Publications by authors named "Alexandra P Key"

Article Synopsis
  • - Over 80% of adults with chronic tic disorder (CTD) show sensory over-responsivity (SOR), which is an increased sensitivity to normal sensory stimuli, potentially linked to sensory gating impairments.
  • - The study compared sensory gating in neurotypical adults and those with CTD using clinical assessments and EEG monitoring, finding that CTD adults had higher levels of SOR but no significant differences in key auditory gating measures.
  • - Results indicated that while there was a relationship between N100 gating and SOR, sensory gating impairments may not be the main cause of SOR in CTD, suggesting the need for more research on this relationship.
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The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. Electroencephalography (EEG) is one of two brain imaging modalities central to the HBCD Study. EEG records electrical signals from the scalp that reflect electrical brain activity.

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Article Synopsis
  • The study aimed to identify specific EEG characteristics in individuals with Rett syndrome (RTT) to determine their potential as objective indicators of brain function.
  • EEG data were collected from 60 females with RTT and 26 neurotypical females, focusing on differences in brain activity and the correlation with clinical severity.
  • Findings showed that RTT participants exhibited greater amplitude variability and low-frequency brain activity, with consistent patterns in EEG power measures that correlated with clinical severity, supporting the use of EEG as an objective assessment tool for RTT.
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Objectives: Children with microcephaly exhibit neurodevelopmental delays and compromised communicative functioning, yielding challenges for clinical assessment and informed intervention. This study characterized auditory neural function and communication abilities in children with microcephaly due to congenital Zika syndrome (CZS).

Design: Click-evoked auditory brainstem responses (ABR) at fast and slow stimulation rates and natural speech-evoked cortical auditory evoked potentials (CAEP) were recorded in 25 Brazilian children with microcephaly related to CZS ( M age: 5.

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Objectives: This study examined the neural mechanisms by which remote microphone (RM) systems might lead to improved behavioral performance on listening-in-noise tasks in autistic and non-autistic youth.

Design: Cortical auditory evoked potentials (CAEPs) were recorded in autistic (n = 25) and non-autistic (n = 22) youth who were matched at the group level on chronological age ( M = 14.21 ± 3.

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Autism spectrum disorder (ASD) is characterized by challenges in social competence that persist in adulthood, yet few treatment options exist. A pilot randomized clinical trial (RCT) of a peer-mediated, theatre-based intervention with established efficacy in youth with ASD was examined in autistic adults. The final sample consisted of forty-seven 18-to-40-year-old participants randomized to the experimental (EXP N = 23) or waitlist control (WLC N = 24) condition.

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Based on the idea that neural entrainment establishes regular attentional fluctuations that facilitate hierarchical processing in both music and language, we hypothesized that individual differences in syntactic (grammatical) skills will be partly explained by patterns of neural responses to musical rhythm. To test this hypothesis, we recorded neural activity using electroencephalography (EEG) while children (N = 25) listened passively to rhythmic patterns that induced different beat percepts. Analysis of evoked beta and gamma activity revealed that individual differences in the magnitude of neural responses to rhythm explained variance in six-year-olds' expressive grammar abilities, beyond and complementarily to their performance in a behavioral rhythm perception task.

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Prader-Willi Syndrome (PWS) is characterized by hyperphagia, an extreme and persistent hunger that emerges in early childhood. We used event-related potentials (ERPs) to objectively investigate brain responses to low- and high-calorie foods, animals, and household objects in 20 satiated adolescents with PWS. Late Positive Potential (LPP) responses to food images did not differ from non-food images.

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Objective: Individuals with autism spectrum disorder (ASD) have significant impairment in social competence and reduced social salience. SENSE Theatre, a peer-mediated, theater-based intervention has demonstrated posttreatment gains in face memory and social communication. The multisite randomized clinical trial compared the Experimental (EXP; SENSE Theatre) to an Active Control Condition (ACC; Tackling Teenage Training, TTT) at pretest, posttest, and follow-up.

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Article Synopsis
  • The study investigates the use of evoked potentials as potential biomarkers for clinical severity in rare neurodevelopmental disorders, specifically MECP2 duplication syndrome and FOXG1 syndrome, alongside previously studied conditions like Rett syndrome and CDKL5 deficiency disorder.* -
  • Researchers collected visual and auditory evoked potentials from participants across multiple sites, comparing them to age-matched individuals with other conditions to identify group-level differences and associations with clinical severity.* -
  • Findings indicated that visual evoked potentials (VEPs) were reduced in individuals with Rett syndrome, CDKL5 deficiency disorder, and MECP2 duplication syndrome, while auditory evoked potentials (AEPs) showed prolonged latency in MECP2 duplication and FOXG1 synd
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Objectives: The objective of this study was to investigate whether a brief speech-in-noise training with a remote microphone (RM) system (favorable listening condition) would contribute to enhanced post-training plasticity changes in the auditory system of school-age children.

Design: Before training, event-related potentials (ERPs) were recorded from 49 typically developing children, who actively identified two syllables in quiet and in noise (+5 dB signal-to-noise ratio [SNR]). During training, children completed the same syllable identification task as in the pre-training noise condition, but received feedback on their performance.

