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1.
Clin Neurophysiol ; 150: 205-215, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37104910

RESUMEN

OBJECTIVE: Impaired reward processing has been found in individuals with anxiety, but also major depressive disorder (MDD). Here, we studied neural correlates of reward anticipation and processing in a sample of youth with severe social phobia and comorbid depression (SP/MDD) and investigated the specific contribution of SP and MDD symptoms. METHODS: 15 affected, unmedicated and 25 typically developing (TD) youth completed a monetary gambling task, which included a positive, negative and ambiguous reward condition. Event-related potentials representing cue processing (cue P300), reward anticipation (stimulus preceding negativity, SPN), reward sensitivity (feedback related negativity, FRN) and reward processing (reward P300) were analysed. RESULTS: Reduced amplitudes of the right hemispheric (r)SPN and reward P300 were observed in SP/MDD compared to TD. Within the SP/MDD group SP symptoms correlated with larger rSPN, and FRN amplitudes. MDD symptoms correlated with smaller rSPN and smaller FRN positive-negative difference wave. CONCLUSIONS: Reward anticipation and feedback processing are reduced in SP/MDD. Higher SP symptoms are associated with stronger neural activation during reward anticipation and reward sensitivity. Depressive symptoms are associated with decreased reward anticipation and sensitivity. Findings are in line with the theory of heightened vigilance in anxiety and blunted reward processing due to anhedonia in MDD. SIGNIFICANCE: The study results can inform behavioural interventions for SP and MDD.


Asunto(s)
Trastorno Depresivo Mayor , Fobia Social , Humanos , Adolescente , Electroencefalografía , Depresión , Potenciales Evocados/fisiología , Recompensa
2.
Eur Child Adolesc Psychiatry ; 32(3): 501-512, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34596762

RESUMEN

Interpretation bias and dysfunctional social assumptions are proposed to play a pivotal role in the development and maintenance of social phobia (SP), especially in youth. In this study, we aimed to investigate disorder-specific implicit assumptions of rejection and implicit interpretation bias in youth with severe, chronic SP and healthy controls (CG). Twenty-seven youth with SP in inpatient/day-care treatment (M age = 15.6 years, 74% female) and 24 healthy controls (M age = 15.7 years, 54% female) were included. The Implicit Association Test (IAT) and the Affect Misattribution Procedure (AMP) were completed to assess implicit assumptions and interpretation bias related to the processing of social and affective stimuli. No group differences were observed for the IAT controlling for depressive symptoms in the analyses. However, group differences were found regarding interpretation bias (p = .017, η2p = .137). Correlations between implicit scores and explicit questionnaire results were medium to large in the SP group (r =|.28| to |.54|, pall ≤ .05), but lower in the control group (r =|.04| to |.46|, pall ≤ .05). Our results confirm the finding of an interpretation bias in youth SP, especially regarding the implicit processing of faces, whereas implicit dysfunctional social assumptions of being rejected do not seem to be specific for SP. Future research should investigate the causal relationship of assumptions/interpretation bias and SP.


Asunto(s)
Fobia Social , Humanos , Femenino , Adolescente , Masculino , Encuestas y Cuestionarios
3.
J Neural Transm (Vienna) ; 129(11): 1339-1352, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36029418

RESUMEN

Studies using transcranial magnetic stimulation with simultaneous electroencephalography (TMS-EEG) revealed an imbalance between cortical excitation and inhibition (E/I) in the dorsolateral prefrontal cortex (DLPFC) in depression. As adolescence is a developmental period with an increase in depression prevalence and profound neural changes, it is crucial to study the relationship between depression and cortical excitability in adolescence. We aimed to investigate the cortical excitability of the DLPFC in adolescents with depression and a dependency of the TMS-evoked potential N100 on the depression severity. 36 clinical patients (12-18 years of age; 21 females) with a major depressive episode were assessed twice in a longitudinal design: shortly after admission (T0) and after six weeks of intervention (T1). GABA-B-mediated cortical inhibition in the left and right DLPFC, as assessed by the N100, was recorded with EEG. Significantly higher depression scores were reported at T0 compared to T1 (p < 0.001). N100 amplitudes were significantly increased (i.e., more negative) at T0 compared to T1 (p = 0.03). No significant hemispheric difference was found in the N100 component. The correlation between the difference in depression severity and the difference in N100 amplitudes (T0-T1) obtained during stimulation of the left DLPFC did not remain significant after correction for testing in both hemispheres. Higher N100 amplitudes during a state of greater depression severity are suggestive of an E/I imbalance in the DLPFC in adolescents with an acute depressive episode. The N100 reduction potentially reflects a normalization of DLPFC over inhibition in association with decreased depressive symptomatology, indicating severity dependency.


