The Experts below are selected from a list of 24474 Experts worldwide ranked by ideXlab platform
Chantal Kemner - One of the best experts on this subject based on the ideXlab platform.
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atypical processing of fearful face voice pairs in Pervasive Developmental Disorder an erp study
Clinical Neurophysiology, 2008Co-Authors: Maurice J C M Magnee, Beatrice De Gelder, Herman Van Engeland, Chantal KemnerAbstract:Abstract Objective An important premise for successful social-affective communication is rapid perception of visual and auditory emotional cues, as well as their multisensory integration (MSI). We investigated to what extent a deficit in recognition of emotions in individuals with Pervasive Developmental Disorder (PDD) may have its roots in abnormal MSI of emotional cues provided by the sight of a facial expression and an emotional tone of voice. Methods In twelve high-functioning, adult PDD individuals and thirteen age- and IQ-matched controls, (1) the processing of fearful faces was compared with that of happy faces; (2) MSI was assessed by characterizing the interaction effects of crossmodal presentation, using EEG. Results Increased P1 and N170 amplitudes were seen in response to fearful faces compared with happy faces in both groups. However, PDD individuals differed from healthy controls in MSI of fearful information from visual and auditory cues. Conclusions Both groups show a similar pattern as concerns the early components of visual emotion processing, but there are anomalies in processing of fearful face–voice combinations in the PDD group. Significance Because of the importance of rapid MSI for social competence, MSI anomalies in PDD may be linked to the observed deficits in their emotional behavior.
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facial electromyographic responses to emotional information from faces and voices in individuals with Pervasive Developmental Disorder
Journal of Child Psychology and Psychiatry, 2007Co-Authors: Maurice J C M Magnee, Beatrice De Gelder, Chantal Kemner, Herman Van EngelandAbstract:Background: Despite extensive research, it is still debated whether impairments in social skills of individuals with Pervasive Developmental Disorder (PDD) are related to specific deficits in the early processing of emotional information. We aimed to test both automatic processing of facial affect as well as the integration of auditory and visual emotion cues in individuals with PDD. Methods: In a group of high-functioning adult individuals with PDD and an age- and IQ-matched control group, we measured facial electromyography (EMG) following presentation of visual emotion stimuli (facial expressions) as well as the presentation of audiovisual emotion pairs (faces plus voices). This emotionally driven EMG activity is considered to be a direct correlate of automatic affect processing that is not under intentional control. Results: Our data clearly indicate that among individuals with PDD facial EMG activity is heightened in response to happy and fearful faces, and intact in response to audiovisual affective information. Conclusions: This study provides evidence for enhanced sensitivity to facial cues at the level of reflex-like emotional responses in individuals with PDD. Furthermore, the findings argue against impairments in crossmodal affect processing at this level of perception. However, given how little comparative work has been done in the area of multisensory perception, there is certainly need for further exploration.
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face processing in Pervasive Developmental Disorder pdd the roles of expertise and spatial frequency
Journal of Neural Transmission, 2007Co-Authors: M A Boeschoten, Chantal Kemner, Herman Van Engeland, J L KenemansAbstract:Both a reduced face expertise and a basic abnormality in visual information, e.g. spatial frequency, processing have been proposed as possible causes of the abnormal face processing in Pervasive Developmental Disorder (PDD). This study investigated both the roles of expertise and spatial frequency for face processing in PDD. Event-related potentials (ERPs) and dipole sources were measured in response to (upright/inverted) high- and low-pass filtered faces, houses, and stimuli for which children with PDD were experts. ERP analyses for specific posterior electrodes showed no differences between children with PDD and matched controls, but source analyses did. These showed that controls activated specialized brain sources for the processing of faces, which was dependent on low spatial frequency content. However, children with PDD did not. Importantly, present results argue against the idea that this is due to a reduced face expertise on the part of the children with PDD, but instead support an abnormality in spatial frequency processing.
