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Consciousness and Cognition Mar 2023Strange face illusions describe a range of visual apparitions that occur when an observer gazes at their image reflected in a mirror or at another person's face in a... (Review)
Review
BACKGROUND
Strange face illusions describe a range of visual apparitions that occur when an observer gazes at their image reflected in a mirror or at another person's face in a dimly lit room. The illusory effects range from mild alterations in colour, or contrast, to the perception of distorted facial features, or new strange faces.The current review critically evaluates studies investigating strange face illusions, their methodological quality, and existing interpretations.
METHOD
Searches conducted using Scopus, PubMed, ScienceDirect and the grey literature until June 2022 identified 21 studies (N = 1,132; healthy participants n = 1,042; clinical participants n = 90) meeting the inclusion criteria (i.e., providing new empirical evidence relating to strange face illusions). The total sample had a mean age of 28.3 years (SD = 10.31) and two thirds (67 %) of participants tested to date are female. Results are reported using the Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) guidelines. The review was preregistered at the Open Science Framework (OSF: https://osf.io/ek48d).
RESULTS
Pooling data across studies, illusory new strange faces are experienced by 58% (95%CI 48 to 68) of nonclinical participants. Study quality as assessed by the Appraisal Tool for Cross-Sectional Studies (AXIS) revealed that 3/21 (14.28%) studies were rated as high, 9/21 (42.86%) as moderate and 9/21 (42.86%) as low quality. Whilst the items relating specifically to reporting quality scored quite highly, those relating to study design and possible biases were lower and more variable. Overall, study quality accounted for 87% of the variance in reporting rates for strange faces, with higher quality being associated with lower illusion rates. The prevalence of illusions was also significantly greater in samples that were older, had higher proportions of female participants and for the interpersonal dyad (IGDT) compared to the mirror gaze paradigm (MGT). The moderating impact of study quality persisted in a multiple meta-regression involving participant age, paradigm type (IGDT vs MGT) and level of feature distortion. Our review point to the importance of reduced light levels, face stimuli and prolonged eye fixation for strange face illusions to emerge.
CONCLUSION
Strange face illusions reliably occur in both mirror-gazing and interpersonal gazing dyad paradigms. Further research of higher quality is required to establish the prevalence and particularly, the mechanisms underpinning strange face illusions.
Topics: Humans; Female; Adult; Male; Illusions; Cross-Sectional Studies; Face; Fixation, Ocular; Dissociative Disorders
PubMed: 36764163
DOI: 10.1016/j.concog.2023.103480 -
Journal of Psychiatric Research Jul 2022Schizophrenia (SZ) is a severe neurodevelopmental spectrum disorder with significant consequences for the individual who is diagnosed and their family, resulting in... (Review)
Review
BACKGROUND
Schizophrenia (SZ) is a severe neurodevelopmental spectrum disorder with significant consequences for the individual who is diagnosed and their family, resulting in notable system-level costs associated with the current methods of treatment. With a complex etiology, this syndrome continues to evade our thorough understanding and invites cautious analysis into how the newest research findings may translate into meaningful interventions. Recent explorations of non-invasive interventions in psychiatry suggest that transcranial alternating current stimulation (tACS) is a safe and potentially promising add-on to the current SZ treatment.
METHODS
We performed a systematic literature search for tACS studies on SZ in three databases - Embase, Pubmed and Medline. The search yielded 29 titles and abstracts, of which 8 met the criteria for inclusion: experimental use of tACS on patients with SZ.
RESULTS
We found 8 publications where findings from tACS were applied on participants with SZ. The most common frequencies used were theta (4.5 Hertz [Hz] and 6 Hz), alpha (10 Hz) and gamma (40 Hz). The main findings resulting from tACS delivery were: (1) decrease in auditory hallucinations; (2) decrease in negative symptoms; (3) cognitive improvement; and, (4) no change.
CONCLUSIONS
This scoping review provides a highlight of current protocols used in tACS studies on SZ, their main findings and limitations, and points towards a direction for new approaches. The wide variety of objectives, protocols and assessments used by researchers demonstrates the diversified nature of research currently used in this field, suggesting the need for a more thorough exploration as results continue to emerge.
