Launay-Slade Hallucination Scale Scores on the X-axis and Number of Top- Down Errors in the Semantic Task on the Y-axis. Using partial correlations, we. Keywords: Launay–Slade Hallucination Scale (LSHS-R); Predisposition to hallucinations; Misattribution of source; Intrusive thoughts The Launay–Slade. The Launay-Slade Hallucination Scale (LSHS-R) (Launay Slade, ; Bentall & Slade, a) is a frequently used measure of predisposition to hallucinations.
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Quality of hallucinatory experiences: differences between a clinical and a non-clinical sample
The experience of hallucinations is a hallmark of psychotic disorders, but they are also present in other psychiatric and medical conditions, and may be reported in nonclinical individuals. Despite the increased number of studies probing the incidence of nonclinical hallucinations, the underlying phenomenological characteristics scald still launya understood. This study aimed to examine the psychometrics proprieties of the Portuguese adaptation of the item Launay-Slade Hallucinations Scale LSHS hallhcination, the phenomenological characteristics of nonclinical hallucinatory experiences in a Portuguese sample, and the relationship between clinical symptoms and hallucination predisposition.
Intrusive or vivid thoughts and sleep-related hallucinations were the most common. Although, fundamentally perceived as positive experiences, all types of hallucinations were described as uncontrollable and dominating.
However, the more pleasant they were perceived, the more controllable they were assessed. In addition, hallucination predisposition was associated with increased clinical symptoms. These results corroborate the lower severity of hallucinations in the general population compared to psychotic individuals.
Launay-Slade Hallucination Scale-Revised (LSHS-R) – Allie: Abbreviation / Long Form Info.
Further, they support an association between clinical symptoms and increased vulnerability to hallucinations. Specifically, increased schizotypal tendencies and negative mood anxiety and depression may be related to sladw psychotic risk. Hallucinations represent one of the most intriguing phenomena e. Hallucinatory experiences, usually defined as slave experiences that occur in the absence of corresponding external sensory stimulation Slade and Bentall,are a clinical manifestation of psychiatric disorders such as schizophrenia Mueser et al.
Even though the experience of hallucinations is considered a hallmark of psychotic disorders e. These findings provided support for a continuum model of psychotic experiences that extends not only across diagnostic categories, but also into the non-clinical general population e.
Three distinct states are thought to represent the phenotypic continuum of psychosis: Of note, nonclinical cases represent the largest proportion of the full continuum van Os et al. Llaunay between clinical and nonclinical psychotic symptoms seem to be quantitative rather than qualitative e.
Indeed, the onset of psychosis is often preceded by an increased frequency of nonclinical psychotic symptoms e. The laaunay of nonclinical hallucinations represents a risk factor for conversion to full psychosis e. Hallucinations may occur in different sensory modalities e. Nonetheless, auditory hallucinations are the most common, especially in patients with schizophrenia David and Busatto, Nonetheless, there are important e.
Particularly, AVHs occur with increased frequency and duration in psychotic compared to nonpsychotic individuals de Leede-Smith and Barkus, Moreover, AVHs are perceived as more uncontrollable and unpleasant in psychotic individuals de Leede-Smith and Barkus, The scwle a little softer than the self-voiceattribution external sourceand location of the hallucinated voice inside the head are the main similarities shared by clinical and nonclinical individuals de Leede-Smith and Barkus, VHs may also occur in a wide range of clinical conditions, such as ophthalmologic diseases, neurologic disorders, toxic and metabolic disorders, and psychiatric disorders e.
Although, visual hallucinations are much less common in nonclinical compared to clinical samples, they seem to be more prevalent than auditory hallucinations in healthy individuals Tien, ; Ohayon, Whereas most of the studies have focused on auditory and visual forms of hallucinations e. Despite their rare frequency, olfactory, gustatory, and tactile hallucinations have been additionally reported in both psychotic Lewandowski et al.
