Yvonne M.Y. Han
The Chinese University of Hong Kong
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Featured researches published by Yvonne M.Y. Han.
Clinical Neurophysiology | 2009
Agnes S. Chan; Mei-chun Cheung; Yvonne M.Y. Han; Sophia L. Sze; Winnie W. Leung; Hok Sum Man; Cho Yee To
OBJECTIVE This study examined neurophysiologic activities, executive dysfunctions, and their association in children with Autism Spectrum Disorders (ASD). METHODS Thirty-eight normal and 16 children with ASD participated with parental consent. Executive functions were measured using neuropsychological tests and parent ratings, and neurophysiologic activities were measured using EEG to yield cordance values, an indirect measure of brain perfusion. RESULTS Children with ASD made significantly more intrusion errors and False Alarms on the Hong Kong List Learning Test (HKLLT) and Object Recognition Test (OR) than normal children, but were comparable to normal children on the Rey-Osterrieth Complex Figure Test and Continuous Performance Test. They also showed significantly poorer executive functions in everyday activities as shown on the Behavior Rating Inventory of Executive Function (BRIEF), and had lower frontal perfusion patterns than normal children as shown in the neurophysiologic cordance measures. Frontal cordance values were found to be significantly associated with executive dysfunctions in HKLLT Delayed Intrusions, OR False Alarms and BRIEF. CONCLUSIONS Children with ASD were impaired in everyday executive functioning and response inhibition. The cordance value, which has been shown to correlate with brain perfusion in a number of studies, was significantly correlated with executive dysfunctions. SIGNIFICANCE Exploration of this measure as an index for response to intervention is warranted.
Journal of Affective Disorders | 2012
Agnes S. Chan; Queenie Y. Wong; Sophia L. Sze; Patrick P.K. Kwong; Yvonne M.Y. Han; Mei-chun Cheung
BACKGROUND Given the recent growing interest and encouraging findings in studies of alternative treatments for depression, the present randomized controlled trial study aimed to compare the effect of a newly developed Chinese Chan-based Dejian Mind-Body Intervention (DMBI) with the Cognitive Behavioral Therapy (CBT) on improving depressive symptoms in patients with depression. METHODS Seventy-five participants diagnosed with major depressive disorder were randomly assigned to receive either 10-session CBT or DMBI, or placed on a waitlist. Pre-post measurements included record of anti-depressants treatment, ratings by psychiatrists who were blinded to the experimental design and self-report on mood measures, and performance in a cognitive test tapping concentration ability. RESULTS Both the CBT and DMBI groups demonstrated significantly reduced overall depressive syndrome after intervention at large effect size (0.93-1.10). Furthermore, the DMBI group (p<0.05), but not the CBT or waitlist groups, demonstrated significant reduction in intake of anti-depressants, and significant improvement in specific depression-related symptoms including difficulty in concentration (p=0.002), and problems in gastrointestinal health (p=0.02) and overall sleep quality (p<0.001). LIMITATIONS This study has provided some evidence for the short-term effect of the DMBI on Chinese population. Its long-term effect on a larger sample and on Caucasian population warrants further investigation. CONCLUSIONS The present findings suggest that a Chinese Chan-based Mind-Body intervention has positive effects on improving mood and health conditions of individuals with depression.
Evidence-based Complementary and Alternative Medicine | 2011
Agnes S. Chan; Sophia L. Sze; Mei-chun Cheung; Yvonne M.Y. Han; Winnie W. Leung; Dejian Shi
There has been increasing empirical evidence for the enhancing effects of Dejian Mind-Body Intervention (DMBI), a traditional Chinese Shaolin healing approach, on human frontal brain activity/functions, including patients with autism who are well documented to have frontal lobe problems. This study aims to compare the effects of DMBI with a conventional behavioural/cognitive intervention (CI) on enhancing the executive functions and memory of a nine-year-old boy with low-functioning autism (KY) and to explore possible underlying neural mechanism using EEG theta cordance. At post-one-month DMBI, KYs inhibitory control, cognitive flexibility, and memory functioning have significantly improved from “severely-to-moderately impaired” to “within-normal” range. This improvement was not observed from previous 12-month CI. Furthermore, KY showed increased cordance gradually extending from the anterior to the posterior brain region, suggesting possible neural mechanism underlying his cognitive improvement. These findings have implicated potential applicability of DMBI as a rehabilitation program for patients with severe frontal lobe and/or memory disorders.
