chrysi stefanidou | Queen Mary, University of London (original) (raw)
Papers by chrysi stefanidou
PLOS ONE, Jul 24, 2017
Previous event-related potential (ERP) research utilizing oddball stimulus paradigms suggests dim... more Previous event-related potential (ERP) research utilizing oddball stimulus paradigms suggests diminished processing of speech versus non-speech sounds in children with an Autism Spectrum Disorder (ASD). However, brain mechanisms underlying these speech processing abnormalities, and to what extent they are related to poor language abilities in this population remain unknown. In the current study, we utilized a novel paired repetition paradigm in order to investigate ERP responses associated with the detection and discrimination of speech and non-speech sounds in 4-to 6-year old children with ASD, compared with gender and verbal age matched controls. ERPs were recorded while children passively listened to pairs of stimuli that were either both speech sounds, both non-speech sounds, speech followed by non-speech, or non-speech followed by speech. Control participants exhibited N330 match/mismatch responses measured from temporal electrodes, reflecting speech versus non-speech detection, bilaterally, whereas children with ASD exhibited this effect only over temporal electrodes in the left hemisphere. Furthermore, while the control groups exhibited match/mismatch effects at approximately 600 ms (central N600, temporal P600) when a non-speech sound was followed by a speech sound, these effects were absent in the ASD group. These findings suggest that children with ASD fail to activate right hemisphere mechanisms, likely associated with social or emotional aspects of speech detection, when distinguishing non-speech from speech stimuli. Together, these results demonstrate the presence of atypical speech versus non-speech processing in children with ASD when compared with typically developing children matched on verbal age.
Acta Psychiatrica Scandinavica, Nov 21, 2015
Objective: This proof of principle study evaluated the effectiveness and feasibility of a brief m... more Objective: This proof of principle study evaluated the effectiveness and feasibility of a brief motivational intervention, delivered in mental health inpatient settings, to improve engagement in treatment for drug and alcohol misuse. Method: A randomized controlled trial using concealed randomization, blind, independent assessment of outcome at 3 months. Participants were 59 new adult admissions, to 6 acute mental health hospital units in one UK mental health service, with schizophrenia related or bipolar disorder diagnoses, users of community mental health services and also misusing alcohol and/or drugs. Participants were randomised to Brief Integrated Motivational Intervention (BMI) with Treatment As Usual (TAU), or TAU alone. The BMI took place over a 2-week period and encouraged participants to explore substance use and its impact on mental health. Results: 59 inpatients (BMI n=30; TAU n=29) were randomised, the BMI was associated with a 63% relative odds increase in the primary outcome engagement in treatment (OR 1.63 (95% CI 1.01 to 2.65; p=0.047)), at 3 months. Qualitative interviews with staff and participants indicated that the BMI was both feasible and acceptable. Conclusion Mental health hospital admissions present an opportunity for brief motivational interventions focussed on substance misuse, and can lead to improvements in engagement.
The work presented in the current thesis explored the nature, time-course, and neurodevelopmental... more The work presented in the current thesis explored the nature, time-course, and neurodevelopmental trajectory of the brain mechanisms underlying the perceptual processing of auditory social versus non-social stimuli in typically developing young children, toddlers and young children with autism spectrum disorders, and toddlers who are at risk of developing autism. This was completed through the use of a novel auditory-auditory repetition suppression event-related potentials (ERP) paradigm, which included sounds produced by human actions and non-human/environmental sounds. Standardised behavioural measures were also used for the matching of the groups on language ability, the behavioural characterisation of children on the autism spectrum, and the investigation of the relationship between brain activity and cognitive and social communication skills. The results revealed developmental changes in auditory social processing across two typically developing age groups, as well as atypicalities in both social and non-social processing mechanisms in children with autism spectrum disorders and toddlers at high-risk of developing autism. Together, these findings make a notable contribution to our understanding of the mechanisms underlying typical and atypical development of auditory social information processing.
