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Psychiatria Danubina 2020Schizophrenia is a multifactorial neurodevelopmental disorder associated with cognitive dysfunction and changes in primary sensory processing. This article aims to... (Review)
Review
BACKGROUND
Schizophrenia is a multifactorial neurodevelopmental disorder associated with cognitive dysfunction and changes in primary sensory processing. This article aims to explore the current insights into the relationship between schizophrenia and different visual disturbances.
METHODS
To provide a literature review of visual impairments in schizophrenia, we performed a PubMed/MEDLINE and Scopus search to identify all articles in English on the topic up to the end of 2018.
RESULTS
Multiple retinal functional and structural abnormalities are found in patients with schizophrenia. Wider retinal venules suggest chronically insufficient brain supply of oxygen and this could contribute to the occurrence of psychotic symptoms. Optical coherence tomography studies showed that retinal nerve fiber layer, macular thickness, and macular volume were significantly lowered in the chronic phase of schizophrenia. Results from electroretinogram recordings have demonstrated different declinations such as abnormalities of a - wave activity in the photoreceptors or b - wave activity in the bipolar and Muller cells. Abnormalities in eye movements, such as a notable decrease in saccades and smooth pursuit eye movements, are one of the most reliable and reproducible impairments associated with schizophrenia. Disrupted visual processing of the magnocellular pathway may result in a decrease of contrast sensitivity, sensory processing, orientation discrimination, visual integration, trajectory and spatial localization, backward masking and motion tracking. Visual perceptual abnormalities occur in more than 60% of schizophrenic patients and these are visual hallucinations, perceptual distortion of colors, shapes and light intensity, decrease in contour integration and surround suppression. Other, frequently present eye disorders include impaired visual acuity, strabismus and nystagmus.
CONCLUSION
Visual impairments are one of the most important features of schizophrenia, which could help in defining the disease state and assigning appropriate treatment.
Topics: Eye Diseases; Hallucinations; Humans; Psychotic Disorders; Pursuit, Smooth; Saccades; Schizophrenia; Visual Perception
PubMed: 32303031
DOI: 10.24869/psyd.2020.60 -
Journal of Eating Disorders 2013Body image disturbance is a core feature of anorexia nervosa (AN). Attitudinal and cognitive biases as well as fundamental perceptual differences have been hypothesized...
BACKGROUND
Body image disturbance is a core feature of anorexia nervosa (AN). Attitudinal and cognitive biases as well as fundamental perceptual differences have been hypothesized to play a role in this disturbance.
METHOD
This study investigated body image dissatisfaction and distortion, haptic perception and perfectionism in 30 patients with AN and 31 age-matched healthy controls. Participants completed perceptual tasks and self-report measures.
RESULTS
As predicted, participants with AN scored significantly higher on body dissatisfaction, perfectionism measures and had greater body distortion (as assessed by a body size estimation task). Cognitive-affective factors and perfectionism were highly correlated with body image distortion in AN. No significant differences were found between groups on the generic perception task.
CONCLUSIONS
Findings did not confirm the hypothesis of fundamental perceptual inefficiencies in body image disturbance in individuals with AN. Despite renewed interest in fundamental perceptual factors implicated in body image disturbance, these findings suggest that it continues to be important to focus treatment on cognitive affective biases versus fundamental perceptual inefficiencies.
PubMed: 24999398
DOI: 10.1186/2050-2974-1-17 -
Vision Research Apr 2019Our capability of recognizing facial expressions of emotion under different viewing conditions implies the existence of an invariant expression representation. As...
Our capability of recognizing facial expressions of emotion under different viewing conditions implies the existence of an invariant expression representation. As natural visual signals are often distorted and our perceptual strategy changes with external noise level, it is essential to understand how expression perception is susceptible to face distortion and whether the same facial cues are used to process high- and low-quality face images. We systematically manipulated face image resolution (experiment 1) and blur (experiment 2), and measured participants' expression categorization accuracy, perceived expression intensity and associated gaze patterns. Our analysis revealed a reasonable tolerance to face distortion in expression perception. Reducing image resolution up to 48 × 64 pixels or increasing image blur up to 15 cycles/image had little impact on expression assessment and associated gaze behaviour. Further distortion led to decreased expression categorization accuracy and intensity rating, increased reaction time and fixation duration, and stronger central fixation bias which was not driven by distortion-induced changes in local image saliency. Interestingly, the observed distortion effects were expression-dependent with less deterioration impact on happy and surprise expressions, suggesting this distortion-invariant facial expression perception might be achieved through the categorical model involving a non-linear configural combination of local facial features.