Asunto(s)
Trastorno Depresivo Mayor , Adolescente , Depresión , Corteza Prefontal Dorsolateral , Electroencefalografía , Potenciales Evocados/fisiología , Femenino , Humanos , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal , Ácido gamma-Aminobutírico
4.
Front Psychiatry ; 13: 781409, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35774088

RESUMEN

Sensory features in autism spectrum disorder (ASD) have received increasing interest in clinical work and research during the recent years. With the Sensory Perception Quotient (SPQ), Tavasolli and colleagues have produced a self-rating scale for adults with ASD that measures sensory hyper-sensitivity in different sensory modalities, without also tapping cognitive or motivational aspects that precede or follow autistic sensory experiences. Here, we present the results of a translation of the SPQ to German and its short version as well as their validation in samples of autistic or neuro-typical participants. We, furthermore, present the psychometric properties and validities of Tavasolli's original SPQ-short version as well as an alternative short version based on different psychometric item-selection criteria. We can show here that our alternative SPQ-short version, overlapping with the original short-version in 61% of its items, exhibits superior reliabilities, reasonable concurrent validities with other related measures. It, furthermore, exhibits excellent differentiation between autistic and non-autistic samples, underscoring its utility as a screening instrument in research and a clinical instrument to supplement the ASD diagnostic process.

5.
Neuroimage ; 259: 119407, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-35752414

RESUMEN

Somatosensory short-term memory is essential for object recognition, sensorimotor learning, and, especially, Braille reading for people who are blind. This study examined how visual sensory deprivation and a compensatory focus on somatosensory information influences memory processes in this domain. We measured slow cortical negativity developing during short-term tactile memory maintenance (tactile contralateral delay activity, tCDA) in frontal and somatosensory areas while a sample of 24 sighted participants and 22 participants who are blind completed a tactile change-detection task where varying loads of Braille pin patterns served as stimuli. Auditory cues, appearing at varying latencies between sample arrays, could be used to reduce memory demands during maintenance. Participants who are blind (trained Braille readers) outperformed sighted participants behaviorally. In addition, while task-related frontal activation featured in both groups, participants who are blind uniquely showed higher tCDA amplitudes specifically over somatosensory areas. The site specificity of this component's functional relevance in short-term memory maintenance was further supported by somatosensory tCDA amplitudes first correlating across the whole sample with behavioral performance, and secondly showing sensitivity to varying memory load. The results substantiate sensory recruitment models and provide new insights into the effects of visual sensory deprivation on tactile processing. Between-group differences in the interplay between frontal and somatosensory areas during somatosensory maintenance also suggest that efficient maintenance of complex tactile stimuli in short-term memory is primarily facilitated by lateralized activity in somatosensory cortex.


Asunto(s)
Memoria a Corto Plazo , Corteza Somatosensorial , Ceguera , Electroencefalografía , Humanos , Memoria a Corto Plazo/fisiología , Lectura , Corteza Somatosensorial/fisiología , Tacto/fisiología
6.
Clin Neurophysiol ; 135: 37-50, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35026539

