Ellen Greimel

Attentional Performance in Children and Adolescents with Tic Disorder and Co-Occurring Attention-Deficit/Hyperactivity Disorder: New Insights from a 2 × 2 Factorial Design Study

The aim of the present study was to investigate the effect of both tic disorder (TD) and attention-deficit/hyperactivity disorder (ADHD) on attentional functions. N = 96 children and adolescents participated in the study, including n = 21 subjects with TD, n = 23 subjects with ADHD, n = 25 subjects with TD+ADHD, and n = 27 controls. Attentional performance was tested based on four computerized attention tasks (sustained attention, divided attention, go/nogo and set shifting). The effect of TD as well as ADHD on attentional performance was tested using a 2 × 2 factorial approach. A diagnosis of TD had no negative impact on attentional functions but was associated with improved performance in the set shifting task. By contrast, regardless of a diagnosis of TD, subjects with ADHD were found to perform worse in the sustained attention, divided attention and go/nogo task. No interaction effect between the factors TD and ADHD was revealed for any of the attention measures. Our results add to findings from other areas of research, showing that in subjects with TD and ADHD, ADHD psychopathology is often the main source of impairment, whereas a diagnosis of TD has little or no impact on neuropsychological performance in most cases and even seems to be associated with adaptive mechanisms.

Attentional functions in children and adolescents with attention-deficit/ hyperactivity disorder with and without comorbid tic disorder

SummaryAlthough the coexistence of attention-deficit/hyperactivity disorder (ADHD) and tic disorder (TD) is common, the nature of association is yet not fully understood. Thus, the aim of the present study was to explore attentional dysfunction in children with pure ADHD compared to children with comorbid ADHD + TD. Three groups of 20 children each, aged 8–15 years with either ADHD, ADHD + chronic tic disorder or Tourette syndrome (ADHD + TD) and a healthy control group were compared in their performance on three computerized attention tasks. Tasks of sustained attention, selective attention and interference control were employed. In addition, parental ratings of ADHD symptom severity and behaviour problems were obtained. Both clinical groups were rated as equally inattentive, however, externalising symptoms were more severe in the ADHD group. Objective measures of attentional performance revealed differences between the groups: whereas the ADHD group was markedly impaired in sustaining attention and selective attention/inhibitory control, the ADHD + TD group only showed marginal deficits in selective attention/inhibitory control. Possible explanations for the superior performance of the comorbid group are discussed: In particular, the results may indicate that in some patients, the tic disorder produces behavioural symptoms of ADHD, but not the broad neurocognitive deficits that usually are associated with ADHD. Alternatively, compensatory neural mechanisms of TD patients may result in a better neuropsychological performance of comorbid patients relative to patients suffering from pure ADHD.

Neural mechanisms of encoding social and non-social context information in autism spectrum disorder.

Individuals with autism spectrum disorder (ASD) often fail to attach context to their memories and are specifically impaired in processing social aspects of contextual information. The aim of the present study was to investigate the modulatory influence of social vs. non-social context on neural mechanisms during encoding in ASD. Using event-related fMRI, 13 boys with ASD and 13 typically developing boys comparable for age and IQ were investigated during encoding of neutral objects presented either with a social (faces) or a non-social (houses) context. A memory paradigm was then applied to identify brain activation patterns associated with encoding of subsequently recollected versus non-recollected objects. On the behavioural level, no significant between-group differences emerged. In particular, no differential effects of context on memory performance were observed. Neurally, however, context-specific group differences were observed in several brain regions. During encoding of subsequently recollected objects presented with a face, ASD subjects (compared to controls) showed reduced neural activation in the bilateral inferior frontal gyrus, bilateral middle frontal gyrus and right inferior parietal lobule. Neural activation in the right inferior frontal gyrus was positively correlated with memory performance in controls, but negatively in ASD individuals. During encoding of subsequently non-recollected objects presented in the non-social context, ASD subjects showed increased activation in the dorsal MPFC. Our findings suggest that in ASD subjects, fronto-parietal brain regions subserving memory formation and the association of contextual information are activated atypically when a social context is presented at encoding. The data add to findings from related research fields indicating that in ASD, socioemotional impairment extends into domains beyond social cognition. Increased activation in the dorsal MPFC in ASD individuals might reflect supervisory cognitive processes related to the suppression of a distracting non-social context.