Topics: Adolescent; Adult; Analysis of Variance; Cues; Emotions; Facial Expression; Facial Recognition; Female; Fixation, Ocular; Humans; Male; Photic Stimulation; Reaction Time; Recognition, Psychology; Young Adult
PubMed: 29496513
DOI: 10.1016/j.visres.2018.02.001 -
Oncology (Williston Park, N.Y.) Jan 2001The optimal management of opioid-related side effects is hampered by a lack of comparative studies of management strategies. The prevalence of such side effects is... (Comparative Study)
Comparative Study Review
The optimal management of opioid-related side effects is hampered by a lack of comparative studies of management strategies. The prevalence of such side effects is influenced by the extent of disease, the patient's age, the presence of coexistent renal and hepatic disease, pulmonary disease, and cognitive dysfunction, a prior opioid history, use of polypharmacy, dose of opioid drug being administered, and the route of administration. The most common opioid-related side effects are constipation, sedation, nausea, vomiting, and cognitive disturbance. Less frequent side effects include urinary retention, perceptual distortion, respiratory depression, and myoclonus. In an era emphasizing quality of life in cancer care, clinicians need to be aware of (1) factors that influence the prevalence of opioid-related side effects, (2) effective management strategies, and (3) how to recognize when symptoms are opioid related as opposed to caused by other etiologies, such as the patient's disease process or treatment approaches. The use of validated instruments and repeated assessment enhances such an evaluation and subsequent treatment. This article delineates the current optimal management of opioid-related nausea and vomiting, constipation, cognitive side effects, myoclonus, and respiratory depression.
Topics: Analgesics, Opioid; Antiemetics; Antipsychotic Agents; Cathartics; Constipation; Humans; Nausea; Neurobehavioral Manifestations; Receptors, Opioid; Risk Assessment; Vomiting
PubMed: 11271983
DOI: No ID Found -
The Annals of Otology, Rhinology, and... May 2024Chronic rhinosinusitis and related rhinologic disorders are common in routine otolaryngologic practice. Common presenting symptoms include nasal obstruction, facial...
OBJECTIVES
Chronic rhinosinusitis and related rhinologic disorders are common in routine otolaryngologic practice. Common presenting symptoms include nasal obstruction, facial pain, facial pressure, headache, and a subjective feeling of the face feeling "swollen," a perceptual distortion. No validated scale exists to assess facial pain in addition to perceptual distortion or headache. The objective was to develop a novel scale for assessment of facial symptoms experienced by patients presenting for rhinologic evaluation.
METHODS
This was a prospective validation cross-sectional study. A patient questionnaire, the 12-item Facial Complaints Evaluation Scale (FaCES-12), was created to evaluate facial symptoms based on clinical experience and the literature, including severity and timing of facial pain, facial pressure, facial perceptual swelling, and headache. Each item was assessed utilizing an 11-point Likert scale ranging from 0 to 10 in severity. Data was collected prospectively from 210 patients in 1 private and 2 academic otolaryngologic practices from August to December 2019 along with the PROMIS Pain Intensity Scale 3a and 22-Item Sino-nasal Outcome Test. Construct validity was determined using Pearson correlation and exploratory factor analysis. Internal consistency and test-retest reliability were assessed by calculating Cronbach's alpha and assessing test-retest scores.
RESULTS
A new 12-item scale named FaCES-12 was developed. FaCES-12 demonstrated high reliability with a Cronbach's alpha of .94 and high test-retest reliability ( = .90). The scale revealed very strong correlation with the PROMIS Pain Intensity Scale 3a ( = .81) and moderate correlation with the Sino-nasal Outcome Test ( = .48). Exploratory factor analysis demonstrated the scale contained interrelated variables that measured unique components of facial sensations.
CONCLUSION
The FaCES-12 is a valid and reliable instrument for use in the evaluation of facial symptoms. Further research into the application of this scale is warranted.