Topics: Hallucinations; Humans; Schizophrenia; Transcranial Direct Current Stimulation
PubMed: 35525231
DOI: 10.1016/j.jpsychires.2022.04.036 -
Psychological Medicine Oct 2022Psychotic symptoms, that we defined as delusions or hallucinations, are common in bipolar disorders (BD). This systematic review and meta-analysis aims to synthesise the... (Meta-Analysis)
Meta-Analysis Review
Psychotic symptoms, that we defined as delusions or hallucinations, are common in bipolar disorders (BD). This systematic review and meta-analysis aims to synthesise the literature on both lifetime and point prevalence rates of psychotic symptoms across different BD subtypes, including both BD type I (BDI) and BD type II (BDII). We performed a systematic search of Medline, PsycINFO, Embase and Cochrane Library until 5 August 2021. Fifty-four studies ( = 23 461) of adults with BD met the predefined inclusion criteria for evaluating lifetime prevalence, and 24 studies ( = 6480) for evaluating point prevalence. Quality assessment and assessment of publication bias were performed. Prevalence rates were calculated using random effects meta-analysis, here expressed as percentages with a 95% confidence interval (CI). In studies of at least moderate quality, the pooled lifetime prevalence of psychotic symptoms in BDI was 63% (95% CI 57.5-68) and 22% (95% CI 14-33) in BDII. For BDI inpatients, the pooled lifetime prevalence was 71% (95% CI 61-79). There were no studies of community samples or inpatient BDII. The pooled point prevalence of psychotic symptoms in BDI was 54% (95 CI 41-67). The point prevalence was 57% (95% CI 47-66) in manic episodes and 13% (95% CI 7-23.5) in depressive episodes. There were not enough studies in BDII, BDI depression, mixed episodes and outpatient BDI. The pooled prevalence of psychotic symptoms in BDI may be higher than previously reported. More studies are needed for depressive and mixed episodes and community samples.Prospero registration number: CRD 42017052706.
Topics: Adult; Humans; Bipolar Disorder; Prevalence; Psychotic Disorders; Hallucinations; Mania
PubMed: 36016504
DOI: 10.1017/S003329172200201X -
Neuropsychology Review Dec 2018A review of patients with brain injury showing personal neglect is presented. The aim is to shed light on this aspect of neglect often unresearched or only indirectly...
A review of patients with brain injury showing personal neglect is presented. The aim is to shed light on this aspect of neglect often unresearched or only indirectly investigated, and to discuss recent findings concerning the methods used to assess personal neglect, its neural correlates and its association with the more often explored aspect of extrapersonal neglect. The review was performed using PubMed and PsychInfo databases to search for papers published in the last 123 years (until January 2018). We reviewed 81 papers describing either single or group studies for a total of 2247 patients. The results of this review showed that various aspects of personal neglect are still controversial and outcomes potentially contradictory. Despite the data reported in the present review suggest that personal neglect is more frequently associated with lesions of the right hemisphere, the left hemisphere may also play an important role. Not surprisingly, personal neglect and extrapersonal neglect seem to co-occur. However double dissociations of these two forms of neglect have been reported, and they seem to dissociate both from a functional and an anatomical perspective. More recent interpretations of personal neglect suggest that it may result from a disrupted body representation. The development of reliable psychometric tools with shared diagnostic criteria is essential to identify different degrees of personal neglect for different body parts and to better refine personal neglect in comparison to extrapersonal neglect and disorders related to distortions of personal domain.
Topics: Brain Injuries; Humans; Perceptual Disorders; Stroke
PubMed: 30547412
DOI: 10.1007/s11065-018-9394-4 -
The Cochrane Database of Systematic... May 2018Cystic fibrosis is the most common autosomal recessive disease in white populations, and causes respiratory dysfunction in the majority of individuals. Numerous types of... (Review)
Review
BACKGROUND
Cystic fibrosis is the most common autosomal recessive disease in white populations, and causes respiratory dysfunction in the majority of individuals. Numerous types of respiratory muscle training to improve respiratory function and health-related quality of life in people with cystic fibrosis have been reported in the literature. Hence a systematic review of the literature is needed to establish the effectiveness of respiratory muscle training (either inspiratory or expiratory muscle training) on clinical outcomes in cystic fibrosis. This is an update of a previously published review.