Frontiers in Integrative Neuroscience, 2013
Research suggests that a subset of children with autism experience notable difficulties and delay... more Research suggests that a subset of children with autism experience notable difficulties and delays in motor skills development, and that a large percentage of children with autism experience deficits in motor resonance. These motor-related deficiencies, which evidence suggests are present from a very early age, are likely to negatively affect social-communicative and language development in this population. Here, we review evidence for delayed, impaired, and atypical motor development in infants and children with autism. We then carefully review and examine the current language and communication-based intervention research that is relevant to motor and motor resonance (i.e., neural "mirroring" mechanisms activated when we observe the actions of others) deficits in children with autism. Finally, we describe research needs and future directions and developments for early interventions aimed at addressing the speech/language and social-communication development difficulties in autism from a motor-related perspective.
doi: 10.3389/fnint.2013.00030 Motor development and motor resonance difficulties in autism: relev... more doi: 10.3389/fnint.2013.00030 Motor development and motor resonance difficulties in autism: relevance to early intervention for language and communication skills
<p>The figure represents the ERP waveforms recorded from the frontal-central electrodes in ... more <p>The figure represents the ERP waveforms recorded from the frontal-central electrodes in the left hemisphere (left side), and frontal-central electrodes in the right hemisphere (right side) in the ASD and the TD control groups.</p
<p>The bar graph shows the mean ERP amplitudes for the P350 component in the fronto-central... more <p>The bar graph shows the mean ERP amplitudes for the P350 component in the fronto-central area in the four conditions the ASD and the TD groups. Asterisks indicate the results of post-hoc paired-sample t-tests: ***-p<0.001, **-p<0.01.</p
<p>The bar graph shows the mean ERP amplitudes for the P600 Late Slow Wave component in the... more <p>The bar graph shows the mean ERP amplitudes for the P600 Late Slow Wave component in the temporal area in the four experimental conditions in the ASD and TD groups. The asterisks indicate the results of the post-hoc paired-sample t-tests:*—p<0.05.</p
ABSTRACT Background: Recent research suggests a possible specific receptive language deficiency i... more ABSTRACT Background: Recent research suggests a possible specific receptive language deficiency in children with autism, such that these children may have lower receptive relative to expressive language skills. However, some limitations of existing studies include the absence of a typically developing comparison control group, as well as use of parent-report measures. Objectives: The present study aimed to explore differences in relative receptive versus expressive language skills in children with autism, compared with a typical child sample. We also explored potential associations between language abilities and autism symptom severity in the children with autism. Methods: Participants were 44 children with ASD and 54 typically developing children, aged 2 to 6 years. Both groups underwent verbal and nonverbal cognitive assessment using the Mullen Scales of Early Learning. The Autism Diagnostic Observation Schedule (ADOS) was also administered to the autism participant group. The two groups were compared on verbal abilities, including receptive and expressive language age-equivalents, and within-subject difference scores for receptive versus expressive language (RL-EL) whereby a positive value was indicative of higher receptive language than expressive and a negative value was indicative of lower receptive than expressive language. The ASD group data were also examined for correlations between language abilities and autism symptom severity indexed by ADOS Total scores. Results: Both receptive and expressive language skills were found to be significantly lower in the autism group compared with the typical group (p<0.01). However, there was no evidence for differences in the relative receptive versus expressive language development trends or trajectories of the autism group compared with the typical group (p=0.23; TD mean RL-EL = 0.5, SE = 0.99; ASD mean RL-EL = -0.6, SE = 1.1). Furthermore, in the autism group, language scores (receptive and expressive average) were moderately negatively correlated with ADOS Total scores (r=-.48, p<0.01). Conclusions: These results indicate that the children with autism had clear deficits in both receptive and expressive language when compared with typically developing children. However, although the mean difference between receptive and expressive language (RL-EL) abilities was found to be numerically negative for children with autism and positive for typical controls, this difference did not nearly approach statistical significance. Thus, the current results do not support the hypothesis of a specific receptive language deficiency in young children with autism. Although some previous studies have uncovered evidence for a specific receptive language deficit in children with autism, some of these studies used developmentally delayed control children who exhibited a tendency for impaired expressive relative to receptive language abilities. Furthermore, the current findings are consistent with recent findings of Kover et al (2013), who also found no evidence for a relative receptive versus expressive language deficiency in autism compared with typical controls; but did find an impoverished rate of receptive versus expressive language development with age in this population. Therefore, specific receptive language differences in childhood autism may be a result of early learning differences such that RL-EL performance differences do not become apparent until the children are somewhat older.
