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1.
Br J Psychiatry ; 224(4): 119-121, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38470304

RESUMO

Felt presence is a widely occurring experience, but remains under-recognised in clinical and research practice. To contribute to a wider recognition of the phenomenon, we aimed to assess the presentation of felt presence in a large population sample (n = 10 447) and explore its relation to key risk factors for psychosis. In our sample 1.6% reported experiencing felt presence in the past month. Felt presence was associated with visual and tactile hallucinations and delusion-like thinking; it was also associated with past occurrence of adverse events, loneliness and poor sleep. The occurrence of felt presence may function as a marker for general hallucination proneness.


Assuntos
Emoções , Transtornos Psicóticos , Humanos , Alucinações/epidemiologia , Transtornos Psicóticos/epidemiologia , Fatores de Risco
2.
Br J Psychol ; 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38041610

RESUMO

As people age, they tend to spend more time indoors, and the colours in their surroundings may significantly impact their mood and overall well-being. However, there is a lack of empirical evidence to provide informed guidance on colour choices, irrespective of age group. To work towards informed choices, we investigated whether the associations between colours and emotions observed in younger individuals also apply to older adults. We recruited 7393 participants, aged between 16 and 88 years and coming from 31 countries. Each participant associated 12 colour terms with 20 emotion concepts and rated the intensity of each associated emotion. Different age groups exhibited highly similar patterns of colour-emotion associations (average similarity coefficient of .97), with subtle yet meaningful age-related differences. Adolescents associated the greatest number but the least positively biased emotions with colours. Older participants associated a smaller number but more intense and more positive emotions with all colour terms, displaying a positivity effect. Age also predicted arousal and power biases, varying by colour. Findings suggest parallels in colour-emotion associations between younger and older adults, with subtle but significant age-related variations. Future studies should next assess whether colour-emotion associations reflect what people actually feel when exposed to colour.

3.
Schizophr Bull ; 49(Suppl_2): S86-S92, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36946526

RESUMO

This workshop summary on natural language processing (NLP) markers for psychosis and other psychiatric disorders presents some of the clinical and research issues that NLP markers might address and some of the activities needed to move in that direction. We propose that the optimal development of NLP markers would occur in the context of research efforts to map out the underlying mechanisms of psychosis and other disorders. In this workshop, we identified some of the challenges to be addressed in developing and implementing NLP markers-based Clinical Decision Support Systems (CDSSs) in psychiatric practice, especially with respect to psychosis. Of note, a CDSS is meant to enhance decision-making by clinicians by providing additional relevant information primarily through software (although CDSSs are not without risks). In psychiatry, a field that relies on subjective clinical ratings that condense rich temporal behavioral information, the inclusion of computational quantitative NLP markers can plausibly lead to operationalized decision models in place of idiosyncratic ones, although ethical issues must always be paramount.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Transtornos Mentais , Transtornos Psicóticos , Humanos , Processamento de Linguagem Natural , Linguística , Transtornos Psicóticos/diagnóstico
4.
Schizophr Bull ; 49(Suppl_2): S172-S182, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36946532

RESUMO

BACKGROUND: Language anomalies are a hallmark feature of schizophrenia-spectrum disorders (SSD). Here, we used network analysis to examine possible differences in syntactic relations between patients with SSD and healthy controls. Moreover, we assessed their relationship with sociodemographic factors, psychotic symptoms, and cognitive functioning, and we evaluated whether the quantification of syntactic network measures has diagnostic value. STUDY DESIGN: Using a semi-structured interview, we collected speech samples from 63 patients with SSD and 63 controls. Per sentence, a syntactic representation (ie, parse tree) was obtained and used as input for network analysis. The resulting syntactic networks were analyzed for 11 local and global network measures, which were compared between groups using multivariate analysis of covariance, considering the effects of age, sex, and education. RESULTS: Patients with SSD and controls significantly differed on most syntactic network measures. Sex had a significant effect on syntactic measures, and there was a significant interaction between sex and group, as the anomalies in syntactic relations were most pronounced in women with SSD. Syntactic measures were correlated with negative symptoms (Positive and Negative Syndrome Scale) and cognition (Brief Assessment of Cognition in Schizophrenia). A random forest classifier based on the best set of network features distinguished patients from controls with 74% cross-validated accuracy. CONCLUSIONS: Examining syntactic relations from a network perspective revealed robust differences between patients with SSD and healthy controls, especially in women. Our results support the validity of linguistic network analysis in SSD and have the potential to be used in combination with other automated language measures as a marker for SSD.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Feminino , Transtornos Psicóticos/psicologia , Idioma , Cognição , Fala
5.
Neuroimage Clin ; 37: 103351, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36805417