RESUMEN

OBJECTIVE: Long-latency trigeminal somatosensory evoked potentials (SSEPs) have not been sufficiently studied regarding their topography and lateralization. SSEPs are hypothesized to contribute to the evoked potentials after transcranial magnetic stimulation (TMS). This study focused on trigeminal SSEPs with latencies > 100 ms, potentially overlapping with TMS-evoked N100. METHODS: In 14 healthy subjects, the trigeminus was electrically stimulated on the left and right forehead, and time-course, topography, and lateralization of trigeminal SSEPs were examined in 64-channel electroencephalogram (EEG). SSEPs were then compared to TMS-evoked potentials when TMS was applied to the left and right dorsolateral prefrontal cortex. RESULTS: Trigeminal stimulation produced a somatosensory N140 with topographic maximum over centroparietal electrodes with larger amplitudes contra- than ipsilaterally to the stimulation. Contralateral potentials after TMS were partly comparable in their topography but differed in latencies. CONCLUSIONS: SSEPs generated by electrical stimulation of the trigeminus occurred over somatosensory areas with a contralateral lateralization. Therefore, contralateral potentials after TMS should be interpreted with caution, as they may include somatosensory components. SIGNIFICANCE: The topography and lateralization of long-latency trigeminal SSEPs should be considered in future TMS-EEG designs.


Asunto(s)
Potenciales Evocados Somatosensoriales , Estimulación Magnética Transcraneal/métodos , Nervio Trigémino/fisiología , Adulto , Femenino , Humanos , Masculino , Corteza Prefrontal/fisiología , Tiempo de Reacción , Estimulación Magnética Transcraneal/normas
7.
Depress Anxiety ; 39(1): 26-36, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34617644

RESUMEN

BACKGROUND: Specific phobias have the highest prevalence among anxiety disorders. Cognitive control involving the dorsolateral prefrontal cortex (DLPFC) is crucial for coping abilities in anxiety disorders. However, there is little research on the DLPFC in specific phobia. METHODS: Using transcranial magnetic stimulation (TMS), we investigated the TMS-evoked potential component N100 in the DLPFC at rest and while watching emotional expressions. The TMS-evoked N100 provides a parameter for gamma-aminobutyric acid (GABA)-B-mediated cortical inhibition. Twenty-two drug-free subjects with specific phobia (21 females and 1 male) were compared with 26 control subjects (23 females and 3 males) regarding N100 in the DLPFC at rest and during an emotional 1-back task with fearful, angry, and neutral facial expressions. RESULTS: At rest, we found reduced N100 amplitudes in the specific phobia compared with the control group. Furthermore, the specific phobia group showed a further reduction in N100 amplitude when memorizing fearful compared with neutral facial expressions. CONCLUSION: There appears to be a decrease in GABA-B-mediated inhibition in the DLPFC in subjects with a specific phobia at rest. This decrease was more pronounced under emotional activation by exposure to fearful facial expressions, pointing towards additional state effects of emotional processing on inhibitory function in the DLPFC.


Asunto(s)
Expresión Facial , Trastornos Fóbicos , Corteza Prefontal Dorsolateral , Electroencefalografía , Femenino , Humanos , Masculino , Corteza Prefrontal , Estimulación Magnética Transcraneal
8.
Front Neurosci ; 15: 709605, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34177461

RESUMEN

[This corrects the article DOI: 10.3389/fnins.2021.623692.].

9.
Front Neurosci ; 15: 616667, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33790732

RESUMEN

INTRODUCTION: Transcranial magnetic stimulation (TMS)-evoked potentials (TEPs) allow for probing cortical functions in health and pathology. However, there is uncertainty whether long-latency TMS-evoked potentials reflect functioning of the targeted cortical area. It has been suggested that components such as the TMS-evoked N100 are stereotypical and related to nonspecific sensory processes rather than transcranial effects of the changing magnetic field. In contrast, TEPs that vary according to the targeted brain region and are systematically lateralized toward the stimulated hemisphere can be considered to reflect activity in the stimulated brain region resulting from transcranial electromagnetic induction. METHODS: TMS with concurrent 64-channel electroencephalography (EEG) was sequentially performed in homologous areas of both hemispheres. One sample of healthy adults received TMS to the dorsolateral prefrontal cortex; another sample received TMS to the temporo-occipital cortex. We analyzed late negative TEP deflections corresponding to the N100 component in motor cortex stimulation. RESULTS: TEP topography varied according to the stimulation target site. Long-latency negative TEP deflections were systematically lateralized (higher in ipsilateral compared to contralateral electrodes) in electrodes over the stimulated brain region. A calculation that removes evoked components that are not systematically lateralized relative to the stimulated hemisphere revealed negative maxima located around the respective target sites. CONCLUSION: TEPs contain long-latency negative components that are lateralized toward the stimulated hemisphere and have their topographic maxima at the respective stimulation sites. They can be differentiated from co-occurring components that are invariable across different stimulation sites (probably reflecting coactivation of peripheral sensory afferences) according to their spatiotemporal patterns. Lateralized long-latency TEP components located at the stimulation site likely reflect activity evoked in the targeted cortex region by direct transcranial effects and are therefore suitable for assessing cortical functions.