<p>The bar graph shows the mean ERP amplitudes for the N600 Late Slow Wave component in the... more <p>The bar graph shows the mean ERP amplitudes for the N600 Late Slow Wave component in the central area in the four experimental conditions in the ASD and TD groups. The asterisks indicate the results of the post-hoc paired-sample t-tests: *—p<0.05.</p
<p>Characteristics of children with ASD and typically developing (TD) participants individu... more <p>Characteristics of children with ASD and typically developing (TD) participants individually matched on verbal mental age and the results of the group comparisons based on independent sample t-tests.</p
<p>The figure represents the ERP waveforms recorded from the temporal left (left side) and ... more <p>The figure represents the ERP waveforms recorded from the temporal left (left side) and temporal right (right side) electrodes in the ASD and the TD control groups.</p
<p>Scalp potential distributions in the subtraction of topographical activity in the TD ver... more <p>Scalp potential distributions in the subtraction of topographical activity in the TD versus ASD groups in the selected time interval (300–400 ms) in the four experimental conditions.</p
<p>The electrode locations in the frontal-central and temporal areas.</p
Additional file 2. ESCogS tasks. Description of the ability assessed, passing criteria and contro... more Additional file 2. ESCogS tasks. Description of the ability assessed, passing criteria and control trials for each task in the ESCogS
Additional file 1. Social cognition in neurogenetic syndromes. Description of counterbalanced ord... more Additional file 1. Social cognition in neurogenetic syndromes. Description of counterbalanced orders for Early Social Cognition Scale tasks
e feasibility and impact last 3 months. The primary outcome is engagement in treatment for substa... more e feasibility and impact last 3 months. The primary outcome is engagement in treatment for substance misuse, and secondary outcomes
Journal of Autism and Developmental Disorders, 2020
We directly assessed the broader aspects of sociability (social enjoyment, social motivation, soc... more We directly assessed the broader aspects of sociability (social enjoyment, social motivation, social interaction skills and social discomfort) in individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and their association with autism characteristics and chronological age in these groups. Individuals with FXS (p < 0.01) and RTS (p < 0.01) showed poorer quality of eye contact compared to individuals with CdLS. Individuals with FXS showed less person and more object attention than individuals with CdLS (p < 0.01). Associations between sociability and autism characteristics and chronological age differed between groups, which may indicate divergence in the development and aetiology of different components of sociability across these groups. Findings indicate that individuals with CdLS, FXS and RTS show unique profiles of sociability.
Acta psychiatrica Scandinavica, Jan 21, 2015
This proof of principle study evaluated the effectiveness and feasibility of a brief motivational... more This proof of principle study evaluated the effectiveness and feasibility of a brief motivational intervention, delivered in mental health in-patient settings, to improve engagement in treatment for drug and alcohol misuse. A randomised controlled trial using concealed randomisation, blind, independent assessment of outcome at 3 months. Participants were 59 new adult admissions, to six acute mental health hospital units in one UK mental health service, with schizophrenia related or bipolar disorder diagnoses, users of community mental health services and also misusing alcohol and/or drugs. Participants were randomised to Brief Integrated Motivational Intervention (BIMI) with Treatment As Usual (TAU), or TAU alone. The BIMI took place over a 2-week period and encouraged participants to explore substance use and its impact on mental health. Fifty-nine in-patients (BIMI n = 30; TAU n = 29) were randomised, the BIMI was associated with a 63% relative odds increase in the primary outcome...