RESUMO

Auditory verbal hallucinations (AVH) are frequently associated with psychotic disorders, yet also occur in non-clinical voice-hearers. AVH in this group are similar to those within clinical voice-hearers in terms of several phenomenological aspects, but non-clinical voice-hearers report to have more control over their AVH and attribute less emotional valence to them. These dissimilarities may stem from differences on the neurobiological level, as it is still under debate whether the mechanisms involved in AVH are the same in clinical and non-clinical voice-hearers. In this study, 21 clinical and 21 non-clinical voice-hearers indicated the onset and offsets of AVH during an fMRI scan. Using a method called leading eigenvector dynamics analysis (LEiDA), we examined time-varying dynamics of functional connectivity involved in AVH with a sub-second temporal resolution. We assessed differences between groups, and between hallucination and rest periods in dwell time, switching frequency, probability of occurrence, and transition probabilities of nine recurrent states of functional connectivity with a permutation ANOVA. Deviations in dwell times, switching frequencies, and switch probabilities in the hallucination period indicated more erratic dynamics during this condition regardless of their clinical status. Post-hoc analyses of the dwell times exhibited the most distinct differences between the rest and hallucination condition for the non-clinical sample, suggesting stronger differences between the two conditions in this group. Overall, these findings suggest that the neurobiological mechanisms involved in AVH are similar in clinical and non-clinical individuals.


Assuntos
Transtornos Psicóticos , Voz , Humanos , Alucinações/diagnóstico por imagem , Alucinações/etiologia , Transtornos Psicóticos/complicações , Imageamento por Ressonância Magnética , Probabilidade
6.
Schizophr Bull ; 49(12 Suppl 2): S25-S32, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36840539

RESUMO

BACKGROUND AND HYPOTHESIS: The social deafferentation hypothesis (SDA) has been proposed as an explanatory mechanism of hallucinations, based on the theory that social withdrawal triggers the initial phase of schizophrenia. The current study tests the SDA by assessing how loneliness is associated with different types of hallucinations. Under the SDA, increased loneliness is hypothesized to affect the occurrence of hallucinations that carry social meaning, but not of nonsocial hallucinations. STUDY DESIGN: As part of an online survey, 2038 adolescents and young adults from the general population (median age 21 years; 75% female) filled out the Questionnaire for Psychotic Experiences, and the shortened De Jong Gierveld Loneliness Scale. Binomial logistic regression was used to investigate the effects of loneliness severity on past month prevalence of hallucinations, and on the presence of social versus nonsocial hallucinations. STUDY RESULTS: Loneliness increased the prevalence of hallucinations across modalities in the past month. Moreover, stronger degree of loneliness increased the likelihood of hearing voices or laughter, and of hallucinating being touched. Conversely, loneliness decreased the likelihood of experiencing the nonsocial hallucination of a tingling feeling. As expected, loneliness did not increase the prevalence of experiencing nonsocial hallucinations. Surprisingly, neither was loneliness associated with experiencing felt presence. CONCLUSIONS: Our results are novel in showing that loneliness specifically increases the likelihood of hearing human sounds such as voices or laughter, or feeling a human touch. Hallucinations without social meaning were not more likely to be experienced with increasing loneliness. This forms a confirmation of the SDA.