10.
Front Neurosci ; 15: 623692, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33732105

RESUMEN

Transcranial magnetic stimulation (TMS) with simultaneous electroencephalography applied to the primary motor cortex provides two parameters for cortical excitability: motor evoked potentials (MEPs) and TMS-evoked potentials (TEPs). This study aimed to evaluate the effects of systematic coil shifts on both the TEP N100 component and MEPs in addition to the relationship between both parameters. In 12 healthy adults, the center of a standardized grid was fixed above the hot spot of the target muscle of the left primary motor cortex. Twelve additional positions were arranged in a quadratic grid with positions between 5 and 10 mm from the hot spot. At each of the 13 positions, TMS single pulses were applied. The topographical maximum of the resulting N100 was located ipsilateral and slightly posterior to the stimulation site. A source analysis revealed an equivalent dipole localized more deeply than standard motor cortex coordinates that could not be explained by a single seeded primary motor cortex dipole. The N100 topography might not only reflect primary motor cortex activation, but also sum activation of the surrounding cortex. N100 amplitude and latency decreased significantly during stimulation anterior-medial to the hot spot although MEP amplitudes were smaller at all other stimulation sites. Therefore, N100 amplitudes might be suitable for detecting differences in local cortical excitability. The N100 topography, with its maximum located posterior to the stimulation site, possibly depends on both anatomical characteristics of the stimulated cortex and differences in local excitability of surrounding cortical areas. The less excitable anterior cortex might contribute to a more posterior maximum. There was no correlation between N100 and MEP amplitudes, but a single-trial analysis revealed a trend toward larger N100 amplitudes in trials with larger MEPs. Thus, functionally efficient cortical excitation might increase the probability of higher N100 amplitudes, but TEPs are also generated in the absence of MEPs.

11.
Eur Neuropsychopharmacol ; 29(8): 960-970, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31280897

RESUMEN

Attention deficit hyperactivity disorder (ADHD) has been linked to abnormal functioning of cortical motor areas such as the supplementary motor area, the premotor cortex and primary motor cortex (MI). The Bereitschaftspotential (BP) and lateralized readiness potential (LRP) are movement-related potentials generated by cortical motor areas. We hypothesized that the BP and LRP would be altered in children with ADHD. A group of 17 children with ADHD (mean age: 11.5 ±â€¯1.9 years) and a control group of 16 typically developing children (mean age: 12.2 ±â€¯2.0 years) performed movements at self-chosen irregular intervals while a 64-channel DC-EEG was registered. BP and LRP were calculated from the EEG. The ADHD group had significantly lower and on average positive BP amplitudes at Cz. In agreement with age-dependent maturation effects the LRP had a positive polarity in both groups, but lower amplitudes were found in the ADHD group without medication. The control group showed a mid-central negativity and a positivity over motor areas contra-lateral to the side of movement, whereas no negativity over Cz and a more diffuse positivity was found in the ADHD group. LRP group differences diminished after MPH administration as indicated by an interaction between group and time of measurement/medication. The cortical motor system shows altered functioning during movement preparation and initiation in children affected by ADHD. Positive Bereitschaftspotential polarities may represent delayed cortical maturation. Group differences of LRP were pharmacologically modulated by the catecholaminergic agent MPH.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Encéfalo/fisiopatología , Variación Contingente Negativa , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Estimulantes del Sistema Nervioso Central/uso terapéutico , Niño , Variación Contingente Negativa/efectos de los fármacos , Estudios Transversales , Electroencefalografía , Electromiografía , Femenino , Humanos , Masculino , Metilfenidato/uso terapéutico , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología
12.
J Neural Transm (Vienna) ; 123(8): 925-35, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27177879