PLOS ONE, Jul 24, 2017
Previous event-related potential (ERP) research utilizing oddball stimulus paradigms suggests dim... more Previous event-related potential (ERP) research utilizing oddball stimulus paradigms suggests diminished processing of speech versus non-speech sounds in children with an Autism Spectrum Disorder (ASD). However, brain mechanisms underlying these speech processing abnormalities, and to what extent they are related to poor language abilities in this population remain unknown. In the current study, we utilized a novel paired repetition paradigm in order to investigate ERP responses associated with the detection and discrimination of speech and non-speech sounds in 4-to 6-year old children with ASD, compared with gender and verbal age matched controls. ERPs were recorded while children passively listened to pairs of stimuli that were either both speech sounds, both non-speech sounds, speech followed by non-speech, or non-speech followed by speech. Control participants exhibited N330 match/mismatch responses measured from temporal electrodes, reflecting speech versus non-speech detection, bilaterally, whereas children with ASD exhibited this effect only over temporal electrodes in the left hemisphere. Furthermore, while the control groups exhibited match/mismatch effects at approximately 600 ms (central N600, temporal P600) when a non-speech sound was followed by a speech sound, these effects were absent in the ASD group. These findings suggest that children with ASD fail to activate right hemisphere mechanisms, likely associated with social or emotional aspects of speech detection, when distinguishing non-speech from speech stimuli. Together, these results demonstrate the presence of atypical speech versus non-speech processing in children with ASD when compared with typically developing children matched on verbal age.
Acta Psychiatrica Scandinavica, Nov 21, 2015
Objective: This proof of principle study evaluated the effectiveness and feasibility of a brief m... more Objective: This proof of principle study evaluated the effectiveness and feasibility of a brief motivational intervention, delivered in mental health inpatient settings, to improve engagement in treatment for drug and alcohol misuse. Method: A randomized controlled trial using concealed randomization, blind, independent assessment of outcome at 3 months. Participants were 59 new adult admissions, to 6 acute mental health hospital units in one UK mental health service, with schizophrenia related or bipolar disorder diagnoses, users of community mental health services and also misusing alcohol and/or drugs. Participants were randomised to Brief Integrated Motivational Intervention (BMI) with Treatment As Usual (TAU), or TAU alone. The BMI took place over a 2-week period and encouraged participants to explore substance use and its impact on mental health. Results: 59 inpatients (BMI n=30; TAU n=29) were randomised, the BMI was associated with a 63% relative odds increase in the primary outcome engagement in treatment (OR 1.63 (95% CI 1.01 to 2.65; p=0.047)), at 3 months. Qualitative interviews with staff and participants indicated that the BMI was both feasible and acceptable. Conclusion Mental health hospital admissions present an opportunity for brief motivational interventions focussed on substance misuse, and can lead to improvements in engagement.
The work presented in the current thesis explored the nature, time-course, and neurodevelopmental... more The work presented in the current thesis explored the nature, time-course, and neurodevelopmental trajectory of the brain mechanisms underlying the perceptual processing of auditory social versus non-social stimuli in typically developing young children, toddlers and young children with autism spectrum disorders, and toddlers who are at risk of developing autism. This was completed through the use of a novel auditory-auditory repetition suppression event-related potentials (ERP) paradigm, which included sounds produced by human actions and non-human/environmental sounds. Standardised behavioural measures were also used for the matching of the groups on language ability, the behavioural characterisation of children on the autism spectrum, and the investigation of the relationship between brain activity and cognitive and social communication skills. The results revealed developmental changes in auditory social processing across two typically developing age groups, as well as atypicalities in both social and non-social processing mechanisms in children with autism spectrum disorders and toddlers at high-risk of developing autism. Together, these findings make a notable contribution to our understanding of the mechanisms underlying typical and atypical development of auditory social information processing.
