Previous studies have proposed two cognitive mechanisms responsible for the Ebbinghaus illusion effect, i.e., contour interaction and size contrast. However, the neural underpinnings of these two mechanisms are largely unexplored. The present study introduced binocular depth to the Ebbinghaus illusion configuration and made the central target appear either in front of or behind the surrounding inducers in order to disturb size contrast instead of contour interaction. The results showed that the illusion effect, though persisted, was significantly reduced under the binocular depth conditions. Notably, the target with a larger perceived size reduced early alpha-band power (8-13 Hz, 0-100 ms after stimulus onset) at centroparietal sites irrespective of the relative depth of the target and the inducers, with the parietal alpha power negatively correlated with the illusion effect. Moreover, the target with a larger perceived size increased the occipito-parietal beta-band power (14-25 Hz, 200-300 ms after stimulus onset) under the no-depth condition, and the beta power was positively correlated with the illusion effect when the depth conditions were subtracted from the no-depth condition. The findings provided neurophysiological evidence in favor of the two cognitive mechanisms of the Ebbinghaus illusion by revealing that early alpha power is associated with low-level contour interaction and late beta power is linked to high-level size contrast, supporting the claim that neural oscillations at distinct frequency bands dynamically support different aspects of visual processing.
Humans ; Alpha Rhythm/physiology* ; Female ; Male ; Size Perception/physiology* ; Young Adult ; Adult ; Beta Rhythm/physiology* ; Photic Stimulation/methods* ; Illusions/physiology* ; Optical Illusions/physiology* ; Depth Perception/physiology*

No abstract available.
Codon ; Hallucinations ; Illusions

During antipsychotic drug treatment, clinicians occasionally encounter sudden attacks of oculogyric crisis (OGC) and/or paroxysmal perceptual alteration (PPA) which occur mostly in the afternoon or early evening lasting for minutes to hours and are eventually remitted with rests or short sleep and/or medications such as benzodiazepines, anticholinergics and so forth. Moreover, these attacks are usually accompanied with psychiatric symptoms such as various modalities of hallucinations and illusions, delusions, obsessive thoughts, panic attacks, agitation as well as autonomic symptoms. These accompanying psychiatric symptoms can be perceived as a worsening of psychiatric symptoms if the clinician does not understand the symptoms due to the side effects of antipsychotic drugs, which may result in increasing the dosage of antipsychotics instead of reducing doses or switching to less offending drugs. On the other hand, patients could easily recognize the symptoms as the adverse effects of drugs. This literature review and case-series study is aimed to raise awareness of OGC and PPA by providing clinical cases and author's views with the literature reviews about concepts, recognitions and managements from the works of Japanese authors who first reported the clinical importance of these attacks, particularly PPA.
Antipsychotic Agents ; Asian Continental Ancestry Group ; Benzodiazepines ; Cholinergic Antagonists ; Delusions ; Dihydroergotamine ; Hallucinations ; Hand ; Humans ; Illusions ; Panic Disorder ; Schizophrenia

PURPOSE: We hypothesized that the central dislocation of the femoral head does generally not occur in transverse acetabular fractures, although it does usually occur in both column fractures. MATERIALS AND METHODS: Fifty-two transverse and both column acetabular fracture cases were evaluated retrospectively. The distances between (a) the sciatic notch on the fracture side and the vertical axis of the pelvis (VA line) and (b) the contralateral intact sciatic notch and the VA line were measured. The a/b ratio corresponded to the superior iliac segment displacement or rotation. The ratio of the distance between the fracture side femoral head and the VA line (c) and the distance between the contralateral intact femoral head and the VA line (d) corresponded to the femoral head displacement. The width of ischium (e) on fractured side and (f) contralateral side were measured. The e/f ratio increment reflected ischiadic fragment mobility. RESULTS: The median value of femoral head displacement (c/d) of the transverse fracture group (n=25) was 1.02 (1.000-1.07). Ischiadic fragment rotation (e/f ratio) of the transverse fracture group was 1.000. The median value of femoral head displacement (c/d) of the both column fractures (n=27) was 0.78 (0.64-0.85). Ischiadic fragment rotation (e/f ratio) of the both-column group was 1.15 (1.06-1.23). The differences between groups according to measurements were statistically significant. CONCLUSION: In contrary to Letournel description, our findings showed no medialization of femoral head in transverse acetabular fractures in general. This might be an illusion resulting from external rotation of the superior iliac segment.
Acetabulum* ; Dislocations* ; Head* ; Hip Dislocation ; Illusions ; Ischium ; Pelvis ; Retrospective Studies