Assuntos
Solidão , Esquizofrenia , Adulto Jovem , Adolescente , Humanos , Feminino , Adulto , Masculino , Alucinações/epidemiologia , Emoções , Inquéritos e Questionários
7.
Schizophr Bull ; 49(12 Suppl 2): S41-S47, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36840540

RESUMO

BACKGROUND AND HYPOTHESIS: Distress associated with auditory (AH) and visual (VH) hallucinations in the general population was found to be predictive of later need for mental healthcare. It is, therefore, important to understand factors relating to the distress individuals experience from their hallucinations. Hallucinations can easily occur under substance-induced states, but recreational drug use is also known as a self-medication strategy. The current study, therefore, investigated whether recreational drug use by individuals from the general population is associated with the degree of distress experienced from AH and/or VH. STUDY DESIGN: Drug use and distress severity associated with AH (N = 3.041) and/or VH (N = 2.218) were assessed by means of an online survey in the general Dutch population (>14 years of age). STUDY RESULTS: Multiple linear regression revealed that while past month consumption of alcohol was associated with less AH- and VH-related distress, past month cannabis use was associated with more AH- and VH-related distress. Furthermore, past month use of nitrous oxide was associated with more severe VH-related distress. CONCLUSION: Recreational use of alcohol, cannabis, and nitrous oxide may play important differential roles in the degree of distress associated with AH and VH in individuals from the general population. The consumption of these substances could form a potential risk factor for the development of distressing hallucinations or function as a signal marker for their occurrence. Due to the cross-sectional design of the current study, the causal relation between recreational drug use and distressing hallucinations remains to be elucidated.


Assuntos
Óxido Nitroso , Uso Recreativo de Drogas , Humanos , Estudos Transversais , Alucinações
8.
Schizophr Bull ; 49(12 Suppl 2): S13-S24, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36840542

RESUMO

BACKGROUND AND HYPOTHESIS: While literature indicates that culture modulates phenomenological characteristics of hallucinations in schizophrenia-spectrum disorders, little is known about the extent culture modulates these characteristics in nonclinical samples. STUDY DESIGN: We compared lifetime prevalence, age of onset, and phenomenology of hallucinations as assessed with the Questionnaire for Psychotic Experiences between samples of nonclinical participants used from the Netherlands (N = 2999) and Qatar (N = 2999). While participant recruitment differed between the 2 countries, the samples were relatively equal in terms of demographic factors. STUDY RESULTS: Our findings indicate that the lifetime prevalence of tactile and olfactory hallucinations are the same across countries. However, the prevalence of auditory hallucinations (AH) and visual hallucinations (VH) were twice as high in the Dutch sample. The reported age of onset for auditory and tactile hallucinations was younger for the Dutch sample. Findings from the measurement invariance supported cross-cultural comparisons with exception for duration, distress, and insight. Qatar's and Dutch participants reported similar valence and extent of interaction with AH and VH. However, compared to those in the Netherlands, participants from Qatar reported significantly more impact on daily functioning and a higher prevalence of receiving commands from hallucinations in the past week. CONCLUSIONS: While AH and VH were more often reported in the Dutch sample, participants in Qatar generally had higher mean factor scores for past week AH and VH than in the Netherlands. The phenomenology of hallucinations in the Qatar sample was of greater clinical relevance, with potentially important implications for early screening and prevention.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Transtornos Psicóticos/epidemiologia , União Europeia , Comparação Transcultural , Alucinações/diagnóstico , Esquizofrenia/epidemiologia
9.
CNS Neurol Disord Drug Targets ; 22(2): 152-160, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34961469

RESUMO

BACKGROUND: Depression is a debilitating disorder that at present lacks a reliable biomarker to aid in diagnosis and early detection. Recent advances in computational analytic approaches have opened up new avenues in developing such a biomarker by taking advantage of the wealth of information that can be extracted from a person's speech. OBJECTIVE: The current review provides an overview of the latest findings in the rapidly evolving field of computational language analysis for the detection of depression. We cover a wide range of both acoustic and content-related linguistic features, data types (i.e., spoken and written language), and data sources (i.e., lab settings, social media, and smartphone-based). We put special focus on the current methodological advances with regard to feature extraction and computational modeling techniques. Furthermore, we pay attention to potential hurdles in the implementation of automatic speech analysis. CONCLUSION: Depressive speech is characterized by several anomalies, such as lower speech rate, less pitch variability and more self-referential speech. With current computational modeling techniques, such features can be used to detect depression with an accuracy of up to 91%. The performance of the models is optimized when machine learning techniques are implemented that suit the type and amount of data. Recent studies now work towards further optimization and generalizability of the computational language models to detect depression. Finally, privacy and ethical issues are of paramount importance to be addressed when automatic speech analysis techniques are further implemented in, for example, smartphones. Altogether, computational speech analysis is well underway towards becoming an effective diagnostic aid for depression.