Frontiers in Integrative Neuroscience, 2013
Research suggests that a subset of children with autism experience notable difficulties and delay... more Research suggests that a subset of children with autism experience notable difficulties and delays in motor skills development, and that a large percentage of children with autism experience deficits in motor resonance. These motor-related deficiencies, which evidence suggests are present from a very early age, are likely to negatively affect social-communicative and language development in this population. Here, we review evidence for delayed, impaired, and atypical motor development in infants and children with autism. We then carefully review and examine the current language and communication-based intervention research that is relevant to motor and motor resonance (i.e., neural "mirroring" mechanisms activated when we observe the actions of others) deficits in children with autism. Finally, we describe research needs and future directions and developments for early interventions aimed at addressing the speech/language and social-communication development difficulties in autism from a motor-related perspective.
doi: 10.3389/fnint.2013.00030 Motor development and motor resonance difficulties in autism: relev... more doi: 10.3389/fnint.2013.00030 Motor development and motor resonance difficulties in autism: relevance to early intervention for language and communication skills
<p>The figure represents the ERP waveforms recorded from the frontal-central electrodes in ... more <p>The figure represents the ERP waveforms recorded from the frontal-central electrodes in the left hemisphere (left side), and frontal-central electrodes in the right hemisphere (right side) in the ASD and the TD control groups.</p
<p>The bar graph shows the mean ERP amplitudes for the P350 component in the fronto-central... more <p>The bar graph shows the mean ERP amplitudes for the P350 component in the fronto-central area in the four conditions the ASD and the TD groups. Asterisks indicate the results of post-hoc paired-sample t-tests: ***-p<0.001, **-p<0.01.</p
<p>The bar graph shows the mean ERP amplitudes for the P600 Late Slow Wave component in the... more <p>The bar graph shows the mean ERP amplitudes for the P600 Late Slow Wave component in the temporal area in the four experimental conditions in the ASD and TD groups. The asterisks indicate the results of the post-hoc paired-sample t-tests:*—p<0.05.</p
ABSTRACT Background: Recent research suggests a possible specific receptive language deficiency i... more ABSTRACT Background: Recent research suggests a possible specific receptive language deficiency in children with autism, such that these children may have lower receptive relative to expressive language skills. However, some limitations of existing studies include the absence of a typically developing comparison control group, as well as use of parent-report measures. Objectives: The present study aimed to explore differences in relative receptive versus expressive language skills in children with autism, compared with a typical child sample. We also explored potential associations between language abilities and autism symptom severity in the children with autism. Methods: Participants were 44 children with ASD and 54 typically developing children, aged 2 to 6 years. Both groups underwent verbal and nonverbal cognitive assessment using the Mullen Scales of Early Learning. The Autism Diagnostic Observation Schedule (ADOS) was also administered to the autism participant group. The two groups were compared on verbal abilities, including receptive and expressive language age-equivalents, and within-subject difference scores for receptive versus expressive language (RL-EL) whereby a positive value was indicative of higher receptive language than expressive and a negative value was indicative of lower receptive than expressive language. The ASD group data were also examined for correlations between language abilities and autism symptom severity indexed by ADOS Total scores. Results: Both receptive and expressive language skills were found to be significantly lower in the autism group compared with the typical group (p<0.01). However, there was no evidence for differences in the relative receptive versus expressive language development trends or trajectories of the autism group compared with the typical group (p=0.23; TD mean RL-EL = 0.5, SE = 0.99; ASD mean RL-EL = -0.6, SE = 1.1). Furthermore, in the autism group, language scores (receptive and expressive average) were moderately negatively correlated with ADOS Total scores (r=-.48, p<0.01). Conclusions: These results indicate that the children with autism had clear deficits in both receptive and expressive language when compared with typically developing children. However, although the mean difference between receptive and expressive language (RL-EL) abilities was found to be numerically negative for children with autism and positive for typical controls, this difference did not nearly approach statistical significance. Thus, the current results do not support the hypothesis of a specific receptive language deficiency in young children with autism. Although some previous studies have uncovered evidence for a specific receptive language deficit in children with autism, some of these studies used developmentally delayed control children who exhibited a tendency for impaired expressive relative to receptive language abilities. Furthermore, the current findings are consistent with recent findings of Kover et al (2013), who also found no evidence for a relative receptive versus expressive language deficiency in autism compared with typical controls; but did find an impoverished rate of receptive versus expressive language development with age in this population. Therefore, specific receptive language differences in childhood autism may be a result of early learning differences such that RL-EL performance differences do not become apparent until the children are somewhat older.