PURPOSE: We hypothesized that the central dislocation of the femoral head does generally not occur in transverse acetabular fractures, although it does usually occur in both column fractures. MATERIALS AND METHODS: Fifty-two transverse and both column acetabular fracture cases were evaluated retrospectively. The distances between (a) the sciatic notch on the fracture side and the vertical axis of the pelvis (VA line) and (b) the contralateral intact sciatic notch and the VA line were measured. The a/b ratio corresponded to the superior iliac segment displacement or rotation. The ratio of the distance between the fracture side femoral head and the VA line (c) and the distance between the contralateral intact femoral head and the VA line (d) corresponded to the femoral head displacement. The width of ischium (e) on fractured side and (f) contralateral side were measured. The e/f ratio increment reflected ischiadic fragment mobility. RESULTS: The median value of femoral head displacement (c/d) of the transverse fracture group (n=25) was 1.02 (1.000-1.07). Ischiadic fragment rotation (e/f ratio) of the transverse fracture group was 1.000. The median value of femoral head displacement (c/d) of the both column fractures (n=27) was 0.78 (0.64-0.85). Ischiadic fragment rotation (e/f ratio) of the both-column group was 1.15 (1.06-1.23). The differences between groups according to measurements were statistically significant. CONCLUSION: In contrary to Letournel description, our findings showed no medialization of femoral head in transverse acetabular fractures in general. This might be an illusion resulting from external rotation of the superior iliac segment.
Acetabulum* ; Dislocations* ; Head* ; Hip Dislocation ; Illusions ; Ischium ; Pelvis ; Retrospective Studies

BACKGROUND AND OBJECTIVES: Vertigo is an illusion of environmental movement due to various causes, thus it is hard for medical doctors to determine the exact kind of dizziness in the final diagnosis. Recently, cervical vertigo was reported from several vertigo cases. Cervical vertigo is defined as sensation of rotation, resulting from an alteration of the neck proprioceptive afferents of the upper cervical spine. The aim of our study is to document the clinical features and the treatment outcomes in vertigo patients with myofascial pain syndrome (MPS). SUBJECTS AND METHOD: A total of 488 patients, excluding 18 patients who received other diagnosis, were examined to investigate the reasons for dizziness. We evaluated 34 patients, who were diagnosed with cervical vertigo by questionnaire after MPS treatments. Clinical evaluations for cervical vertigo were performed on all subjects, and vestibular function tests were also performed in patients with vertigo symptoms. All patients received a total of 4 treatments including trigger point injection, physical therapy or medication, and then followed up, respectively. The symptom changes of dizziness, patient satisfaction and cervical pain were checked before and treatment 1, 2, 4 times by Visual Analogue Scale (VAS) score. RESULTS: There were significant improvement in the VAS score of dizziness, patient satisfaction and cervical pain after treatment for MPS. CONCLUSION: Treatment for MPS could improve dizziness in cervical vertigo with MPS patients, but further study is needed to clearly confirm the cervical vertigo with MPS for improving patient's quality of life.
Diagnosis* ; Dizziness ; Facial Neuralgia ; Humans ; Illusions ; Myofascial Pain Syndromes ; Neck ; Neck Pain ; Patient Satisfaction ; Quality of Life ; Surveys and Questionnaires ; Sensation ; Spine ; Trigger Points ; Vertigo* ; Vestibular Function Tests

PURPOSE: The aims of this study were to develop and test the validity of the Korean Nursing Delirium Scale (Nu-DESC) for older patients in hospital. METHODS: The Korean Nu-DESC was developed based on the Nu-DESC (Gaudreau, 2005), and revised according to nursing records related to signs and symptoms of older patients with delirium (n=361) and the results of a pilot study (n=42) in one general hospital. To test the validity of the Korean Nu-DESC, 75 older patients whom nurses suspected of delirium from 731 older patients from 12 nursing units were assessed by bedside nurses using the Korean Nu-DESC. A Receiver Operating Characteristic Curve of the Korean Nu-DESC was constructed with an accompanying Area Under the Curve (AUC). RESULTS: Specific examples such as irritable, kidding, sleeping tendency, which were observed by bedside nurses in Korea, were identified in the five features of signs and symptoms of delirium in the instrument. The Korean Nu-DESC was psycho-metrically valid and had a sensitivity and specificity of .81-.76 and .97-.73, respectively. The AUC were .89, .74. CONCLUSION: Results of this study indicate that the Korean Nu-DESC is well-suited for widespread clinical use in busy inpatients settings and shows promise as a research instrument.
Aged ; Aged, 80 and over ; Area Under Curve ; Behavior ; Communication ; Confusion ; Delirium/diagnosis/*nursing ; Female ; Hallucinations ; Hospitals, General ; Humans ; Illusions ; Male ; Pilot Projects ; *Program Development ; Psychomotor Performance ; Questionnaires ; ROC Curve ; Republic of Korea ; Translating

