were only explored in individual studies across the sensory modalities, limiting conclusions that could be drawn. Exploring the potential mechanistic drivers for hallucinations across multiple sensory modalities would advance the field significantly and allow for development of aetiological models that better capture the full gamut of hallucinatory experiences.

Visual hallucinations in psychosis: What do people actually see?

BACKGROUND

One in three people with psychosis experience visions. However, little is known about what people see, and current treatments have limited benefits.

OBJECTIVES

To improve the understanding and treatment of visions, this study explored the phenomenology of visions in people with psychosis.

METHODS

Twelve people with psychosis participated in semi-structured interviews. Reflective thematic analysis was used.

RESULTS

Three main themes were generated covering important aspects of phenomenology: 'Content', 'Coherence' and 'Quality'. The first theme 'Content: People see people', demonstrated that the most distressing visions were of people. The second theme 'Coherence: Visions of people who behave like people', captured how visions were coherent with real human behaviour, often by being multimodal experiences that spoke to and touched the observer. The third theme, 'Quality: They look too real' highlighted the compelling sense of authenticity of the visions, making them indistinguishable from reality.

CONCLUSION

Visions represent what we expect to see in everyday life: people, who act and look real. This powerful combination provides insight into the absorbing and all-encompassing nature of visions and their impact on participant's lives. The framework of 'Content', 'Coherence' and 'Quality' provides guidance to support clinicians and researchers to better explore the phenomenology of visions in psychosis.

Hallucinations across sensory domains in people with post-traumatic stress disorder and psychosis

Auditory hallucinations are common in people with histories of adversity, possibly indicating a causal relationship. However, hallucinations occur in multiple sensory modalities and the relationship between trauma and hallucinations in other sensory domains is less explored. We examined the occurrence of hallucinatory experiences in different sensory modalities in people with psychosis who also met criteria for Post-Traumatic Stress Disorder (n = 67). Particular attention was paid to the number of modalities reported and whether the experiences were linked to the person's adversity. This linkage was explored in two ways. First, it was predicted that those people reporting more trauma experiences and symptoms of PTSD would report a greater number of hallucination modalities. Second, we examined if there was content or thematic linkage between the trauma and the hallucinatory experiences. There were high levels of reported auditory (89.6 %), visual (58.2 %) and tactile (46.3 %) hallucinations. Hallucinations in two or more modalities were the norm (71.6 % of the participants). The number of hallucination modalities was moderately associated with a greater number of past traumas and PTSD symptoms. There was a high degree of content and thematic linkage between the trauma and the hallucinations. The linkage between trauma and auditory hallucinations extends to other sensory domains.

Content-based clustering of hallucinations across sensory modalities in a large online survey

Hallucinations can have rather heterogeneous aetiology and presentation. This inspired the concept of different subtypes based on symptom profiles, especially in the field of auditory hallucinations. As many people experience hallucinations in more than one sensory modality, it seems important to investigate potential hallucination subtypes across different sensory modalities. We assessed the content of hallucinations as part of a large survey among the general Dutch population (n = 10,448) using the Questionnaire for Psychotic Experiences. Based on their descriptions, thematic categories were created in a data-driven cluster analysis. 2594 participants who experienced hallucinations over the past week that contained at least 2 different thematic categories were selected. Clustering of their hallucination content was performed with the HDBSCAN method. We identified 4 clusters, i.e., subtypes, which can be typified as 1. hallucinations of foul odors, 2. complex visual scenes, 3. a vast variety of rather common hallucinations possibly related to heightened alertness, and 4. possibly bereavement hallucinations. The bereavement subtype showed an increase in emotional loneliness and the presence of delusions. Our findings suggest that the content of hallucinations can be informative, especially when investigated across sensory modalities. Such subtypes may help to better understand their underlying mechanisms.

The Phenomenology of Visual and Other Nonauditory Hallucinations in Affective and Nonaffective Psychosis: A Mixed Methods Analysis

ABSTRACT

Nonauditory hallucinations in psychosis have not received as much attention relative to voice-hearing experiences. The current paper aimed to document the characteristics of these hallucinations in affective and nonaffective psychosis. Participants were selected from a primary voice-hearing sample, who had endorsed visual, tactile, or olfactory hallucinations ( N = 55-75). A comprehensive, semistructured phenomenological interview was conducted, followed by mixed methods analysis. Visual hallucinations typically occurred daily, for a few minutes per episode, within one's direct line of sight; persons and/or animals were most commonly seen, with low controllability and mostly engendered negative affective outcomes. Tactile and olfactory hallucinations were endorsed by 46.8% and 39.0% of participants, respectively. The affective psychosis group ( n = 33) reported significantly greater awareness and lower functional impairment relative to the nonaffective psychosis group ( n = 42). Qualitative thematic analysis revealed notable themes and subthemes across each of these hallucinations modes. Further phenomenological investigations should be carried out in lesser known hallucination modalities, assisted by the development of appropriate assessment tools.