Nonetheless, auditory and visual forms represent the major risk factors for a psychiatric diagnosis Ohayon, ; de Leede-Smith and Barkus, In the last decades, a growing laumay of studies probed the pathophysiological mechanisms underlying the experience of hallucinations in nonclinical samples e. While it is important to consider that nonclinical hallucinations are typically less severe than clinical hallucinations e.
The existing studies have most commonly selected participants from university settings e. Of note, nonclinical individuals with higher LSHS scores were found to share phenomenological, cognitive, neuropsychological, and psychophysiological similarities with psychotic patients with hallucinations Bentall et al.
Items were subsequently rephrased by replacing negatively formulated content with positive content in the first modified version of the scale Bentall and Slade, Aiming to increase response variability, Bentall and Slade also replaced the true-or-false response format with a 5-point Likert scale.
As previous versions of the LSHS did not address visual hallucinatory experiences, subsequent versions by Morrison et al. Although, an exploratory factor analysis of the LSHS has shown that hallucination predisposition is better represented by a multi-factor structure e. Whereas some of these inconsistencies may be accounted for by differences in LSHS versions or response formats, and by differences in the samples clinical and nonclinical examined, study discrepancies were reported even when using the same LSHS version.
Despite the controversy surrounding this topic, there is substantial evidence that all LSHS versions are especially reliable, having adequate psychometric properties e. Moreover, the LSHS is a versatile instrument that can be used to measure hallucination predisposition in both nonclinical e. As such, it was adapted to many languages, including Dutch Aleman et al. The validation and adaptation of the LSHS in different languages represent a cross-cultural validation of the hallucination predisposition construct Hui and Triandis, Note that the adaptation of a scale or survey to a specific language and cultural context requires specific statistical analyses that determine whether the instrument has adequate measurement properties to be used not only in the target population, but also in cross-cultural studies.
Three important indices are considered in the evaluation of the quality of an assessment instrument: The decision to use this LSHS version was motivated by the fact that it comprises items concerning several types of hallucinatory experiences auditory, visual, olfactory, and tactileand a response format that allows measuring additional relevant aspects of these experiences e. In a second step, we sought not only to describe the phenomenological characteristics of nonclinical Portuguese hallucinatory experiences e.
Differences between males and females, which were not tested in the previous adaptations of the scale, were also examined. The analysis of sex differences was motivated by previous evidence demonstrating that women are more commonly affected by nonclinical hallucinations when compared to men Young et al. Consequently, we hypothesized that nonclinical hallucinations would be more prevalent in female relative to male participants.
Moreover, based on previous findings Johns et al. In addition, we aimed to determine the association between LSHS ratings and anxious-depressive symptomatology and schizotypal tendencies. Previous studies have shown that the presence of both anxious-depressive symptomatology and schizotypal tendencies Paulik et al.
Quality of hallucinatory experiences: differences between a clinical and a non-clinical sample
Therefore, we hypothesized that the prevalence of hallucinatory experiences would be higher in individuals reporting more clinical symptoms. Participants were recruited, via email, from several universities located in the north, center and south of Portugal, following a sampling procedure commonly used in prior studies with college students e. Data from the participants who responded to the questionnaire were all included in the data analyses.
At the time participants answered the questionnaire, were students, whereas 26 had recently finished their undergraduate or graduate studies.
Considering the nature of this recruitment method, a specific response rate could not be determined. Informed written consent was obtained for each participant prior to their involvement in the study.
This procedure involves three independent steps. Subsequently, the European Portuguese version was back translated into the original English language by three other subjects who were blind to the original version. Finally, all the translations as well as the original version were reviewed to verify semantic, idiomatic, experiential and conceptual equivalence, and after discussing any potential discrepancies, a consensus was reached regarding the final version of the Portuguese LSHS.
The total score ranges between 0 and 64, with higher scores indicating higher hallucination predisposition. These questions aimed to clarify whether the hallucinatory experiences concerned them personally or not, whether these experiences involved other close persons and past events, and if the hallucinatory experiences occurred during stressful events or under the influence of drugs or alcohol.