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Despite the high need for effective treatments for major depressive disorder (MDD), the development of novel medicines is hampered by clinical, genetic and biological heterogeneity, unclear links between symptoms and neural dysfunction, and tenuous biomarkers for clinical trial contexts of use. In this study, we examined the International Study to Predict Optimized Treatment in Depression (iSPOT-D) clinical trial database for new relationships between auditory event-related potential (ERP) responses, demographic features, and clinical symptoms and behavior, to inform strategies for biomarker-driven patient stratification that could be used to optimize future clinical trial design and drug development strategy in MDD. We replicate findings from previous analyses of the classic auditory oddball task in the iSPOT-D sample showing smaller than typical N1 and P300 response amplitudes and longer P300 latencies for target and standard stimuli in patients with MDD, suggesting altered bottom-up sensory and top-down attentional processes.

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Angelman syndrome (AS) is known to affect expressive and receptive communication abilities. This study examined individual differences in neural mechanisms underlying speech processing in children with AS (n = 24, M age = 10.01 years) and typical development (n = 30, M age = 10.

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Language comprehension requires the rapid retrieval and integration of contextually appropriate concepts ("semantic cognition"). Current neurobiological models of semantic cognition are limited by the spatial and temporal restrictions of single-modality neuroimaging and lesion approaches. This is a major impediment given the rapid sequence of processing steps that have to be coordinated to accurately comprehend language.

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Introduction: Objective evaluation of receptive communication abilities in nonspeaking individuals using standardized behavioral measures can be complicated by co-occurring intellectual disabilities and motor difficulties. Eye tracking during listening may offer an informative complementary approach to directly evaluate receptive language skills.

Method: This study examined feasibility of eye gaze measures as an index of spoken language comprehension in nonspeaking children and adults with Angelman syndrome (AS; n = 23) using a looking-while-listening procedure.

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Article Synopsis
  • CDKL5 deficiency disorder is a serious condition with no specific treatments, and the study aims to find reliable biomarkers to evaluate new therapies.
  • Researchers measured brain activity through visual and auditory evoked potentials and EEG in 26 individuals with the disorder and compared their results to typically developing peers.
  • The study found that people with CDKL5 deficiency had lower visual evoked potential amplitudes, and specific EEG features correlated with disease severity, especially the theta/delta ratio, which was the strongest predictor of clinical severity.
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Autism may be underdiagnosed in females because their social difficulties are often less noticeable. This study explored sex differences in automatic facial emotion processing in 45 adolescents with autism spectrum disorder (22 female, 23 male), age 10-16 years, performing active target detection task and Go/NoGo tasks where faces with positive and negative emotional expressions served as irrelevant distractors. The combined sample demonstrated more accurate performance on the target detection (response initiation) than the Go/NoGo task (response inhibition), replicating findings previously reported in typical participants.

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Difficulty engaging in reciprocal social interactions is a core characteristic of autism spectrum disorder. The mechanisms supporting effective dynamic real-time social exchanges are not yet well understood. This proof-of-concept hyperscanning electroencephalography study examined neural synchrony as the mechanism supporting interpersonal social interaction in 34 adolescents with autism spectrum disorder (50% female), age 10-16 years, paired with neurotypical confederates of similar age.

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Late-life depression (LLD) is a debilitating condition that is associated with poor response to antidepressant medications and deficits in cognitive performance. Nicotinic cholinergic stimulation has emerged as a potentially effective candidate to improve cognitive performance in patients with cognitive impairment. Previous studies of nicotinic stimulation in animal models and human populations with cognitive impairment led to examining potential cognitive and mood effects of nicotinic stimulation in older adults with LLD.

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Background: Sensory over-responsivity (SOR) refers to excessively intense and/or prolonged behavioral responses to environmental stimuli typically perceived as non-aversive. SOR is prevalent in several neurodevelopmental disorders, including chronic tic disorders (CTDs) and obsessive-compulsive disorder (OCD). Few studies have examined the extent and clinical correlates of SOR across disorders, limiting insights into the phenomenon's transdiagnostic clinical and biological relevance.

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Purpose Investigations into the nature of communication disorders in autistic individuals increasingly evaluate neural responses to speech stimuli. This integrative review aimed to consolidate the available data related to speech and language processing across levels of stimulus complexity (from single speech sounds to sentences) and to relate it to the current theories of autism. Method An electronic database search identified peer-reviewed articles using event-related potentials or magnetoencephalography to investigate auditory processing from single speech sounds to sentences in autistic children and adults varying in language and cognitive abilities.

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Developmental trends between 3 and 24 months were assessed in 194 normocephalic infants with prenatal Zika virus exposure. Bayley Scales of Infant and Toddler Development Screening Test-3rd Edition cognitive scores remained in the typical range. Communication skills developed at a slower rate suggesting that neurodevelopmental delays may emerge at older ages.

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Background: Angelman syndrome (AS) patients often respond to low glycemic index therapy to manage refractory seizures. These diets significantly affect quality of life and are challenging to implement. These formulations may have benefits in AS even in the absence of biomarkers suggesting ketosis.

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This review summarizes main applications of event-related potentials (ERPs) to the study of cognitive processes in persons with neurodevelopmental disorders, for whom traditional behavioral assessments may not be suitable. A brief introduction to the ERPs is followed by a review of empirical studies using passive ERP paradigms to address three main questions: characterizing individual differences, predicting risk for poor developmental outcomes, and documenting treatment effects in persons with neurodevelopmental disorders. Evidence across studies reveals feasibility of ERP methodology in a wide range of clinical populations and notes consistently stronger brain-behavior associations involving ERP measures of higher-order cognition compared with sensory-perceptual processes.

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