Assuntos
Depressão , Fala , Humanos , Depressão/diagnóstico
10.
Schizophr Bull ; 49(Suppl_2): S163-S171, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36305054

RESUMO

BACKGROUND AND HYPOTHESIS: Speech is a promising marker to aid diagnosis of schizophrenia-spectrum disorders, as it reflects symptoms like thought disorder and negative symptoms. Previous approaches made use of different domains of speech for diagnostic classification, including features like coherence (semantic) and form (acoustic). However, an examination of the added value of each domain when combined is lacking as of yet. Here, we investigate the acoustic and semantic domains separately and combined. STUDY DESIGN: Using semi-structured interviews, speech of 94 subjects with schizophrenia-spectrum disorders (SSD) and 73 healthy controls (HC) was recorded. Acoustic features were extracted using a standardized feature-set, and transcribed interviews were used to calculate semantic word similarity using word2vec. Random forest classifiers were trained for each domain. A third classifier was used to combine features from both domains; 10-fold cross-validation was used for each model. RESULTS: The acoustic random forest classifier achieved 81% accuracy classifying SSD and HC, while the semantic domain classifier reached an accuracy of 80%. Joining features from the two domains, the combined classifier reached 85% accuracy, significantly improving on separate domain classifiers. For the combined classifier, top features were fragmented speech from the acoustic domain and variance of similarity from the semantic domain. CONCLUSIONS: Both semantic and acoustic analyses of speech achieved ~80% accuracy in classifying SSD from HC. We replicate earlier findings per domain, additionally showing that combining these features significantly improves classification performance. Feature importance and accuracy in combined classification indicate that the domains measure different, complementing aspects of speech.


Assuntos
Esquizofrenia , Humanos , Esquizofrenia/diagnóstico , Semântica , Aprendizado de Máquina
11.
Schizophr Res ; 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36424288

RESUMO

Religiosity is a multidimensional construct known to influence the occurrence of hallucinations. However, it remains unknown how different religiosity types affect clinically relevant phenomenological features of hallucinations. Therefore, we wished to explore associations between intrinsic and extrinsic (non-organizational and organizational) religiosity and hallucinations severity, distress or impact on daily function in a non-clinical Muslim population. We recruited a representative sample of full-time students at Qatar's only national university via systematic random sampling and administered the Questionnaire of Psychotic Experiences online. The study design was cross-sectional. Using structural equation modeling, we estimated effects of the religiosity types on hallucinations severity, distress or impact on daily function in the past week while accounting for sociodemographic variables, anxiety, depressive symptoms, and, delusions. Extrinsic non-organizational religiosity (ENORG) was associated with experiencing reduced distress or impact on daily function from hallucinations both directly and indirectly through intrinsic religiosity. In contrast, extrinsic non-organizational religiosity (EORG) was associated with increased hallucinations distress or impact albeit only through higher intrinsic religiosity. We found no association between any religiosity types and hallucinations severity. Younger and married participants from lower socio-economic class had comparatively more severe hallucinations and more distress from them. Qatari nationality was positively associated EORG and negatively associated with hallucinations distress or impact. Evidence of differential associations between the religiosity types, socioeconomic and cultural groups, and distress or impact from past week's hallucinations supports the importance of alignment between religious, mental health, and well-being education.