<p>The bar graph shows the mean ERP amplitudes for the N600 Late Slow Wave component in the... more <p>The bar graph shows the mean ERP amplitudes for the N600 Late Slow Wave component in the central area in the four experimental conditions in the ASD and TD groups. The asterisks indicate the results of the post-hoc paired-sample t-tests: *—p<0.05.</p
<p>Characteristics of children with ASD and typically developing (TD) participants individu... more <p>Characteristics of children with ASD and typically developing (TD) participants individually matched on verbal mental age and the results of the group comparisons based on independent sample t-tests.</p
<p>The figure represents the ERP waveforms recorded from the temporal left (left side) and ... more <p>The figure represents the ERP waveforms recorded from the temporal left (left side) and temporal right (right side) electrodes in the ASD and the TD control groups.</p
<p>Scalp potential distributions in the subtraction of topographical activity in the TD ver... more <p>Scalp potential distributions in the subtraction of topographical activity in the TD versus ASD groups in the selected time interval (300–400 ms) in the four experimental conditions.</p
<p>The electrode locations in the frontal-central and temporal areas.</p
Additional file 2. ESCogS tasks. Description of the ability assessed, passing criteria and contro... more Additional file 2. ESCogS tasks. Description of the ability assessed, passing criteria and control trials for each task in the ESCogS
Additional file 1. Social cognition in neurogenetic syndromes. Description of counterbalanced ord... more Additional file 1. Social cognition in neurogenetic syndromes. Description of counterbalanced orders for Early Social Cognition Scale tasks
e feasibility and impact last 3 months. The primary outcome is engagement in treatment for substa... more e feasibility and impact last 3 months. The primary outcome is engagement in treatment for substance misuse, and secondary outcomes
Journal of Autism and Developmental Disorders, 2020
We directly assessed the broader aspects of sociability (social enjoyment, social motivation, soc... more We directly assessed the broader aspects of sociability (social enjoyment, social motivation, social interaction skills and social discomfort) in individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and their association with autism characteristics and chronological age in these groups. Individuals with FXS (p < 0.01) and RTS (p < 0.01) showed poorer quality of eye contact compared to individuals with CdLS. Individuals with FXS showed less person and more object attention than individuals with CdLS (p < 0.01). Associations between sociability and autism characteristics and chronological age differed between groups, which may indicate divergence in the development and aetiology of different components of sociability across these groups. Findings indicate that individuals with CdLS, FXS and RTS show unique profiles of sociability.
Acta psychiatrica Scandinavica, Jan 21, 2015
This proof of principle study evaluated the effectiveness and feasibility of a brief motivational... more This proof of principle study evaluated the effectiveness and feasibility of a brief motivational intervention, delivered in mental health in-patient settings, to improve engagement in treatment for drug and alcohol misuse. A randomised controlled trial using concealed randomisation, blind, independent assessment of outcome at 3 months. Participants were 59 new adult admissions, to six acute mental health hospital units in one UK mental health service, with schizophrenia related or bipolar disorder diagnoses, users of community mental health services and also misusing alcohol and/or drugs. Participants were randomised to Brief Integrated Motivational Intervention (BIMI) with Treatment As Usual (TAU), or TAU alone. The BIMI took place over a 2-week period and encouraged participants to explore substance use and its impact on mental health. Fifty-nine in-patients (BIMI n = 30; TAU n = 29) were randomised, the BIMI was associated with a 63% relative odds increase in the primary outcome...