Topics: Humans; Reproducibility of Results; Cross-Sectional Studies; Sinusitis; Headache; Facial Pain; Surveys and Questionnaires; Psychometrics
PubMed: 38380629
DOI: 10.1177/00034894241233034 -
Frontiers in Psychiatry 2018Going without sleep for long periods of time can produce a range of experiences, including perceptual distortions and hallucinations. Many questions, however, remain... (Review)
Review
Going without sleep for long periods of time can produce a range of experiences, including perceptual distortions and hallucinations. Many questions, however, remain unanswered regarding the types of symptoms which are most reliably elicited, the time of symptom onset, and whether symptoms worsen over time toward psychotic decompensation. Since sleep deprivation exceeding 48 h is considered unethical today, an examination of historical studies with extreme sleep-loss duration is needed to obtain information about what happens during prolonged sleep loss. A systematic-review approach was used to identify experimental and observational studies of sleep deprivation in healthy people which describe the effects of prolonged sleep loss on psychopathological symptoms, without any date restriction. A total of 476 articles were identified. Of these, 21 were eligible for inclusion. Duration of sleep loss ranged between 24 h and 11 nights (total 760 participants; average 72-92 h without sleep). All studies except one reported perceptual changes, including visual distortions (i.e., metamorphopsias), illusions, somatosensory changes and, in some cases, frank hallucinations. The visual modality was the most consistently affected (in 90% of the studies), followed by the somatosensory (52%) and auditory (33%) modalities. Symptoms rapidly developed after one night without sleep, progressing in an almost fixed time-dependent way. Perceptual distortions, anxiety, irritability, depersonalization, and temporal disorientation started within 24-48 h of sleep loss, followed by complex hallucinations and disordered thinking after 48-90 h, and delusions after 72 h, after which time the clinical picture resembled that of acute psychosis or toxic delirium. By the third day without sleep, hallucinations in all three sensory modalities were reported. A period of normal sleep served to resolve psychotic symptoms in many-although not all-cases. Psychotic symptoms develop with increasing time awake, from simple visual/somatosensory misperceptions to hallucinations and delusions, ending in a condition resembling acute psychosis. These experiences are likely to resolve after a period of sleep, although more information is required to identify factors which can contribute to the prevention of persistent symptoms.
PubMed: 30042701
DOI: 10.3389/fpsyt.2018.00303 -
Human Brain Mapping Aug 2019The knowledge of the size of our own body parts is essential for accurately moving in space and efficiently interact with objects. A distorted perceptual representation...
The knowledge of the size of our own body parts is essential for accurately moving in space and efficiently interact with objects. A distorted perceptual representation of the body size often represents a core diagnostic criterion for some psychopathological conditions. The metric representation of the body was shown to depend on somatosensory afferences: local deafferentation indeed causes a perceptual distortion of the size of the anesthetized body part. A specular effect can be induced by altering the cortical map of body parts in the primary somatosensory cortex. Indeed, the present study demonstrates, in healthy adult participants, that repetitive Transcranial Magnetic Stimulation to the somatosensory cortical map of the hand in both hemispheres causes a perceptual distortion (i.e., an overestimation) of the size of the participants' own hand (Experiments 1-3), which does not involve other body parts (i.e., the foot, Experiment 2). Instead, the stimulation of the inferior parietal lobule of both hemispheres does not affect the perception of the own body size (Experiment 4). These results highlight the role of the primary somatosensory cortex in the building up and updating of the metric of body parts: somatosensory cortical activity not only shapes our somatosensation, it also affects how we perceive the dimension of our body.