12.
J Psychopathol Clin Sci ; 131(2): 172-181, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35230859

RESUMO

Schizophrenia-spectrum disorders (SSD) are highly heterogeneous in risk factors, symptom characteristics, and disease course outcome. Although speech anomalies have long been recognized as a core symptom of SSD, speech markers are an unexplored source of symptom heterogeneity that may be informative in recognizing relevant subtypes. This study investigated speech heterogeneity and its relation to clinical characteristics in a large sample of patients with SSD and healthy controls. Speech samples were obtained from 142 patients with SSD and 147 healthy controls by means of open-ended interviews. Speech was analyzed using standardized open-source acoustic speech software. Hierarchical clustering was conducted using acoustic speech markers. Symptom severity was rated with the Positive and Negative Syndrome Scale, and cognition was assessed with the Brief Assessment of Cognition for Schizophrenia. Three speech clusters could be distinguished in the patient group that differed regarding speech properties, independent of medication use. One cluster was characterized by mild speech disturbances, while two severely impaired clusters were recognized (fragmented speakers and prolonged pausers). Both clusters with severely impaired speech had more severe cognitive dysfunction than the mildly impaired speakers. Prolonged pausers specifically had difficulties with memory-related tasks. Prolonged pausing, as opposed to fragmented speaking, related to chronic active psychosis and refractory psychotic symptoms. Based on speech clustering, subtypes of patients emerged with distinct disease trajectories, symptomatology, and cognitive functioning. The identification of clinically relevant subgroups within SSD may help to characterize distinct profiles and benefit the tailoring of early intervention and improvement of long-term functional outcome. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Transtornos Cognitivos , Transtornos Psicóticos , Esquizofrenia , Cognição , Transtornos Cognitivos/diagnóstico , Humanos , Transtornos Psicóticos/diagnóstico , Esquizofrenia/diagnóstico , Fala
13.
Sci Rep ; 11(1): 7735, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33833310

RESUMO

Although previous studies reported a link between sleep problems and the occurrence of hallucinations, more detailed information is needed to translate this association into clinical practice. This study investigates sleep quality and its relation to prevalence, type, content, and phenomenology of hallucinations, using an online survey in a large population sample (n = 10,299). Based on community-based cluster analysis, four groups could be distinguished that differed in terms of sleep quality. Our results confirm previous studies in showing that poor sleep is associated with the occurrence of hallucinations, and extend previous results on a number of aspects. First, we show that particularly fragmented sleep relates to the occurrence of hallucinations. Second, we show that this is the case for hallucinations across the auditory, visual, olfactory, and tactile domains. Third, our results show that fragmented sleep not only relates to the occurrence, but also to the content, frequency, duration, and associated distress of hallucinations. Finally, compared to poor sleep, good sleep quality is associated with hallucinations that are less negative and disruptive. We conclude that sleep hygiene measures could have a large positive impact on individuals whose fragmented sleep underlies the occurrence of bothersome hallucinations.


Assuntos
Alucinações , Distúrbios do Início e da Manutenção do Sono/psicologia , Análise por Conglomerados , Feminino , Humanos , Masculino , Inquéritos e Questionários
14.
Curr Opin Psychiatry ; 34(3): 222-227, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33560023

RESUMO

PURPOSE OF REVIEW: Excessive synaptic pruning has first been suggested by Irwin Feinberg (1982) as an important pillar in the pathophysiology in schizophrenia (SCZ). This article reviews recent developments highlighting factors implicated in aberrant synaptic pruning and its contribution to disease onset and emergence of cognitive symptoms in SCZ. Unraveling these factors provides new insights for potential prevention and treatment strategies for psychotic disorders. RECENT FINDINGS: Increased pruning in SCZ was recently confirmed by a positron emission tomography-study employing the novel tracer [11C]UCB-J, demonstrating the consequential loss of synaptic density. Recent evidence supports the contributing role of astrocytes and increased complement-mediated microglial pruning in disease onset and cognitive symptoms in SCZ. Increased microglial pruning is mediated specifically by C4. Furthermore, environmental factors (e.g., infections and stress) can lead to dysbiosis which was recently linked to microglial activation and pruning in SCZ. SUMMARY: Recent findings render the pruning machinery a potential target for early treatment and prevention in individuals at high risk for SCZ. Minocycline can improve cognition in SCZ, probably by reducing excessive pruning. Probiotics might also have beneficial effects on cognition, although recent findings are not encouraging. N-acetyl-cysteine recovers functional connectivity in SCZ both in vitro and in vivo, making it an interesting candidate.