The temporal dynamics of coherent motion processing in autism spectrum disorder: Evidence for a deficit in the dorsal pathway

Individuals with autism spectrum disorder (ASD) show impairments in processing coherent motion which have been proposed to be linked to a general deficit in the dorsal visual pathway. However, few studies have investigated the neural mechanisms underlying coherent motion processing in ASD. Thus, the aim of this study was to further test the hypothesis of a dorsal pathway deficit in ASD using visual evoked potentials (VEPs). 16 children and adolescents with ASD and 12 typically developing controls were examined with VEPs elicited by a random dot kinematogram. After an initial experimental sequence, where subjects were presented randomly moving dots, a fraction of the dots moved coherently (dependent on the level of coherence, 20%, 40%, or 60% of the dots) to the left or right side. Subjects were asked to detect the direction of coherent motion via button press. On the behavioural level, no significant group differences emerged. On the neural level, coherently moving dots elicited a N200 followed by a late positive potential (P400). ASD subjects exhibited a reduced N200 amplitude compared to controls. Moreover, in the ASD group, a trend for a negative relationship between N200 amplitude and a measure of autistic pathology was revealed. The present study provides strong support of a dorsal stream deficiency in the disorder and renders alternative explanations for impaired coherent motion processing in ASD less likely. Together with findings from related research fields, our data indicate that deviances in the N200 during coherent motion perception might be fundamental to ASD.

Selbst- und Fremdbeurteilung der Empathie bei Jugendlichen mit Autismus

OBJECTIVE A deficit in empathy has repeatedly been described as a central feature of autistic disorders. However, little is known about how adolescents with autism evaluate their own empathic abilities, and how their parents judge these skills. The present study assesses affective components of empathy via both self-report and parental report. METHOD 18 boys with autism and 18 typically developing boys participated in the study. A German translation of the Bryant Index of Empathy was used for the self-assessment of empathy. Parents rated the empathic abilities of their sons using a German version of the Griffith Empathy Measure. Both questionnaires are comparable with regards to content and mainly tap into affective components of empathy. RESULTS Self-reports of empathy in adolescents with autism did not differ from controls. In contrast, parents of adolescents with autism judged their sons to be less empathic compared to parents of typically developing adolescents. CONCLUSIONS The discrepancy between unimpaired self-reported empathy and parental report of impaired empathy in adolescents with autism might result from their difficulties in effectively conveying empathic feelings to other people. Alternatively, the results may be explained by impaired introspection on inner experiences in individuals with autism.

Befunde zum menschlichen Spiegelneuronensystem bei Autismus: Eine kritische Übersicht funktioneller Bildgebungsstudien

Es mehren sich Hinweise, dass Menschen uber ein Spiegelneuronensystem verfugen, das fur das Verstandnis von Handlungen, fur Imitation und fur Empathie von groser Bedeutung sein konnte. Autistische Storungen gehen mit Beeintrachtigungen in der Imitation und Empathie einher. Die Annahme, dass diesen Beeintrachtigungen defizitare Spiegelneuronenmechanismen zugrunde liegen konnten, hat eine Reihe von Untersuchungen angeregt, die mittels bildgebender Methoden die Funktion des Spiegelneuronensystems bei Personen mit Autismus uberpruft haben. Basierend auf Annahmen und Erkenntnissen zu Spiegelneuronenmechanismen bei gesunden Kindern und Erwachsenen werden in der vorliegenden Arbeit die Ergebnisse dieser Studien zusammengefasst und kritisch diskutiert. Zudem werden mogliche klinische Implikationen der Befunde dargestellt.