The Scientific World Journal | 2012
Agnes S. Chan; Queenie Y. Wong; Sophia L. Sze; Patrick P.K. Kwong; Yvonne M.Y. Han; Mei-chun Cheung
Sleep disturbance is a common problem associated with depression, and cognitive-behavioral therapy (CBT) is a more common behavioral intervention for sleep problems. The present study compares the effect of a newly developed Chinese Chan-based intervention, namely Dejian mind-body intervention (DMBI), with the CBT on improving sleep problems of patients with depression. Seventy-five participants diagnosed with major depressive disorder were randomly assigned to receive 10 weekly sessions of CBT or DMBI, or placed on a waitlist. Measurements included ratings by psychiatrists who were blinded to the experimental design, and a standardized questionnaire on sleep quantity and quality was obtained before and after the 10-week intervention. Results indicated that both the CBT and DMBI groups demonstrated significantly reduced sleep onset latency and wake time after sleep onset (effect size range = 0.46–1.0, P ≤ 0.05) as compared to nonsignificant changes in the waitlist group (P > 0.1). Furthermore, the DMBI group, but not the CBT or waitlist groups, demonstrated significantly reduced psychiatrist ratings on overall sleep problems (effect size = 1.0, P = 0.00) and improved total sleep time (effect size = 0.8, P = 0.05) after treatment. The present findings suggest that a Chinese Chan-based mind-body intervention has positive effects on improving sleep in individuals with depression.
Evidence-based Complementary and Alternative Medicine | 2013
Agnes S. Chan; Yvonne M.Y. Han; Sophia L. Sze; Queenie Y. Wong; Mei-chun Cheung
Our previous studies have reported the therapeutic effects of 10-session Chinese Chan-based Dejian mind-body interventions (DMBI) in reducing the intake of antidepressants, improving depressive symptoms, and enhancing the attentional abilities of patients with depression. This study aims to explore the possible neuroelectrophysiological mechanisms underlying the previously reported treatment effects of DMBI in comparison with those of cognitive behavioral therapy (CBT). Seventy-five age-, gender-, and education-matched participants with depression were randomly assigned to receive either CBT or DMBI or placed on a waitlist. Eyes-closed resting EEG data were obtained individually before and after 10 weeks. After intervention, the DMBI group demonstrated significantly enhanced frontal alpha asymmetry (an index of positive mood) and intra- and interhemispheric theta coherence in frontoposterior and posterior brain regions (an index of attention). In contrast, neither the CBT nor the waitlist group showed significant changes in EEG activity patterns. Furthermore, the asymmetry and coherence indices of the DMBI group were correlated with self-reported depression severity levels and performance on an attention test, respectively. The present findings provide support for the effects of a Chinese Chan-based mind-body intervention in fostering human brain states that can facilitate positive mood and an attentive mind.
Evidence-based Complementary and Alternative Medicine | 2012
Agnes S. Chan; Sophia L. Sze; Yvonne M.Y. Han; Mei-chun Cheung
Executive dysfunctions have been found to be related to repetitive/disinhibited behaviors and social deficits in autism spectrum disorders (ASDs). This study aims to investigate the potential effect of a Shaolin-medicine-based dietary modification on improving executive functions and behavioral symptoms of ASD and exploring the possible underlying neurophysiological mechanisms. Twenty-four children with ASD were randomly assigned into the experimental (receiving dietary modification for one month) and the control (no modification) groups. Each child was assessed on his/her executive functions, behavioral problems based on parental ratings, and event-related electroencephalography (EEG) activity during a response-monitoring task before and after the one month. The experimental group demonstrated significantly improved mental flexibility and inhibitory control after the diet modification, which continued to have a large effect size within the low-functioning subgroup. Such improvements coincided with positive evaluations by their parents on social communication abilities and flexible inhibitory control of daily behaviors and significantly enhanced event-related EEG activity at the rostral and subgenual anterior cingulate cortex. In contrast, the control group did not show any significant improvements. These positive outcomes of a one-month dietary modification on children with ASD have implicated its potential clinical applicability for patients with executive function deficits.
Neuropsychology (journal) | 2016
Michael K. Yeung; Yvonne M.Y. Han; Sophia L. Sze; Agnes S. Chan
OBJECTIVE Deficits in cognitive flexibility have been suggested to underlie the repetitive and stereotyped behavior in individuals with autism spectrum disorders (ASD). Because cognitive flexibility is primarily mediated by the frontal lobe, where structural and functional abnormalities have been extensively found in these individuals, it is conceivable that their deficits in cognitive flexibility are related to abnormal activations of the frontal lobe. The present study investigates cognitive flexibility and its underlying neurophysiological activities as indicated by theta oscillations in children with ASD. METHOD Twenty-five children with high-functioning ASD and 25 IQ- and age-matched typically developing (TD) children were subjected to neuropsychological assessments on cognitive flexibility and electroencephalography recordings. RESULTS The children with ASD performed significantly worse than the TD children across the tasks of cognitive flexibility, including the modified Wisconsin Card Sorting Test (WCST). These children also demonstrated a reduced increase of the theta power localized in multiple brain regions, including various sectors of the frontal lobe at the late stage (i.e., 600 ms-900 ms poststimulus interval) but not the early stage (i.e., 250 ms-550 ms poststimulus interval) of the performance of the modified WCST. The suppressed late frontal theta activities were further shown to be significantly correlated with a poorer performance on the cognitive flexibility measures. CONCLUSION Our findings suggest that abnormal activations of multiple cortical regions, especially the frontal lobe, form the neural basis of the cognitive flexibility deficits in children with ASD. In addition, we found an EEG marker of cognitive flexibility which could be used to monitor treatment outcomes objectively.