RESUMEN

Brain maturation from childhood to adulthood is associated with changes in structural and functional connectivity between remote brain regions. Altered connectivity plays an important role in the pathology of autism spectrum disorder (ASD), a severe neurodevelopmental disorder. ASD is associated with abnormal brain development and structurally altered interhemispheric connections. Cortico-cortical connectivity can be studied by a combination of transcranial magnetic stimulation (TMS) with concurrent EEG (TMS-EEG). TMS-evoked Interhemispheric Signal Propagation (ISP) is a correlate of interhemispheric connectivity related to the microstructure of the corpus callosum (CC). We used TMS-EEG to measure ISP in 22 ASD subjects (10-21 years) and 22 typically developing control subjects (9-19 years). We expected (1) maturational changes of ISP from childhood to young adulthood and also (2) reduced interhemispheric signal transfer in ASD. ISP was positively correlated with age in both ASD and typically developing control subjects. No difference in ISP between ASD and typically developing controls was found. Our findings demonstrate maturation of effective interhemispheric connectivity during adolescence. As ISP is related to the microstructure of the CC, the developmental change of ISP likely reflects maturation of the CC during the second life decade. The results support ISP as a valid parameter reflecting functional interhemispheric connectivity. Our results do not support a global deficit of interhemispheric connectivity in ASD.


Asunto(s)
Trastorno del Espectro Autista/patología , Trastorno del Espectro Autista/fisiopatología , Mapeo Encefálico , Cuerpo Calloso/fisiopatología , Potenciales Evocados Motores/fisiología , Lateralidad Funcional/fisiología , Adolescente , Niño , Electroencefalografía , Femenino , Humanos , Masculino , Procesamiento de Señales Asistido por Computador , Estimulación Magnética Transcraneal , Adulto Joven
13.
Autism Res ; 9(10): 1036-1045, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26788924

RESUMEN

Neuropeptides such as oxytocin (OXT) are known facilitators of social behavior across species. Variants of the OXT receptor gene (OXTR) have been tested for association with autism spectrum disorder (ASD) across manifold ethnicities, yielding both positive and negative findings. A recent meta-analysis, comprising 16 single nucleotide polymorphisms (SNPs), has corroborated the implication of OXTR in the etiology of ASD. Here, we genotyped and tested two additional variants (rs237889 and rs237897) for association with ASD in two German predominantly high-functioning ASD samples. We found nominal over-transmission (OR = 1.48, CI95 = 1.06-2.08, P = 0.022) for the minor A allele of variant rs237889G>A in sample 1 (N = 135 complete parent-offspring trios, 29 parent child duos), but not in sample 2 (362 trios, 69 duos). Still, in a meta-analysis comprising four different studies including the two unreported German data sets (N = 542 families), this finding was confirmed (OR = 1.12; CI95 = 1.01-1.24, random effects P = 0.012). In addition, carriers of the minor risk allele rs237889-A showed significantly increased severity scores, as assessed through the autism diagnostic interview - revised (ADI-R), with highly significant increases in social interaction deficits. Our results corroborate the implication of common OXTR variants in the etiology of ASD. There is a need for functional studies to delineate the neurobiological implications of this and other association findings. (172/250). Autism Res 2016, 9: 1036-1045. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.


Asunto(s)
Trastorno del Espectro Autista/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Oxitocina/genética , Alelos , Niño , Genotipo , Humanos
14.
PLoS One ; 9(2): e88585, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24520402

RESUMEN

Attention-deficit/hyperactivity disorder (ADHD) is often accompanied by problems in social behaviour, which are sometimes similar to some symptoms of autism-spectrum disorders (ASD). However, neuronal mechanisms of ASD-like deficits in ADHD have rarely been studied. The processing of biological motion-recently discussed as a marker of social cognition-was found to be disrupted in ASD in several studies. Thus in the present study we tested if biological motion processing is disrupted in ADHD. We used 64-channel EEG and spatio-temporal source analysis to assess event-related potentials associated with human motion processing in 21 children and adolescents with ADHD and 21 matched typically developing controls. On the behavioural level, all subjects were able to differentiate between human and scrambled motion. But in response to both scrambled and biological motion, the N200 amplitude was decreased in subjects with ADHD. After a spatio-temporal dipole analysis, a human motion specific activation was observable in occipital-temporal regions with a reduced and more diffuse activation in ADHD subjects. These results point towards neuronal determined alterations in the processing of biological motion in ADHD.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Potenciales Evocados/fisiología , Movimiento (Física) , Percepción Visual/fisiología , Adolescente , Conducta , Estudios de Casos y Controles , Niño , Trastornos Generalizados del Desarrollo Infantil/fisiopatología , Humanos , Estimulación Luminosa
15.
Hum Genet ; 133(6): 781-92, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24442360