Zurückweisungsempfindlichkeit bei Jugendlichen mit Depression

Objective Rejection sensitivity (RS) is defined as the disposition to anxiously expect rejection, to perceive it as likely, and to overreact to it. Former studies showed heightened RS in clinically depressed adults and identified it as a predictor for symptoms of depression in adolescents. However, to date there are no studies examining RS as a disposition in adolescents with clinical Depression. Method In the present study, we compared differences in RS and behavioral intentions in depressive and healthy adolescents after a rejection situation. We included n = 28 adolescents with depression and n = 32 healthy control participants between the ages of 12–17 and applied a German version of the Children’s Rejection Sensitivity Questionnaire “CRSQ”. Results It was found that, compared to controls, depressive adolescents show higher RS, are more anxious about rejection, and rate the likelihood of being rejected higher. Furthermore, adolescents with depression more often indicated to resign to rejection and blame themselves for it than their healthy counterparts. Conclusions Our results are in concordance with the clinical picture and with cognitive theories of the disorder. In future studies, it would be important to examine whether corresponding interventions can have a positive impact on the course of the disease.

State or trait? Auditory event-related potentials in adolescents with current and remitted major depression

Objective: Event‐related potential (ERP) studies have revealed abnormal neurophysiological patterns underlying selective attention in patients with Major Depression (MD). Only few included both patients in acute and remitted state to address the question whether these abnormalities are state‐ or trait‐ dependent and none focused on adolescent MD. Thus, the aim of our study was to address this question in an adolescent sample. Methods: 22 adolescents with acute MD, 20 adolescents with remitted MD (rMD) and 32 healthy controls (HC) performed a standard two‐tone auditory oddball task while ERPs (N100, P200, N200, P300) were collected. Results: Adolescents with rMD showed a reduced N200 amplitude to target tones across frontal, central and parietal recording sites. Adolescents with MD exhibited a reduced N200 amplitude to targets in the frontal region compared to HC. No differences emerged between rMD and the MD group. Conclusions: The reduced N200 amplitude in adolescents with rMD and MD presumably reflects difficulties in stimulus classification and response selection. Our results indicate that this neurophysiological characteristic is a trait marker of adolescent depression. HIGHLIGHTSAdolescents with remitted and acute depression performed an auditory oddball task.A reduction of the N200 amplitude was evident in the acute and remitted state.Results suggest that a reduced N200 is a trait marker of adolescent depression.

Sex differences in the neural underpinnings of social and monetary incentive processing during adolescence

The brain’s reward system undergoes major changes during adolescence, and an increased reactivity to social and nonsocial incentives has been described as a typical feature during this transitional period. Little is known whether there are sex differences in the brain’s responsiveness to social or monetary incentives during adolescence. The aim of this event-related potential (ERP) study was to compare the neurophysiological underpinnings of monetary and social incentive processing in adolescent boys versus girls. During ERP recording, 38 adolescents (21 females, 17 males; 13–18 years) completed an incentive delay task comprising (a) a reward versus punishment condition and (b) social versus monetary incentives. The stimulus-preceding negativity (SPN) was recorded during anticipation of reward and punishment, and the feedback P3 (fP3) along with the feedback-related negativity (FRN) after reward/punishment delivery. During anticipation of social punishment, adolescent boys compared with girls exhibited a reduced SPN. After delivery, male adolescents exhibited higher fP3 amplitudes to monetary compared with social incentives, whereas fP3 amplitudes in girls were comparable across incentive types. Moreover, whereas in boys fP3 responses were higher in rewards than in punishment trials, no such difference was evident in girls. The results indicate that adolescent boys show a reduced neural responsivity in the prospect of social punishment. Moreover, the findings imply that, once the incentive is obtained, adolescent boys attribute a relatively enhanced motivational significance to monetary incentives and show a relative hyposensitivity to punishment. The findings might contribute to our understanding of sex-specific vulnerabilities to problem behaviors related to incentive processing during adolescence.