In order to collect additional relevant information, hallucination predisposition items were interspersed with several fillers items: All filler items were randomly distributed through the LSHS questionnaire, and responses were provided by using the same scoring scale 5-point Likert scale.
The Portuguese adaptation of the BSI Derogatis and Spencer, ; adapted by Canavarro, was used to examine the presence of psychological distress and psychiatric disorders. Total scores range between 0 and 24 for three subscales Obsessive-Compulsive, Depression, and Anxiety0 and 20 for four subscales Hostility, Phobic Anxiety, Paranoid Ideation, and Psychoticism0 and 16 for one subscale Interpersonal Sensitivityand 0 and 28 for one subscale Somatization. These factors in turn include distinct subscales: Total scores range between 0 and Data were collected from April to February College students were invited via email to participate in a study in which they were asked to respond to a questionnaire about perceptual experiences, by accessing a website in a HTLM format, specifically developed for that purpose.
To encourage survey participation, a voucher was drawn. The online survey began by introducing the goal of the study and providing specific instructions about the questionnaire. Prior to the presentation of the questionnaire, participants were reminded about confidentiality and rights. Those who were interested in participating in the study ensured their participation by providing online informed consent. After providing socio-demographic information age, sex, education levelparticipants were asked to complete the questionnaire.
During the presentation of the questions, items remained at the center of the computer screen until a response was made. Answers were automatically saved after the participants’ selection using the mouse. There was no time limit to complete the questionnaire. Participants were subsequently assigned to one of two groups on the basis of hallucination predisposition by a median split.
To encourage participation, vouchers or course credits were provided. First, psychometric properties of the LSHS Portuguese adaptation were examined by assessing its sensitivity, internal validity and internal consistency, and reliability. A frequency analysis for each item was conducted to determine whether all response categories were represented in this sample sensitivity. The factor structure of the questionnaire was performed through Principal Component Analysis using Varimax rotation internal validity.
Only factors with eigenvalues greater than 1 were retained. Subsequently, three Principal Component Analysis were conducted to determine the best solution for the Portuguese version of the questionnaire: For the forced five- and four-factor solutions, items loading above the established saturation values 0.
The reliability was quantified by measuring the internal consistency of the questionnaire with item-total score correlations correlation of each item with the total of the remaining itemsas well as with Cronbach’s alpha coefficients internal consistency and reliability. Items were considered to have adequate consistency if their item-total correlation fell between 0. Second, descriptive analyses were conducted to describe the phenomenological characteristics of the hallucinatory experiences prevalence, frequency of occurrence, perceived degree of control, and affective content of the hallucinatory experience for each factor and hallcuination each item and other slace aspects related to them whether the hallucinatory experiences concerned participants personally, if they involved relatives or friends, events already experienced and stressful events or difficulties, as well as if they occurred under the influence of drugs or alcohol.
Third, an exploratory data analysis was conducted using the Shapiro—Wilk test, the Kolmogorov—Smirnov test, and measures of skewness and kurtosis. This analysis revealed that data for some of the variables under study prevalence, frequency, valence, and control were not normally distributed.
Nonetheless, a direct comparison of results between nonparametric and parametric tests revealed identical results. In such a case, it sladd been suggested to report the results from parametric tests as they have more statistical power than nonparametric tests Fife-Schaw, Hence, differences between males and females in hallucinatory experiences slwde examined using independent samples t -tests, whereas Pearson correlation coefficients were used to probe the relationship between the affective content of the hallucinatory experiences and the perceived degree of control over the hallucinaiton means for the items tapping into the perceived control over the beginning vs.
Finally, independent samples t -tests were used to probe differences between individuals with high vs. Additionally, the relationship between LSHS and clinical scores was assessed using Pearson hallucinztion coefficients.
Parametric statistical tests were used as the normality assumption was verified.