OBJECTIVES
To determine the effectiveness of respiratory muscle training on clinical outcomes in people with cystic fibrosis.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials register comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of most recent search: 17 April 2018.A hand search of the Journal of Cystic Fibrosis and Pediatric Pulmonology was performed, along with an electronic search of online trial databases up until 07 May 2018.
SELECTION CRITERIA
Randomised controlled studies comparing respiratory muscle training with a control group in people with cystic fibrosis.
DATA COLLECTION AND ANALYSIS
Review authors independently selected articles for inclusion, evaluated the methodological quality of the studies, and extracted data. Additional information was sought from trial authors where necessary. The quality of the evidence was assessed using the GRADE system MAIN RESULTS: Authors identified 19 studies, of which nine studies with 202 participants met the review's inclusion criteria. There was wide variation in the methodological and written quality of the included studies. Four of the nine included studies were published as abstracts only and lacking concise details, thus limiting the information available. Seven studies were parallel studies and two of a cross-over design. Respiratory muscle training interventions varied dramatically, with frequency, intensity and duration ranging from thrice weekly to twice daily, 20% to 80% of maximal effort, and 10 to 30 minutes, respectively. Participant numbers ranged from 11 to 39 participants in the included studies; five studies were in adults only and four in a combination of children and adults.No significant improvement was reported in the primary outcome of pulmonary function (forced expiratory volume in one second and forced vital capacity) (very low-quality evidence). Although no change was reported in exercise capacity as assessed by the maximum rate of oxygen use, a 10% improvement in exercise duration was found when working at 60% of maximal effort in one study (n = 20) (very low-quality evidence). In a further study (n = 18), when working at 80% of maximal effort, health-related quality of life improved in the mastery and emotion domains (very low-quality evidence). With regards to the review's secondary outcomes, one study (n = 11) found a significant change in intramural pressure, functional residual capacity and maximal inspiratory pressure following training (low-quality evidence). A further study (n = 22) reported that respiratory muscle endurance was significantly longer in the training group (P < 0.01). No studies reported on any other secondary outcomes. Meta-analyses could not be performed due to a lack of consistency and insufficient detail in reported outcome measures.
AUTHORS' CONCLUSIONS
There is insufficient evidence to suggest whether this intervention is beneficial or not. Healthcare practitioners should consider the use of respiratory muscle training on a case-by-case basis. Further research of reputable methodological quality is needed to determine the effectiveness of respiratory muscle training in people with cystic fibrosis. Researchers should consider the following clinical outcomes in future studies; respiratory muscle function, pulmonary function, exercise capacity, hospital admissions, and health-related quality of life. Sensory-perceptual changes, such as respiratory effort sensation (e.g. rating of perceived breathlessness) and peripheral effort sensation (e.g. rating of perceived exertion) may also help to elucidate mechanisms underpinning the effectiveness of respiratory muscle training.
Topics: Adult; Breathing Exercises; Child; Cystic Fibrosis; Humans; Inhalation; Randomized Controlled Trials as Topic; Respiratory Muscles
PubMed: 29797578
DOI: 10.1002/14651858.CD006112.pub4 -
Children (Basel, Switzerland) Jan 2021This review aims to evaluate the effectiveness of virtual reality-based interventions (VR-based interventions) on cognitive deficits in children with attention deficit... (Review)
Review
This review aims to evaluate the effectiveness of virtual reality-based interventions (VR-based interventions) on cognitive deficits in children with attention deficit hyperactivity disorder (ADHD). A systematic review and meta-analysis were performed according to the PRISMA statement and the Cochrane Handbook guidelines for conducting meta-analyses. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the quality of the evidence. Clinical trials published up to 29 October 2020, were included. The meta-analysis included four studies, with a population of 125 participants with ADHD. The magnitude of the effect was large for omissions (SMD = -1.38; = 0.009), correct hits (SMD = -1.50; = 0.004), and perceptual sensitivity (SMD = -1.07; = 0.01); and moderate for commissions (SMD = -0.62; = 0.002) and reaction time (SMD = -0.67; = 0.03). The use of VR-based interventions for cognitive rehabilitation in children with ADHD is limited. The results showed that VR-based interventions are more effective in improving sustained attention. Improvements were observed in attentional vigilance measures, increasing the number of correct responses and decreasing the number of errors of omission. No improvements were observed in impulsivity responses.