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integrity of lateral and feedbackward connections in visual processing in children with Pervasive Developmental Disorder
Neuropsychologia, 2007Co-Authors: Chantal Kemner, Victor A F Lamme, I Kovacs, Herman Van EngelandAbstract:Enhanced visual detail processing in subjects with Pervasive Developmental Disorder (PDD) has been related to impairments in feature integration. The functional integrity of two types of neuronal connections involved in visual feature integration, namely horizontal and feedbackward connections, were tested. Sixteen children with PDD and 17 age- and IQ-matched control children (mean age 13.3 years) were included. In a texture segregation task the difference in ERP response to homogeneous and checkered visual stimuli was determined. Additionally, in a contour integration task subjects had to point out a contour consisting of colinearly aligned Gabor signals in backgrounds increasing in noise. Children with PDD showed a normal performance on the contour integration task, suggesting that neurons in the primary visual cortex of children with PDD can effectively integrate the activity of local detectors that process different aspects of the same object information by making use of long-range lateral connections. The amplitude of ERP activity related to texture segregation was also not different between the PDD and control groups, indicating functional visual feedback mechanisms between V1 and higher order areas in subjects with PDD. However, a difference in latency of texture-segmentation related activity between the groups was noted. This effect did not reach significance, which could be due to the small N of the study. Therefore, the data need replication in a study with larger samples before more definitive conclusions can be drawn.
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erps and eye movements reflect atypical visual perception in Pervasive Developmental Disorder
Journal of Autism and Developmental Disorders, 2006Co-Authors: Chantal Kemner, Herman Van EngelandAbstract:Many studies of eye tracking or event-related brain potentials (ERPs) in subjects with Pervasive Developmental Disorder (PDD) have yielded inconsistent results on attentional processing. However, recent studies have indicated that there are specific abnormalities in early processing that are probably related to perception. ERP amplitudes in response to visual stimuli, measured above the occipital (modality-specific) cortex, are reported to be abnormally small in patients with PDD, and the abnormal visual processing is possibly associated with the spatial visual frequency content of stimuli. It is suggested that subjects with PDD show abnormal activation of visual pathways dedicated to the processing of high and low spatial frequencies.
Herman Van Engeland - One of the best experts on this subject based on the ideXlab platform.
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facial electromyographic responses to emotional information from faces and voices in individuals with Pervasive Developmental Disorder
Journal of Child Psychology and Psychiatry, 2007Co-Authors: Maurice J C M Magnee, Beatrice De Gelder, Chantal Kemner, Herman Van EngelandAbstract:Background: Despite extensive research, it is still debated whether impairments in social skills of individuals with Pervasive Developmental Disorder (PDD) are related to specific deficits in the early processing of emotional information. We aimed to test both automatic processing of facial affect as well as the integration of auditory and visual emotion cues in individuals with PDD. Methods: In a group of high-functioning adult individuals with PDD and an age- and IQ-matched control group, we measured facial electromyography (EMG) following presentation of visual emotion stimuli (facial expressions) as well as the presentation of audiovisual emotion pairs (faces plus voices). This emotionally driven EMG activity is considered to be a direct correlate of automatic affect processing that is not under intentional control. Results: Our data clearly indicate that among individuals with PDD facial EMG activity is heightened in response to happy and fearful faces, and intact in response to audiovisual affective information. Conclusions: This study provides evidence for enhanced sensitivity to facial cues at the level of reflex-like emotional responses in individuals with PDD. Furthermore, the findings argue against impairments in crossmodal affect processing at this level of perception. However, given how little comparative work has been done in the area of multisensory perception, there is certainly need for further exploration.