Emotion regulation flexibility and psychosis: A longitudinal study disentangling components of flexibility in psychosis-proneness

OBJECTIVES

Flexibility in self-regulation has emerged as an important component of mental health. Previous findings found that deficits in two components of regulatory flexibility were linked cross-sectionally to psychosis-proneness. We aimed to replicate and extend these findings longitudinally.

METHODS

We measured psychosis-proneness and components of emotion regulation flexibility (i.e. context sensitivity, repertoire and feedback) at two time points with three months in between.

RESULTS

Two flexibility components predicted psychotic-like experiences. The ability to detect the absence of contextual cues was implicated in both positive and negative dimensions but through opposite pathways. Expressive suppression ability-a subcomponent of repertoire-predicted positive symptoms. None of the flexibility components predicted distress related to the symptoms.

CONCLUSIONS

The current study provides further evidence on the implication of emotion regulation flexibility in the longer-term maintenance of psychotic-like experiences. Future studies can advance this work further by evaluating possible bidirectional relationships between psychotic-like experiences and deficits in emotion regulation flexibility.

Multisensory Hallucinatory Experiences in Migraine: A Preliminary Basis for Olfactory, Somatic-Tactile, and Gustatory Auras

Background and Objectives

Visual auras in migraine have been extensively studied, but less is known about unusual experiences in other sensory domains, including whether they should be diagnostically considered as part of aura symptoms. This study aimed to examine the prevalence of multisensory aura experiences in migraine and their phenomenologic and clinical correlates.

Methods

Respondents were 729 participants with probable migraine, who completed an online study examining unusual sensory experiences. These comprised aura experiences in the auditory, visual, olfactory, somatic-tactile, and gustatory domains. Basic demographic and clinical information and migraine symptomatology were also collected. To facilitate groupwise comparisons, participants with probable migraine were divided into those with and without (visual) aura experiences.

Results

Endorsement of visual aura experiences was the highest (42.1%), whether in a single modality (44.2%) or multiple (55.8%) modalities, followed by somatic-tactile (32.0%), gustatory (21.9%), olfactory (18.6%), and auditory (11.0%) domains. Phenomenologic similarities, for instance, in frequency, personification, and controllability, existed across sensory domains. Somatic-tactile and gustatory auras conversely exhibited greater duration and negative emotional valence. Participants with probable migraine with visual aura tended to report significantly more severe migraine symptoms relative to those with nonvisual or no aura.

Discussion

Our findings provide preliminary indication that unusual olfactory, somatic-tactile, and gustatory experiences in migraine are common and could be clinically significant as aura symptoms. Increased clinician and patient awareness and effective management of these symptoms are essential for a holistic therapeutic approach to migraine.

Exploring the cognitive profiles related to unimodal auditory versus multisensory hallucinations in schizophrenia-spectrum disorders

INTRODUCTION

Hallucinations can be experienced across multiple sensory modalities, but psychiatric studies investigating the cognitive mechanisms of hallucinations have been somewhat restricted to the auditory domain. This study explored the cognitive profiles of individuals experiencing multisensory hallucinations (MH) in schizophrenia-spectrum disorders (SSD) and compared these to those experiencing unimodal auditory hallucinations (AH) or no hallucinations (NH).

METHODS

Participants included SSD patients (n = 119) stratified by current hallucination status (NH, AH, MH) and nonclinical controls (NCs; n = 113). Group performance was compared across several cognitive domains: speed of processing, attention, working memory, verbal learning, visual learning, reasoning and problem-solving, social cognition, and inhibition.

RESULTS

The clinical groups performed worse than NCs but differences between the clinical groups were not evident across most cognitive domains. Exploratory analyses revealed that the MH group was more impaired on the visual learning task compared to the NH (but not AH) group.

CONCLUSIONS

Preliminary results suggest that impaired visual learning may be related to MH. This could be attributed to the presence of visual hallucinations (VH), or greater psychopathology, in this group. However, replication is needed, as well as the investigation of other potential cognitive mechanisms of MH.

Prevalence of multisensory hallucinations in people at risk of transition to psychosis

Hallucinations can occur in single or multiple sensory modalities. Greater attention has been paid to single sensory experiences with a comparative neglect of hallucinations that occur across two or more sensory modalities (multisensory hallucinations). This study explored how common these experiences were in people at risk of transition to psychosis (n=105) and considered whether a greater number of hallucinatory experiences increased delusional ideation and reduced functioning, both of which are associated with a greater risk of transition to psychosis. Participants reported a range of unusual sensory experiences, with two or three being common. However, when a strict definition of hallucinations was applied, in which the experience has the quality of a real perception and in which the person believes them to be real experiences, then multisensory experiences were rare and when reported, single sensory hallucinations in the auditory domain were most common. The number of unusual sensory experiences or hallucinations was not significantly associated with greater delusional ideation or poorer functioning. Theoretical and clinical implications are discussed.