PubMed: 33494272
DOI: 10.3390/children8020070 -
Annals of Physical and Rehabilitation... Jul 2021Although previous narrative reviews have highlighted a potential association between visuospatial neglect (VSN) and balance disorders, to what extent different areas of... (Review)
Review
BACKGROUND
Although previous narrative reviews have highlighted a potential association between visuospatial neglect (VSN) and balance disorders, to what extent different areas of balance and mobility could be affected is still unclear.
OBJECTIVES
This systematic review updates previous literature findings and systematically reviews sitting balance, standing balance and mobility outcomes.
METHODS
PubMed, Web of Science, ScienceDirect, Naric-Rehabdata, PEDro and the Cochrane Trials Library were systematically searched. Methodological quality was assessed by the National Heart, Lung, and Blood Institute Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. The association between VSN and sitting balance, standing balance and mobility (walking, stair climbing/descending and transfers) was investigated.
RESULTS
In total, 48 studies were included (4595 stroke survivors): at least 1319 (29%) showed symptoms of VSN. VSN was associated with less independence during sitting, with an asymmetric posture toward the affected body side. For standing balance, we revealed a significant negative association between VSN and mediolateral stability and weight shifting, whereas only activities of daily living-related VSN was associated with weight-bearing asymmetry during static stance. While walking, patients with VSN laterally deviated from their path. Results were inconclusive regarding other aspects of mobility. The association between VSN and balance/mobility seemed to decrease over time.
CONCLUSIONS
Despite great heterogeneity in results, this study suggests that stroke survivors with VSN show specific deviations in posture and movement in the mediolateral direction. Although the association between VSN and balance/mobility has been extensively investigated, explanatory studies evaluating underlying mechanisms of the frequently present association are lacking. Future studies should address this by combining clinical and instrumented assessment of balance and gait performance, preferably longitudinally to investigate the associations over time.
Topics: Activities of Daily Living; Cross-Sectional Studies; Humans; Perceptual Disorders; Postural Balance; Stroke; Stroke Rehabilitation
PubMed: 33152521
DOI: 10.1016/j.rehab.2020.10.003 -
Developmental Medicine and Child... Apr 2015Visual perception is one of the cognitive functions often impaired in children with cerebral palsy (CP). The aim of this systematic literature review was to assess the... (Review)
Review
AIM
Visual perception is one of the cognitive functions often impaired in children with cerebral palsy (CP). The aim of this systematic literature review was to assess the frequency of visual-perceptual impairment (VPI) and its relationship with patient characteristics.
METHOD
Eligible studies were relevant papers assessing visual perception with five common standardized assessment instruments in children with CP published from January 1990 to August 2011.
RESULTS
Of the 84 studies selected, 15 were retained. In children with CP, the proportion of VPI ranged from 40% to 50% and the mean visual perception quotient from 70 to 90. None of the studies reported a significant influence of CP subtype, IQ level, side of motor impairment, neuro-ophthalmological outcomes, or seizures. The severity of neuroradiological lesions seemed associated with VPI. The influence of prematurity was controversial, but a lower gestational age was more often associated with lower visual motor skills than with decreased visual-perceptual abilities.
INTERPRETATION
The impairment of visual perception in children with CP should be considered a core disorder within the CP syndrome. Further research, including a more systematic approach to neuropsychological testing, is needed to explore the specific impact of CP subgroups and of neuroradiological features on visual-perceptual development.
Topics: Cerebral Palsy; Child; Humans; Perceptual Disorders; Visual Perception
PubMed: 25690117
DOI: 10.1111/dmcn.12687 -
JAMA Psychiatry May 2022A substantial increase in the number of trials examining metacognitive training (MCT) for psychosis necessitates an updated examination of the outcomes associated with... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
A substantial increase in the number of trials examining metacognitive training (MCT) for psychosis necessitates an updated examination of the outcomes associated with MCT.
OBJECTIVES
To review the immediate and sustained associations of MCT with proximal (directly targeted) and distal (indirectly influenced) outcomes and assess treatment- and participant-related moderators to identify the potential factors associated with the expected heterogeneity of effect sizes.