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face processing in Pervasive Developmental Disorder pdd the roles of expertise and spatial frequency
Journal of Neural Transmission, 2007Co-Authors: M A Boeschoten, Chantal Kemner, Herman Van Engeland, J L KenemansAbstract:Both a reduced face expertise and a basic abnormality in visual information, e.g. spatial frequency, processing have been proposed as possible causes of the abnormal face processing in Pervasive Developmental Disorder (PDD). This study investigated both the roles of expertise and spatial frequency for face processing in PDD. Event-related potentials (ERPs) and dipole sources were measured in response to (upright/inverted) high- and low-pass filtered faces, houses, and stimuli for which children with PDD were experts. ERP analyses for specific posterior electrodes showed no differences between children with PDD and matched controls, but source analyses did. These showed that controls activated specialized brain sources for the processing of faces, which was dependent on low spatial frequency content. However, children with PDD did not. Importantly, present results argue against the idea that this is due to a reduced face expertise on the part of the children with PDD, but instead support an abnormality in spatial frequency processing.
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integrity of lateral and feedbackward connections in visual processing in children with Pervasive Developmental Disorder
Neuropsychologia, 2007Co-Authors: Chantal Kemner, Victor A F Lamme, I Kovacs, Herman Van EngelandAbstract:Enhanced visual detail processing in subjects with Pervasive Developmental Disorder (PDD) has been related to impairments in feature integration. The functional integrity of two types of neuronal connections involved in visual feature integration, namely horizontal and feedbackward connections, were tested. Sixteen children with PDD and 17 age- and IQ-matched control children (mean age 13.3 years) were included. In a texture segregation task the difference in ERP response to homogeneous and checkered visual stimuli was determined. Additionally, in a contour integration task subjects had to point out a contour consisting of colinearly aligned Gabor signals in backgrounds increasing in noise. Children with PDD showed a normal performance on the contour integration task, suggesting that neurons in the primary visual cortex of children with PDD can effectively integrate the activity of local detectors that process different aspects of the same object information by making use of long-range lateral connections. The amplitude of ERP activity related to texture segregation was also not different between the PDD and control groups, indicating functional visual feedback mechanisms between V1 and higher order areas in subjects with PDD. However, a difference in latency of texture-segmentation related activity between the groups was noted. This effect did not reach significance, which could be due to the small N of the study. Therefore, the data need replication in a study with larger samples before more definitive conclusions can be drawn.
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erps and eye movements reflect atypical visual perception in Pervasive Developmental Disorder
Journal of Autism and Developmental Disorders, 2006Co-Authors: Chantal Kemner, Herman Van EngelandAbstract:Many studies of eye tracking or event-related brain potentials (ERPs) in subjects with Pervasive Developmental Disorder (PDD) have yielded inconsistent results on attentional processing. However, recent studies have indicated that there are specific abnormalities in early processing that are probably related to perception. ERP amplitudes in response to visual stimuli, measured above the occipital (modality-specific) cortex, are reported to be abnormally small in patients with PDD, and the abnormal visual processing is possibly associated with the spatial visual frequency content of stimuli. It is suggested that subjects with PDD show abnormal activation of visual pathways dedicated to the processing of high and low spatial frequencies.
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larger brains in medication naive high functioning subjects with Pervasive Developmental Disorder
Journal of Autism and Developmental Disorders, 2004Co-Authors: Saskia J M C Palmen, Chantal Kemner, Hilleke Hulshoff E Pol, Hugo G Schnack, Joost Janssen, Rene S Kahn, Herman Van EngelandAbstract:Background: Are brain volumes of individuals with Pervasive Developmental Disorder (PDD) still enlarged in adolescence and adulthood, and if so, is this enlargement confined to the gray and/or the white matter and is it global or more prominent in specific brain regions. Methods: Brain MRI scans were made of 21 adolescents with PDD and 21 closely matched controls. Results: All brain volumes, except the white matter, were significantly larger in patients. After correction for brain volume, ventricular volumes remained significantly larger in patients. Conclusions: Patients showed a proportional, global increase in gray matter and cerebellum volume, and a disproportional increase in ventricular volumes. Thus, at least in high-functioning patients with PDD, brain enlargement may still be present in adult life.
Marcos T Mercadante - One of the best experts on this subject based on the ideXlab platform.