The issue of cold damage is one of the major topics of orthodox medicine in East Asia. From the historical view of point, most of the medical practitioners have turned The Theory of Cold Damage to account as their grounds for justifying their own argument. However, it is rare to find a book related to The Theory of Cold Damage in Korea's traditional medicine. Therefore, people have perceived the research status of cold damage is unsatisfactory. This problem could be analyzed by dividing it into a medicinal herb problems and theory problem. First, the medicinal herbs needed for the prescription based on The Theory of Cold Damage don't grow in the Korean Peninsula. Accordingly, there were a lot of restrictions on the free use of these prescriptions. Nevertheless, Chinese medicinal herbs were essential to even the use of the prescriptions besides The Theory of Cold Damage. Accordingly, such aspects do little explain the point that there were few medicine books about The Theory of Cold Damage in Korea. On the other hand, it is hard to exclude the guess that the medical practitioners in the period of the Joseon Dynasty might have presented a theoretically different opinion about cold damage. This study did intensive research on this. As a result of examining the medical practitioners in the latter period of the Joseon Dynasty perceived 'the cold damage to positive and negative meridians' as the case where a patient got attacked by cold as a pathogenic factor in a state of the kidney deficiency. They presented the verdict that kidney deficiency was mostly incurred by sexual relations, and the cold damage to positive and negative meridians broke out when a patient got attacked by cold as a pathogenic factor after having sex. it is an original standpoint shedding light on the relationship between cold damage and the kidney deficiency. The medical practitioners in the latter period of the Joseon Dynasty used Donguibogam as a major text for study on cold damage. In other words, Donguibogam includes the well-organized theory of Yeoksu school who regarded the comparison between internal damage and external damage as important. The medical practitioners in the latter period of the Joseon Dynasty managed to form the theory of the cold damage to positive and negative meridians by deepening the relationship between internal damage and external damage, which was highlighted in Donguibogam. The medical practitioners in the Joseon Dynasty didn't show a big interest in the literature itself, or the so-called The Theory of Cold Damage, which was mainly due to not only the realistic problem of the lack of medicinal herbs needed for applying the prescription to cold damage but also the difference between their positions on cold damage. Therefore, the idea of insufficient research on The Theory of Cold Damage is no more than a kind of optical illusion. On the contrary, we may assume that the medical practitioners in the Joseon Dynasty understood and developed The Theory of Cold Damage in their own way.
Asian Continental Ancestry Group ; Cold Temperature ; Far East ; Hand ; Humans ; Kidney ; Korea ; Light ; Medicine, Traditional ; Meridians ; Optical Illusions ; Plants, Medicinal ; Prescriptions

PURPOSE: The aim of the present study was to evaluate the different features of such instruments and how they cause ocular fatigability. METHODS: Under the same settings and circumstances, 75 participants were asked to read the novel, "You without me?" in different formats including paper book, E-book (biscuit(R), Interpark Inc., LG INNOTECK LTD, Korea) and LCD reader (iPad(R), Apple Inc., United States). For every 10 minutes of reading, 10 minutes of rest was provided. After finishing the novel, the participants were asked to complete a questionnaire, and the data obtained were statistically analyzed using univariate analysis. RESULTS: Compared to paper book readers (1.93), LCD readers (2.40) complained of insufficient lubrication in the eye (p = 0.038), and experience more letter-floating illusions (1.92) than did paper book readers (1.49) (p = 0.043). Moreover, compared to the other formats including the E-book (20%) and paper book (8%), LCD readers (72%) experienced more significant glare symptoms (n = 23) and could read at a faster rate than the other groups of readers (n = 26). CONCLUSIONS: In the present study, the I-Pad caused ocular fatigability more easily than the other formats examined. No statistical significance of ocular discomfort or fatigability was observed among the different format groups. Further investigation with a greater number of age-controlled participants should be conducted prior to designing a study to determine the best format for reading.
Dry Eye Syndromes ; Eye ; Glare ; Illusions ; Lubrication ; Multimedia ; Surveys and Questionnaires

BACKGROUND: Mal de debarquement (MdD) literally means "sickness of disembarkation", and refers to the illusion of movement perceived as an after-effect of traveling on a boat, train, or airplane. The pathophysiology of MdD is currently unknown. CASE REPORT: A 20-year-old man presented with dizziness and swaying sensation for 3 days after a boat trip. Compared with the follow-up EEG without symptoms, the EEG recorded while having MdD symptoms disclosed a significantly decreased alpha-band current source density at the precentral gyrus of the left frontal lobe and increased beta-2 activity at the parahippocampal gyrus of right mesial temporal region. CONCLUSIONS: Our results provide evidence of deranged cortical activity in MdD. To the best of our knowledge this is the first study to document cortical correlates of MdD using an EEG source-localization method.
Aircraft ; Brain ; Dizziness ; Electroencephalography ; Follow-Up Studies ; Frontal Lobe ; Humans ; Illusions ; Magnets ; Motion Sickness ; Parahippocampal Gyrus ; Sensation ; Ships ; Temporal Lobe ; Vertigo ; Young Adult