DATA SOURCES
Eleven electronic databases were searched from 2007 to June 3, 2021 (alert until September 10, 2021). Reference lists of earlier meta-analyses and included reports were screened.
STUDY SELECTION
Reports examined MCT and included participants with schizophrenia spectrum and related psychotic disorders (1045 reports identified; 281 assessed). There were no age, sex, gender, race and ethnicity, language, or study design restrictions. Two reviewers performed the selection of studies to be analyzed.
DATA EXTRACTION AND SYNTHESIS
The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline was followed. Data were extracted by 3 reviewers and pooled using random effects models. Hedges g effect sizes were computed. The Mixed-Methods Appraisal tool was used to assess study quality.
MAIN OUTCOMES AND MEASURES
Proximal outcomes were global positive symptoms, delusions, hallucinations, and cognitive biases. Distal outcomes were self-esteem, negative symptoms, quality of life, well-being, and functioning. Immediate and sustained outcomes were examined. Meta-regressions, subgroup, and sensitivity analyses assessed moderators.
RESULTS
This systematic review and meta-analysis included 43 studies (46 reports). Forty reports were synthesized in meta-analysis (N=1816 participants) and 6 reports were included in narrative review. In the studies examined, MCT was associated with positive symptoms (g = 0.50; 95% CI, 0.34-0.67), delusions (g = 0.69; 95% CI, 0.45-0.93), hallucinations (g = 0.26; 95% CI, 0.11-0.40), cognitive biases (g = 0.16; 95% CI, 0.03-0.29), self-esteem (g = 0.17; 95% CI, 0.03-0.31), negative symptoms (g = 0.23; 95% CI, 0.10-0.37), and functioning (g = 0.41; 95% CI, 0.12-0.69). These associations were maintained up to 1 year. The quality of life effect size was nonsignificant (g = 0.20; 95% CI, -0.07 to 0.47); only 1 study assessed well-being. Publication year was associated with moderated hallucinations (β = 0.04; 95% CI, 0.00-0.07). Overall, narrative review results corroborated meta-analytic findings.
CONCLUSIONS AND RELEVANCE
In this meta-analysis, MCT for psychosis was associated with benefits up to 1 year postintervention in several treatment contexts. These findings suggest that MCT may merit integration in treatment guidelines for schizophrenia.
Topics: Hallucinations; Humans; Metacognition; Psychotic Disorders; Quality of Life; Schizophrenia
PubMed: 35320347
DOI: 10.1001/jamapsychiatry.2022.0277 -
Brain Sciences May 2023The concept of anomalous self-experience, also termed Self-Disorder, has attracted both clinical and research interest, as empirical studies suggest such experiences... (Review)
Review
Towards a Neurophenomenological Understanding of Self-Disorder in Schizophrenia Spectrum Disorders: A Systematic Review and Synthesis of Anatomical, Physiological, and Neurocognitive Findings.
The concept of anomalous self-experience, also termed Self-Disorder, has attracted both clinical and research interest, as empirical studies suggest such experiences specifically aggregate in and are a core feature of schizophrenia spectrum disorders. A comprehensive neurophenomenological understanding of Self-Disorder may improve diagnostic and therapeutic practice. This systematic review aims to evaluate anatomical, physiological, and neurocognitive correlates of Self-Disorder (SD), considered a core feature of Schizophrenia Spectrum Disorders (SSDs), towards developing a neurophenomenological understanding. A search of the PubMed database retrieved 285 articles, which were evaluated for inclusion using PRISMA guidelines. Non-experimental studies, studies with no validated measure of Self-Disorder, or those with no physiological variable were excluded. In total, 21 articles were included in the review. Findings may be interpreted in the context of triple-network theory and support a core dysfunction of signal integration within two anatomical components of the Salience Network (SN), the anterior insula and dorsal anterior cingulate cortex, which may mediate connectivity across both the Default Mode Network (DMN) and Fronto-Parietal Network (FPN). We propose a theoretical Triple-Network Model of Self-Disorder characterized by increased connectivity between the Salience Network (SN) and the DMN, increased connectivity between the SN and FPN, decreased connectivity between the DMN and FPN, and increased connectivity within both the DMN and FPN. We go on to describe translational opportunities for clinical practice and provide suggestions for future research.
PubMed: 37371325
DOI: 10.3390/brainsci13060845