RESUMEN

Autism spectrum disorders (ASD) are heterogeneous disorders with a high heritability and complex genetic architecture. Due to the central role of the fragile X mental retardation gene 1 protein (FMRP) pathway in ASD we investigated common functional variants of ASD risk genes regulating FMRP. We genotyped ten SNPs in two German patient sets (N = 192 and N = 254 families, respectively) and report association for rs7170637 (CYFIP1; set 1 and combined sets), rs6923492 (GRM1; combined sets), and rs25925 (CAMK4; combined sets). An additional risk score based on variants with an odds ratio (OR) >1.25 in set 1 and weighted by their respective log transmitted/untransmitted ratio revealed a significant effect (OR 1.30, 95 % CI 1.11-1.53; P = 0.0013) in the combined German sample. A subsequent meta-analysis including the two German samples, the "Strict/European" ASD subsample of the Autism Genome Project (1,466 families) and a French case/control (541/366) cohort showed again association of rs7170637-A (OR 0.85, 95 % CI 0.75-0.96; P = 0.007) and rs25925-G (OR 1.31, 95 % CI 1.04-1.64; P = 0.021) with ASD. Functional analyses revealed that these minor alleles predicted to alter splicing factor binding sites significantly increase levels of an alternative mRNA isoform of the respective gene while keeping the overall expression of the gene constant. These findings underpin the role of ASD candidate genes in postsynaptic FMRP regulation suggesting that an imbalance of specific isoforms of CYFIP1, an FMRP interaction partner, and CAMK4, a transcriptional regulator of the FMRP gene, modulates ASD risk. Both gene products are related to neuronal regulation of synaptic plasticity, a pathomechanism underlying ASD and may thus present future targets for pharmacological therapies in ASD.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina/genética , Trastornos Generalizados del Desarrollo Infantil/genética , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adolescente , Alelos , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina/metabolismo , Niño , Trastornos Generalizados del Desarrollo Infantil/etnología , Trastornos Generalizados del Desarrollo Infantil/metabolismo , Trastornos Generalizados del Desarrollo Infantil/patología , Preescolar , Femenino , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/metabolismo , Regulación de la Expresión Génica , Técnicas de Genotipaje , Humanos , Masculino , Plasticidad Neuronal/genética , Unión Proteica , Factores de Riesgo , Transducción de Señal , Población Blanca
16.
Soc Cogn Affect Neurosci ; 9(8): 1214-22, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23887808

RESUMEN

Atypical visual processing of biological motion contributes to social impairments in autism spectrum disorders (ASD). However, the exact temporal sequence of deficits of cortical biological motion processing in ASD has not been studied to date. We used 64-channel electroencephalography to study event-related potentials associated with human motion perception in 17 children and adolescents with ASD and 21 typical controls. A spatio-temporal source analysis was performed to assess the brain structures involved in these processes. We expected altered activity already during early stimulus processing and reduced activity during subsequent biological motion specific processes in ASD. In response to both, random and biological motion, the P100 amplitude was decreased suggesting unspecific deficits in visual processing, and the occipito-temporal N200 showed atypical lateralization in ASD suggesting altered hemispheric specialization. A slow positive deflection after 400 ms, reflecting top-down processes, and human motion-specific dipole activation differed slightly between groups, with reduced and more diffuse activation in the ASD-group. The latter could be an indicator of a disrupted neuronal network for biological motion processing in ADS. Furthermore, early visual processing (P100) seems to be correlated to biological motion-specific activation. This emphasizes the relevance of early sensory processing for higher order processing deficits in ASD.