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brief report prevalence of Pervasive Developmental Disorder in brazil a pilot study
Journal of Autism and Developmental Disorders, 2011Co-Authors: Sabrina Helena Bandini Ribeiro, Cristiane Silvestre De Paula, Eric Fombonne, Marcos T MercadanteAbstract:This pilot study presents preliminary results concerning the prevalence of Pervasive Developmental Disorder (PDD) in South America. It was a three-phase study conducted in a typical town in Southeast Brazil. Case definition was based in a combination of standardized instruments and clinical evaluations by experts. The prevalence of PDD was 27.2/10,000 (95% CI: 17.6–36.8) and some hypotheses were raised to explain this low frequency. Clinical findings of PDD cases were consistent with previous data, such as, male preponderance, more children diagnosed with PDD-NOS than with autistic Disorder, and half of them born from older mothers. Moreover, the study raised concerns about treatment of cases, because identification of PDD had been late and access to services has been very limited.
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Instrument to screen cases of Pervasive Developmental Disorder: a preliminary indication of validity
Revista brasileira de psiquiatria (Sao Paulo Brazil : 1999), 2009Co-Authors: Fábio Pinato Sato, Cristiane Silvestre De Paula, Rosane Lowenthal, Eduardo Yoshio Nakano, Decio Brunoni, José Salomão Schwartzman, Marcos T MercadanteAbstract:OBJECTIVE: To translate into Portuguese, back-translate, culturally adapt and validate a screening instrument for Pervasive Developmental Disorder, the Autism Screening Questionnaire, for use in Brazil. METHOD: A sample of 120 patients was selected based on three groups of 40: patients with a clinical diagnosis of Pervasive Developmental Disorder, Down syndrome, or other psychiatric Disorders. The self-administered questionnaire was applied to the patients' legal guardians. Psychometric measures of the final version of the translated questionnaire were tested. RESULTS: The score of 15 had sensitivity of 92.5% and specificity of 95.5% as a cut-off point for the diagnosis of Pervasive Developmental Disorder. Internal validity for a total of 40 questions was 0.895 for alpha and 0.896 for KR-20, ranging from 0.6 to 0.8 for both coefficients. Test and retest reliability values showed strong agreement for most questions. CONCLUSIONS: The final version of this instrument, translated into Portuguese and adapted to the Brazilian culture, had satisfactory measurement properties, suggesting preliminary validation proprieties. It was an easy-to-apply, useful tool for the diagnostic screening of individuals with Pervasive Developmental Disorder.
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Prevalence of Pervasive Developmental Disorder in Down's syndrome.
Journal of autism and developmental disorders, 2007Co-Authors: Rosane Lowenthal, Cristiane Silvestre De Paula, Decio Brunoni, José Salomão Schwartzman, Marcos T MercadanteAbstract:The frequencies of Pervasive Developmental Disorder (PDD) in Down’s syndrome (DS) have been reported from 1% to 11%. However, it is not clear if the frequency of this co-occurrence is higher or lower than in other mental retardations. We study a large sample of DS population, finding a PDD frequency of 15.6%, with 5.58% of autism (eight males and two females) and 10.05% of PDD non autism (nine males and nine females. The meaning of this frequency is discussed.
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Non-autistic Pervasive Developmental Disorders: Rett syndrome, disintegrative Disorder and Pervasive Developmental Disorder not otherwise specified
Revista brasileira de psiquiatria (Sao Paulo Brazil : 1999), 2006Co-Authors: Marcos T Mercadante, Rutger J Van Der Gaag, Jose S SchwartzmanAbstract:The category "Pervasive Developmental Disorders" includes autistic Disorder, Asperger's syndrome, Rett's syndrome, childhood disintegrative Disorder, and a residual category, named Pervasive Developmental Disorder not otherwise specified. In this review, Rett's syndrome and childhood disintegrative Disorder, which are well-defined categories, will be discussed, as well as the not well defined categories that have been included in the Pervasive Developmental Disorder Not Otherwise Specified group. Different proposals of categorization have been created, some of which based on descriptive phenomenological approach, and others based upon other theoretical perspectives, such as neuropsychology. Current proposals are presented and discussed, followed by critical appraisals on the clinical advantages and disadvantages of these concepts.