Assuntos
Plasticidade Neuronal , Transtornos Psicóticos/patologia , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia , Adolescente , Cognição , Humanos , Microglia
15.
Cortex ; 136: 1-13, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33450598

RESUMO

Auditory hallucinations, the perception of a sound without a corresponding source, are common in people with hearing impairment. Two forms can be distinguished: simple (i.e., tinnitus) and complex hallucinations (speech and music). Little is known about the precise mechanisms underlying these types of hallucinations. Here we tested the assumption that spontaneous activity in the auditory pathways, following deafferentation, underlies these hallucinations and is related to their phenomenology. By extracting (fractional) Amplitude of Low Frequency Fluctuation [(f)ALFF] scores from resting state fMRI of 18 hearing impaired patients with complex hallucinations (voices or music), 18 hearing impaired patients with simple hallucinations (tinnitus or murmuring), and 20 controls with normal hearing, we investigated differences in spontaneous brain activity between these groups. Spontaneous activity in the anterior and posterior cingulate cortex of hearing-impaired groups was significantly higher than in the controls. The group with complex hallucinations showed elevated activity in the bilateral temporal cortex including Wernicke's area, while spontaneous activity of the group with simple hallucinations was mainly located in the cerebellum. These results suggest a decrease in error monitoring in both hearing-impaired groups. Spontaneous activity of language-related areas only in complex hallucinations suggests that the manifestation of the spontaneous activity represents the phenomenology of the hallucination. The link between cerebellar activity and simple hallucinations, such as tinnitus, is new and may have consequences for treatment.


Assuntos
Córtex Auditivo , Perda Auditiva , Zumbido , Percepção Auditiva , Giro do Cíngulo , Alucinações , Audição , Humanos , Imageamento por Ressonância Magnética
16.
Cortex ; 133: 201-214, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33130426

RESUMO

While functional lateralization of the human brain has been a widely studied topic in the past decades, few studies to date have gone further than investigating lateralization of single, isolated processes. With the present study, we aimed to arrive at a more unified view by investigating lateralization patterns in face and word processing, and associated lower-level visual processing. We tested a large and heterogeneous participant group, and used a number of tasks that had been shown to produce replicable indices of lateralized processing of visual information of different types and complexity. Following Bayesian statistics, group-level analyses showed the expected right hemisphere (RH) lateralization for face, global form, low spatial frequency processing, and spatial attention, and left hemisphere (LH) lateralization for visual word and local feature processing. Compared to right-handed individuals, lateralization patterns of left-handed and especially those who are RH-dominant for language deviated from this 'typical' pattern. Our results support the notion that face and word processes come to be lateralized to homologue areas of the two hemispheres, under influence of the RH- and LH-specializations in global form, local feature, and low and high spatial frequency processing. As such, we present a more unified understanding of lateralized vision, providing evidence for the input asymmetry and causal complementarity principles of lateralized visual information processing. The absence of correlations between spatial attention and lateralization of the other processes supports the notion of their independent lateralization, conform the statistical complementarity principle.


Assuntos
Lateralidade Funcional , Idioma , Teorema de Bayes , Mapeamento Encefálico , Face , Humanos , Imageamento por Ressonância Magnética
17.
Curr Opin Psychiatry ; 33(3): 212-218, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32049766

RESUMO

PURPOSE OF REVIEW: After more than a century of neuroscience research, reproducible, clinically relevant biomarkers for schizophrenia have not yet been established. This article reviews current advances in evaluating the use of language as a diagnostic or prognostic tool in schizophrenia. RECENT FINDINGS: The development of computational linguistic tools to quantify language disturbances is rapidly gaining ground in the field of schizophrenia research. Current applications are the use of semantic space models and acoustic analyses focused on phonetic markers. These features are used in machine learning models to distinguish patients with schizophrenia from healthy controls or to predict conversion to psychosis in high-risk groups, reaching accuracy scores (generally ranging from 80 to 90%) that exceed clinical raters. Other potential applications for a language biomarker in schizophrenia are monitoring of side effects, differential diagnostics and relapse prevention. SUMMARY: Language disturbances are a key feature of schizophrenia. Although in its early stages, the emerging field of research focused on computational linguistics suggests an important role for language analyses in the diagnosis and prognosis of schizophrenia. Spoken language as a biomarker for schizophrenia has important advantages because it can be objectively and reproducibly quantified. Furthermore, language analyses are low-cost, time efficient and noninvasive in nature.