Asunto(s)
Encéfalo/fisiopatología , Trastornos Generalizados del Desarrollo Infantil/fisiopatología , Potenciales Evocados Visuales/fisiología , Percepción de Movimiento/fisiología , Percepción Social , Adolescente , Niño , Electroencefalografía , Humanos , Masculino , Pruebas Neuropsicológicas , Estimulación Luminosa
17.
Hum Brain Mapp ; 34(5): 1102-14, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-22965654

RESUMEN

Pattern recognition approaches to the analysis of neuroimaging data have brought new applications such as the classification of patients and healthy controls within reach. In our view, the reliance on expensive neuroimaging techniques which are not well tolerated by many patient groups and the inability of most current biomarker algorithms to accommodate information about prior class frequencies (such as a disorder's prevalence in the general population) are key factors limiting practical application. To overcome both limitations, we propose a probabilistic pattern recognition approach based on cheap and easy-to-use multi-channel near-infrared spectroscopy (fNIRS) measurements. We show the validity of our method by applying it to data from healthy controls (n = 14) enabling differentiation between the conditions of a visual checkerboard task. Second, we show that high-accuracy single subject classification of patients with schizophrenia (n = 40) and healthy controls (n = 40) is possible based on temporal patterns of fNIRS data measured during a working memory task. For classification, we integrate spatial and temporal information at each channel to estimate overall classification accuracy. This yields an overall accuracy of 76% which is comparable to the highest ever achieved in biomarker-based classification of patients with schizophrenia. In summary, the proposed algorithm in combination with fNIRS measurements enables the analysis of sub-second, multivariate temporal patterns of BOLD responses and high-accuracy predictions based on low-cost, easy-to-use fNIRS patterns. In addition, our approach can easily compensate for variable class priors, which is highly advantageous in making predictions in a wide range of clinical neuroimaging applications.


Asunto(s)
Mapeo Encefálico , Reconocimiento Visual de Modelos/fisiología , Probabilidad , Espectroscopía Infrarroja Corta , Corteza Visual/fisiología , Adulto , Femenino , Lateralidad Funcional , Hemoglobinas/metabolismo , Humanos , Masculino , Memoria a Corto Plazo , Persona de Mediana Edad , Modelos Psicológicos , Mioglobina/metabolismo , Estimulación Luminosa , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Esquizofrenia/clasificación , Esquizofrenia/diagnóstico , Vocabulario , Adulto Joven
18.
Psychiatry Res ; 194(3): 378-384, 2011 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-22079657

RESUMEN

Altered prefrontal brain activity (e.g. hypofrontality) during cognitive tasks such as working memory is a core neuroimaging marker in unipolar (UNI) and bipolar (BI) depression. The present study investigated for the first time UNI (n=16) and BI patients (n=14) in a working memory task including different processes (storage and matching) and components (object and spatial visual) with functional near-infrared spectroscopy (fNIRS) over the prefrontal cortex. In healthy controls (n=15) comparable to both patient groups, changes of oxygenated and deoxygenated haemoglobin indicated increased ventro-lateral, dorso-lateral prefrontal and superior frontal cortex activity for object and spatial visual working memory storage as compared to the control condition. In contrast, both patient groups showed diminished brain activity in all working memory conditions. Results revealed unspecific deficits that did not allow the differentiation between unipolar and bipolar depression in dependence of working memory processes or components. However, fNIRS can be considered as a valid, easy manageable, low cost and rapid tool for measuring (diminished) prefrontal cortex functions.


Asunto(s)
Mapeo Encefálico , Depresión , Hemoglobinas/metabolismo , Trastornos de la Memoria/etiología , Memoria a Corto Plazo/fisiología , Corteza Prefrontal/metabolismo , Adulto , Depresión/complicaciones , Depresión/metabolismo , Depresión/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Tiempo de Reacción , Espectroscopía Infrarroja Corta
19.
Int J Neuropsychopharmacol ; 14(7): 887-97, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21281558