Anne Margrethe Myhre - One of the best experts on this subject based on the ideXlab platform.
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Is Long-Term Prognosis for Pervasive Developmental Disorder Not Otherwise Specified Different from Prognosis for Autistic Disorder? Findings from a 30-Year Follow-Up Study
Journal of Autism and Developmental Disorders, 2012Co-Authors: Marianne Mordre, Berit Groholt, Ann Kristin Knudsen, Eili Sponheim, Arnstein Mykletun, Anne Margrethe MyhreAbstract:We followed 74 children with autistic Disorder (AD) and 39 children with Pervasive Developmental Disorder not otherwise specified (PDD NOS) for 17–38 years in a record linkage study. Rates of disability pension award, marital status, criminality and mortality were compared between groups. Disability pension award was the only outcome measure that differed significantly between the AD and PDD NOS groups (89% vs. 72%, p
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is long term prognosis for Pervasive Developmental Disorder not otherwise specified different from prognosis for autistic Disorder findings from a 30 year follow up study
Journal of Autism and Developmental Disorders, 2012Co-Authors: Marianne Mordre, Berit Groholt, Ann Kristin Knudsen, Eili Sponheim, Arnstein Mykletun, Anne Margrethe MyhreAbstract:We followed 74 children with autistic Disorder (AD) and 39 children with Pervasive Developmental Disorder not otherwise specified (PDD NOS) for 17–38 years in a record linkage study. Rates of disability pension award, marital status, criminality and mortality were compared between groups. Disability pension award was the only outcome measure that differed significantly between the AD and PDD NOS groups (89% vs. 72%, p < 0.05). The lower rate of disability pension award in the PDD NOS group was predicted by better psychosocial functioning. The lack of substantial differences in prognosis between the groups supports a dimensional description of autism spectrum Disorder, in line with proposed DSM-V revision.
Herbert Roeyers - One of the best experts on this subject based on the ideXlab platform.
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advancing advanced mind reading tests empathic accuracy in adults with a Pervasive Developmental Disorder
Journal of Child Psychology and Psychiatry, 2001Co-Authors: Herbert Roeyers, Ann Buysse, Koen Ponnet, Bert PichalAbstract:Research using advanced but static mind-reading tests with high-functioning adults with a Pervasive Developmental Disorder (PDD) provided evidence for subtle social cognitive deficits. In the present study, adults with PDD were unimpaired on such tasks, relative to individually matched normal controls. Significant differences between the two groups were, however, found on a more naturalistic empathic accuracy task developed for this study. Participants viewed two videotaped interactions that both depicted a male and female stranger having an initial conversation and were asked to infer the unexpressed thoughts and feelings of the four targets. Subjects with PDD performed significantly worse on the second video. These findings suggest that the mind-reading deficit of a subgroup of able adults with PDD may only be apparent when a sufficiently complex naturalistic assessment method is being used.
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the influence of nonhandicapped peers on the social interactions of children with a Pervasive Developmental Disorder
Journal of Autism and Developmental Disorders, 1996Co-Authors: Herbert RoeyersAbstract:This study investigated whether or not children with autism or a related Pervasive Developmental Disorder (PDD) can benefit from regular opportunities to interact with a normally developing peer, matched as to sex and age. An experimental design with random assignment of subjects to treatment and control groups was used to demonstrate the impact of this peer-mediated intervention. In the treatment group, we found significant improvements in the social behavior of the children with PDD. Several gains were also generalized to interactions with an unfamiliar nonhandicapped peer, to interactions with another child with PDD, and to the large school setting. In the untreated control group, no positive changes were observed. Results suggest that children with PDD can develop peer relations if appropriate social contexts are made available for them.