Assuntos
Idioma , Esquizofrenia/diagnóstico , Comportamento Verbal/fisiologia , Biomarcadores , Humanos , Prognóstico
18.
Curr Opin Psychiatry ; 33(3): 206-211, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32040043

RESUMO

PURPOSE OF REVIEW: The association between hallucinations and sensory loss, especially vision- and hearing-impairment, has been firmly established over the past years. The deafferentation theory, a decrease of the threshold for activation in the brain and the consequential imbalance between excitatory and inhibitory brain networks, is hypothesized to underly this relationship. Here we review the studies investigating this theory with a focus on the most recent literature to better understand the contribution of sensory loss to hallucinations. RECENT FINDINGS: A large cross-sectional study has recently confirmed the relationship between auditory impairment and deafferentation. However, the underlying mechanisms of deafferentation are still under debate, with hyperexcitability and deviations in bottom-up and top-down processes being the most likely explanations. Social isolation following sensory impairment increases the risk for hallucinations. Better knowledge and awareness about the contribution of deafferentation and loneliness would benefit diagnosis and treatment of hallucinations. SUMMARY: Studies imply activity in higher order areas, corresponding to the functional mapping of sensory system, and a general state of higher excitability as neurobiological explanation. Auditory deafferentation, tinnitus and other auditory hallucinations, likely lie on a continuum. Social isolation mediates psychotic symptoms in sensory-impaired individuals. Currently, there is no standard treatment for deafferentation hallucinations.


Assuntos
Encéfalo/fisiopatologia , Alucinações/etiologia , Mapeamento Encefálico , Estudos Transversais , Alucinações/fisiopatologia , Humanos , Isolamento Social
19.
Cortex ; 111: 100-126, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30472383

RESUMO

Numerous behavioral studies suggest that the processing of various types of visual stimuli and features may be more efficient in either the left or the right visual field. However, not all of these visual-field asymmetries (VFAs) have been observed consistently. Moreover, it is typically unclear whether a failure to observe a particular VFA can be ascribed to certain characteristics of the participants and stimuli, to a lack of statistical power, or to the actual absence of an effect. To increase our understanding of lateralization of visual information processing, we have taken a rigorous methodological and statistical approach to examine the reproducibility of various previously reported VFAs. We did so by performing (near-)exact replications of nine representative previous studies, aiming for sufficient power to detect the effects of interest, and taking into consideration all relevant dependent variables (reaction times and error rates). Following Bayesian analyses -on our data alone as well as on the combined evidence from the original and replication studies- we find precise and reliable evidence that support VFAs in the processing of faces, emotional expressions, global and local information, words, and in the distribution of spatial attention. In contrast, we find less convincing evidence for VFAs in processing of high and low spatial frequencies. Finally, we find no evidence for VFAs in categorical perception of color and shape oddballs, and in the judgments of categorical and coordinate spatial relations. We discuss our results in the light of their implications for theories of visual lateralization.


Assuntos
Lateralidade Funcional/fisiologia , Campos Visuais/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
20.
Brain Cogn ; 119: 10-16, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28923763

RESUMO

It is often assumed that the human brain processes the global and local properties of visual stimuli in a lateralized fashion, with a left hemisphere (LH) specialization for local detail, and a right hemisphere (RH) specialization for global form. However, the evidence for such global-local lateralization stems predominantly from studies using linguistic stimuli, the processing of which has shown to be LH lateralized in itself. In addition, some studies have reported a reversal of global-local lateralization when using non-linguistic stimuli. Accordingly, it remains unclear whether global-local lateralization may in fact be stimulus-specific. To address this issue, we asked participants to respond to linguistic and non-linguistic stimuli that were presented in the right and left visual fields, allowing for first access by the LH and RH, respectively. The results showed global-RH and local-LH advantages for both stimulus types, but the global lateralization effect was larger for linguistic stimuli. Furthermore, this pattern of results was found to be robust, as it was observed regardless of two other task manipulations. We conclude that the instantiation and direction of global and local lateralization is not stimulus-specific. However, the magnitude of global,-but not local-, lateralization is dependent on stimulus type.


Assuntos
Atenção/fisiologia , Dominância Cerebral/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Leitura , Semântica , Percepção de Tamanho/fisiologia , Campos Visuais/fisiologia , Adolescente , Adulto , Córtex Cerebral/fisiologia , Feminino , Lateralidade Funcional , Humanos , Linguística , Masculino , Adulto Jovem
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