RESUMEN

Cognitive deficits in tasks involving the prefrontal cortex such as working memory or verbal fluency are a key component of schizophrenia. This led to the hypofrontality hypothesis of schizophrenia, which is widely accepted even though molecular underpinnings are elusive. While disturbances of glutamatergic neurotransmission might play a role, other components have rarely been investigated. Recently, the promoter region of nitric oxide (NO) synthase-I (NOS-I, encoded by the gene NOS1), impacting on prefrontal glutamate transmission, has repeatedly been associated with schizophrenia. We thus tested whether an associated schizophrenia risk variant (rs41279104), leading to reduced expression of the transcript, influences prefrontal brain functioning. Forty-three patients suffering from chronic schizophrenia and 44 controls were genotyped for NOS1 rs41279104 and investigated by means of functional near-infrared spectroscopy (fNIRS), while completing a working-memory task (2-back test) and a verbal fluency test (VFT). After matching for genotype, behavioural and brain activation data of 26 patients and 28 comparable controls were correlated to rs41279104. Healthy controls showed significant activation of large parts of the lateral prefrontal cortex during both tasks, whereas task-related changes in oxygenation were significantly reduced in patients. Schizophrenia patients also performed worse in both tasks. The NOS1 schizophrenia risk genotype rs41279104 AA/AG was associated with slower reaction time in the 2-back task, as well as with reduced right-hemispheric activation of the frontal cortex for VFT in patients only. Our fNIRS data extend previous studies suggesting disturbed prefrontal functioning in schizophrenia and suggest that genetic variation of NOS1 has a role in cognitive dysfunction, probably by mediating glutamatergic tone.


Asunto(s)
Óxido Nítrico Sintasa de Tipo I/genética , Óxido Nítrico Sintasa de Tipo I/fisiología , Corteza Prefrontal/fisiopatología , Esquizofrenia/genética , Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Adulto , Mapeo Encefálico/métodos , Estudios de Casos y Controles , Trastornos del Conocimiento/complicaciones , Trastornos del Conocimiento/genética , Trastornos del Conocimiento/fisiopatología , Femenino , Lóbulo Frontal/fisiopatología , Genotipo , Humanos , Masculino , Memoria a Corto Plazo/fisiología , Persona de Mediana Edad , Polimorfismo Genético , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Esquizofrenia/complicaciones , Espectroscopía Infrarroja Corta/métodos , Conducta Verbal/fisiología
20.
Arch Gen Psychiatry ; 68(4): 361-8, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21135315

RESUMEN

CONTEXT: Although psychiatric disorders are, to date, diagnosed on the basis of behavioral symptoms and course of illness, the interest in neurobiological markers of psychiatric disorders has grown substantially in recent years. However, current classification approaches are mainly based on data from a single biomarker, making it difficult to predict disorders characterized by complex patterns of symptoms. OBJECTIVE: To integrate neuroimaging data associated with multiple symptom-related neural processes and demonstrate their utility in the context of depression by deriving a predictive model of brain activation. DESIGN: Two groups of participants underwent functional magnetic resonance imaging during 3 tasks probing neural processes relevant to depression. SETTING: Participants were recruited from the local population by use of advertisements; participants with depression were inpatients from the Department of Psychiatry, Psychosomatics, and Psychotherapy at the University of Wuerzburg, Wuerzburg, Germany. PARTICIPANTS: We matched a sample of 30 medicated, unselected patients with depression by age, sex, smoking status, and handedness with 30 healthy volunteers. MAIN OUTCOME MEASURE: Accuracy of single-subject classification based on whole-brain patterns of neural responses from all 3 tasks. RESULTS: Integrating data associated with emotional and affective processing substantially increases classification accuracy compared with single classifiers. The predictive model identifies a combination of neural responses to neutral faces, large rewards, and safety cues as nonredundant predictors of depression. Regions of the brain associated with overall classification comprise a complex pattern of areas involved in emotional processing and the analysis of stimulus features. CONCLUSIONS: Our method of integrating neuroimaging data associated with multiple, symptom-related neural processes can provide a highly accurate algorithm for classification. The integrated biomarker model shows that data associated with both emotional and reward processing are essential for a highly accurate classification of depression. In the future, large-scale studies will need to be conducted to determine the practical applicability of our algorithm as a biomarker-based diagnostic aid.


Asunto(s)
Biomarcadores , Mapeo Encefálico/métodos , Depresión/diagnóstico , Depresión/fisiopatología , Desempeño Psicomotor/fisiología , Adulto , Algoritmos , Señales (Psicología) , Expresión Facial , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Recompensa
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