Prevalence and nature of multi-sensory and multi-modal hallucinations in people with first episode psychosis

Hallucinations can occur in single or multiple sensory modalities. This study explored how common these experiences were in people with first episode of psychosis (n = 82). Particular attention was paid to the number of modalities reported and whether the experiences were seen to be linked temporally and thematically. It was predicted that those people reporting a greater number of hallucinations would report more delusional ideation, greater levels of distress generally and lower functioning. All participants reported hallucinations in the auditory domain, given the nature of the recruitment. The participants also reported a range of other unusual sensory experiences, with visual and tactile hallucinations being reported by over half. Moreover, single sensory experiences or unimodal hallucinations were less common than two or more hallucination modalities which was reported by 78% of the participants. The number of hallucinations was significantly associated with greater delusional ideation and higher levels of general distress, but not with reduced functioning. It is clear there is a need to refine psychological treatments so that they are better matched to the actual experiences reported by people with psychosis. Theoretical implications are also considered.

Girl's and women's experiences of seeking mental health support for symptoms associated with psychosis. A narrative review

BACKGROUND

Women are more likely than men to experience symptoms associated with psychosis, such as voice hearing, and more likely to seek mental health support. However, little is known about the emotional experiences of girls and young women who seek help for symptoms of psychosis to inform gender sensitive services and access routes. The current review offers the first focused insights into barriers and facilitators relating to help seeking for girls and women experiencing symptoms of psychosis.

METHODS

OneSearch, PubMed, and PsychINFO databases were searched for suitable papers in relation to the research question between November 2021 and February 2022; 139 papers were found, of which eight met the inclusion criteria for review.

RESULTS

Across the eight papers reviewed, participants were aged 15- to 71-years-old. From the participant numbers available, data from a total of 54,907 participants from a range of demographic groups were included in the review. Results and findings sections from the eight papers were reviewed for themes, and four overarching themes emerged: (1) The emotional cost of seeking help, (2) voice hearing for girls and women, (3) side effects of treatment, and (4) facilitators to accessing support.

DISCUSSION

Engagement in talking therapies can be difficult when services minimize the experience of psychosis-related symptoms. Women may be more likely to have their symptom-related distress diagnosed as a mood disorder, rather than symptoms of psychosis being identified, preventing timely tailored intervention. Normalization, psychoeducation, social support, and validation were recommended as helpful interventions.

How to Promote User Purchase in Metaverse? A Systematic Literature Review on Consumer Behavior Research and Virtual Commerce Application Design

Virtual commerce applies immersive technology such as augmented reality and virtual reality into e-commerce to shift consumer perception from 2D product catalogs to 3D immersive virtual spaces. In virtual commerce, the alignment of application design paradigms and the factors influencing consumer behavior is paramount to promote purchase of products and services. The question of their relation needs to be answered, together with the possible improvement of application design. This paper used a systematic literature review approach to synthesize research on virtual commerce from both application design and consumer behavior research, considering the promotion of purchase in virtual commerce settings. Throughout the review, influential factors to purchase and preeminent design artifacts were identified. Then, the research gaps were discovered by mapping the design artifacts to the influential factors, which can inspire future research opportunities on the synergy of these two research directions. Moreover, the evolution of virtual commerce research along with multiple directions were discussed, including the suggestion of meta-commerce as a future trend.

Exploring multimodal hallucinations and disturbances in the basic and bodily self: A cross-sectional study in a non-clinical sample

The bodily self is key to emotional embodiment, which is important for social functioning and emotion regulation. There is a paucity of research systematically assessing how basic and bodily self-disturbances relate to multimodal hallucinations. This study hypothesised that participants with greater hallucination-proneness would report greater degrees of basic and bodily self-disturbance and would demonstrate more ambiguous and less discrete mapping of emotional embodiment. Stage one screened non-clinical participants' degree of hallucination-proneness. Stage two participants completed seven further questionnaires. Hierarchical linear regression modelled the influence of hallucination-proneness and covariates on measures of basic and bodily self-disturbance and sensed presence. Stage two participants also completed a computerised body mapping task (EmBODY) which assessed emotional embodiment. Topographical maps were generated to compare patterns of embodiment between high and low hallucination-proneness groups. 55 respondents participated in stage two, with 18 participants from the high or low hallucination-proneness groups completing EmBODY. In the hierarchical regression analyses, the addition of a measure of hallucination proneness in the final step only increased predictive power where the dependent variable assessed sensed presence (p = 0.035 and p = 0.009, respectively). The EmBODY data revealed that participants with low hallucination-proneness consistently reported more bodily activation across 14 emotional states, whereas the high hallucination-proneness group reported more deactivation. In conclusion, hallucination-proneness was most strongly associated with sensed presence experiences. Patterns of embodiment appeared similar between the two groups, despite consistent differences in activation and deactivation. These findings are exploratory and need to be confirmed in a larger sample.