Frontiers in Immunology | 2017
Yvonne M.Y. Han; Winnie K. Cheung; Chun Kwok Wong; Sophia L. Sze; Timmy W. S. Cheng; Michael K. Yeung; Agnes S. Chan
Previous studies have shown that immunological factors are involved in the pathogenesis of autism spectrum disorders (ASDs). However, this research has been conducted almost exclusively in Western contexts, and only a handful of studies on immune measures have been conducted in Asian populations, such as Chinese populations. The present study examined whether immunological abnormalities are associated with cognitive deficits and problem behaviors in Chinese children with ASD and whether these children show different immunological profiles. Thirteen typically developing (TD) children and 22 children with ASD, aged 6–17 years, participated voluntarily in the study. Executive functions and short-term memory were measured using neuropsychological tests, and behavioral measures were assessed using parent ratings. The children were also assessed on immunological measures, specifically, the levels of cytokines and chemokines in the blood serum. Children with ASD showed greater deficits in cognitive functions, as well as altered levels of immunological measures, including CCL2, CCL5, and CXCL9 levels, compared to TD children, and the cognitive functions and associated behavioral deficits of children with ASD were significantly associated with different immunological measures. The children were further sub-classified into ASD with only autistic features (ASD-only) or ASD comorbid with attention deficit hyperactivity disorder (ASD + ADHD). The comorbidity results showed that there were no differences between the two groups of ASD children in any of the cognitive or behavioral measures. However, the results pertaining to immunological measures showed that the children with ASD-only and ASD + ADHD exhibited distinct cytokine and chemokine profiles and that abnormal immunologic function was associated with cognitive functions and inattention/hyperactivity symptoms. These results support the notion that altered immune functions may play a role in the selective cognitive and behavioral symptoms of ASD.
Mental Health, Religion & Culture | 2011
Miranda Chi Kuan Mak; Yvonne M.Y. Han; Jianing You; Mingxuan Jin; Michael Harris Bond
This study examines the role of three dimensions of social axioms (religiosity, social cynicism, and reward for application) as mediators of the relationship between insecure attachment styles to mother and the life satisfaction of Hong Kong Chinese and Americans. Participants were 143 university students from Hong Kong and 187 from the United States. As predicted, attachment-avoidant individuals had higher levels of social cynicism and lower levels of reward for application, while attachment-anxious individuals showed higher levels of social cynicism. Both social cynicism and reward for application mediated the link between insecure maternal attachment styles and life satisfaction, confirming the position that experiences with mothering shape beliefs about the world that in turn shape life outcomes. Anxious and avoidant maternal attachment styles correlated differently with religiosity, social cynicism, and reward for application in the two cultures, suggesting a distinctive role for beliefs about religious institutions and a Supreme Being for Americans.
Frontiers in Psychology | 2015
Agnes S. Chan; Yvonne M.Y. Han; Sophia L. Sze; Eliza M. Lau
The memory deficits found in individuals with autism spectrum disorder (ASD) may be caused by the lack of an effective strategy to aid memory. The executive control of memory processing is mediated largely by the timely coupling between frontal and posterior brain regions. The present study aimed to explore the potential effect of a Chinese mind–body exercise, namely Nei Gong, for enhancing learning and memory in children with ASD, and the possible neural basis of the improvement. Sixty-six children with ASD were randomly assigned to groups receiving Nei Gong training (NGT), progressive muscle relaxation (PMR) training, or no training for 1 month. Before and after training, the participants were tested individually on a computerized visual memory task while EEG signals were acquired during the memory encoding phase. Children in the NGT group demonstrated significantly enhanced memory performance and more effective use of a memory strategy, which was not observed in the other two groups. Furthermore, the improved memory after NGT was consistent with findings of elevated EEG theta coherence between frontal and posterior brain regions, a measure of functional coupling. The scalp EEG signals were localized by the standardized low resolution brain electromagnetic tomography method and found to originate from a neural network that promotes effective memory processing, including the prefrontal cortex, the parietal cortex, and the medial and inferior temporal cortex. This alteration in neural processing was not found in children receiving PMR or in those who received no training. The present findings suggest that the mind–body exercise program may have the potential effect on modulating neural functional connectivity underlying memory processing and hence enhance memory functions in individuals with autism.