Topics: Adult; Body Size; Choice Behavior; Female; Functional Laterality; Hand; Humans; Magnetic Resonance Imaging; Male; Photic Stimulation; Somatosensory Cortex; Young Adult
PubMed: 31056809
DOI: 10.1002/hbm.24614 -
Schizophrenia Bulletin Jan 2016The Community Assessment of Psychic Experiences (CAPE) has been used extensively as a measurement for psychosis proneness in clinical and research settings. However, no... (Meta-Analysis)
Meta-Analysis Review
The Community Assessment of Psychic Experiences (CAPE) has been used extensively as a measurement for psychosis proneness in clinical and research settings. However, no prior review and meta-analysis have comprehensively examined psychometric properties (reliability and validity) of CAPE scores across different studies. To study CAPE's internal reliability--ie, how well scale items correlate with one another--111 studies were reviewed. Of these, 18 reported unique internal reliability coefficients using data at hand, which were aggregated in a meta-analysis. Furthermore, to confirm the number and nature of factors tapped by CAPE, 17 factor analytic studies were reviewed and subjected to meta-analysis in cases of discrepancy. Results suggested that CAPE scores were psychometrically reliable--ie, scores obtained could be attributed to true score variance. Our review of factor analytic studies supported a 3-factor model for CAPE consisting of "Positive", "Negative", and "Depressive" subscales; and a tripartite structure for the Negative dimension consisting of "Social withdrawal", "Affective flattening", and "Avolition" subdimensions. Meta-analysis of factor analytic studies of the Positive dimension revealed a tridimensional structure consisting of "Bizarre experiences", "Delusional ideations", and "Perceptual anomalies". Information on reliability and validity of CAPE scores is important for ensuring accurate measurement of the psychosis proneness phenotype, which in turn facilitates early detection and intervention for psychotic disorders. Apart from enhancing the understanding of psychometric properties of CAPE scores, our review revealed questionable reporting practices possibly reflecting insufficient understanding regarding the significance of psychometric properties. We recommend increased focus on psychometrics in psychology programmes and clinical journals.
Topics: Delusions; Factor Analysis, Statistical; Hallucinations; Humans; Perceptual Distortion; Psychometrics; Psychotic Disorders; Reproducibility of Results; Surveys and Questionnaires
PubMed: 26150674
DOI: 10.1093/schbul/sbv088 -
Journal of Affective Disorders Dec 2000Contrary to self-reports, most patients with chronic anxiety disorders exhibit increased muscle tension but not autonomic hyperarousal when at rest. Under everyday... (Review)
Review
Contrary to self-reports, most patients with chronic anxiety disorders exhibit increased muscle tension but not autonomic hyperarousal when at rest. Under everyday stress they tend to react with less physiological flexibility than normal controls. However, they overreact subjectively and physiologically to stimuli that are anxiety-provoking. Diminished physiological flexibility may be either a constitutional trait in anxious individuals, a partial but inadequate adaptation to prolonged stress or the result of a disregard for stressors that are not related to psychopathology. The effects of diminished physiological flexibility on general health are not known. There is only a weak relationship, and in some instances a desynchrony, between physiological changes and perception of change under stress. The inconsistencies between self-reports of physiological states and physiological recordings can be explained by alterations of body sensations through psychological factors, predominantly expectations and attention to bodily states, that lead to perceptual distortions.
Topics: Adaptation, Psychological; Anxiety Disorders; Arousal; Attention; Humans; Perceptual Distortion; Somatoform Disorders
PubMed: 11163423
DOI: 10.1016/s0165-0327(00)00339-6 -
Cognition Jul 2016The fundamental goal of perception is to aid in the achievement of behavioral objectives. This requires extracting and communicating useful information from noisy and...
The fundamental goal of perception is to aid in the achievement of behavioral objectives. This requires extracting and communicating useful information from noisy and uncertain sensory signals. At the same time, given the complexity of sensory information and the limitations of biological information processing, it is necessary that some information must be lost or discarded in the act of perception. Under these circumstances, what constitutes an 'optimal' perceptual system? This paper describes the mathematical framework of rate-distortion theory as the optimal solution to the problem of minimizing the costs of perceptual error subject to strong constraints on the ability to communicate or transmit information. Rate-distortion theory offers a general and principled theoretical framework for developing computational-level models of human perception (Marr, 1982). Models developed in this framework are capable of producing quantitatively precise explanations for human perceptual performance, while yielding new insights regarding the nature and goals of perception. This paper demonstrates the application of rate-distortion theory to two benchmark domains where capacity limits are especially salient in human perception: discrete categorization of stimuli (also known as absolute identification) and visual working memory. A software package written for the R statistical programming language is described that aids in the development of models based on rate-distortion theory.
Topics: Bayes Theorem; Humans; Information Theory; Memory, Short-Term; Models, Psychological; Perception; Psychological Theory; Psychometrics; Visual Perception
PubMed: 27107330
DOI: 10.1016/j.cognition.2016.03.020