@article{GoepelBiehlKissleretal.2011,
  author    = {Goepel, Johanna and Biehl, Stefanie C. and Kissler, Johanna and Paul-Jordanov, Isabelle},
  title     = {Pro- and antisaccades in children elicited by visual and acoustic targets - does modality matter?},
  series = {BMC Pediatrics},
  volume    = {11},
  journal   = {BMC Pediatrics},
  number    = {116},
  doi       = {10.1186/1471-2431-11-116},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141807},
  pages     = {1-8},
  year      = {2011},
  abstract  = {Background: Children are able to inhibit a prepotent reaction to suddenly arising visual stimuli, although this skill is not yet as pronounced as it is in adulthood. However, up to now the inhibition mechanism to acoustic stimuli has been scarcely investigated Methods: Reflexive (prosaccade) and inhibitory (antisaccade) responses to visual and acoustic targets were examined with an eye tracker system in 31 children between seven and twelve years of age using a gap-overlap task and two target eccentricities. Results: Acoustically cued saccades had longer reaction times than visually cued saccades. A gap effect (i.e., shorter reaction time in the gap than the overlap condition) was only found for visually elicited saccades, whereas an eccentricity effect (i.e., faster saccades to more laterally presented targets - 12 degrees vs. 6 degrees or rather 90 degrees vs. 45 degrees) was only present in the acoustic condition. Longer reaction times of antisaccades compared to prosaccades were found only in the visual task. Across both tasks the typical pattern of elevated error rates in the antisaccade condition was found. Antisaccade errors declined with age, indicating an ongoing development of inhibitory functions. Conclusions: The present results lay the ground for further studies of acoustically triggered saccades in typically as well as atypically developing children and it might thus be possible to upgrade physiological diagnostic tools.},
  language  = {en}
}
@article{BiehlMerzDresleretal.2016,
  author    = {Biehl, Stefanie C. and Merz, Christian J. and Dresler, Thomas and Heupel, Julia and Reichert, Susanne and Jacob, Christian P. and Deckert, J{\"u}rgen and Herrmann, Martin J.},
  title     = {Increase or Decrease of fMRI Activity in Adult Attention Deficit/ Hyperactivity Disorder: Does It Depend on Task Difficulty?},
  series = {International Journal of Neuropsychopharmacology},
  volume    = {19},
  journal   = {International Journal of Neuropsychopharmacology},
  number    = {10},
  doi       = {10.1093/ijnp/pyw049},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147551},
  pages     = {pyw049},
  year      = {2016},
  abstract  = {Background: Attention deficit/hyperactivity disorder has been shown to affect working memory, and fMRI studies in children and adolescents with attention deficit/hyperactivity disorder report hypoactivation in task-related attentional networks. However, studies with adult attention deficit/hyperactivity disorder patients addressing this issue as well as the effects of clinically valid methylphenidate treatment are scarce. This study contributes to closing this gap. Methods: Thirty-five adult patients were randomized to 6 weeks of double-blind placebo or methylphenidate treatment. Patients completed an fMRI n-back working memory task both before and after the assigned treatment, and matched healthy controls were tested and compared to the untreated patients. Results: There were no whole-brain differences between any of the groups. However, when specified regions of interest were investigated, the patient group showed enhanced BOLD responses in dorsal and ventral areas before treatment. This increase was correlated with performance across all participants and with attention deficit/hyperactivity disorder symptoms in the patient group. Furthermore, we found an effect of treatment in the right superior frontal gyrus, with methylphenidate-treated patients exhibiting increased activation, which was absent in the placebo-treated patients. Conclusions: Our results indicate distinct activation differences between untreated adult attention deficit/hyperactivity disorder patients and matched healthy controls during a working memory task. These differences might reflect compensatory efforts by the patients, who are performing at the same level as the healthy controls. We furthermore found a positive effect of methylphenidate on the activation of a frontal region of interest. These observations contribute to a more thorough understanding of adult attention deficit/hyperactivity disorder and provide impulses for the evaluation of therapy-related changes.},
  language  = {en}
}
@article{BiehlDreslerReifetal.2011,
  author    = {Biehl, Stefanie C. and Dresler, Thomas and Reif, Andreas and Scheuerpflug, Peter and Deckert, J{\"u}rgen and Herrmann, Martin J.},
  title     = {Dopamine Transporter (DAT1) and Dopamine Receptor D4 (DRD4) Genotypes Differentially Impact on Electrophysiological Correlates of Error Processing},
  series = {PLoS One},
  volume    = {6},
  journal   = {PLoS One},
  number    = {12},
  doi       = {10.1371/journal.pone.0028396},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137930},
  pages     = {e28396},
  year      = {2011},
  abstract  = {Recent studies as well as theoretical models of error processing assign fundamental importance to the brain's dopaminergic system. Research about how the electrophysiological correlates of error processing—the error-related negativity (ERN) and the error positivity (Pe)—are influenced by variations of common dopaminergic genes, however, is still relatively scarce. In the present study, we therefore investigated whether polymorphisms in the DAT1 gene and in the DRD4 gene, respectively, lead to interindividual differences in these error processing correlates. One hundred sixty participants completed a version of the Eriksen Flanker Task while a 26-channel EEG was recorded. The task was slightly modified in order to increase error rates. During data analysis, participants were split into two groups depending on their DAT1 and their DRD4 genotypes, respectively. ERN and Pe amplitudes after correct responses and after errors as well as difference amplitudes between errors and correct responses were analyzed. We found a differential effect of DAT1 genotype on the Pe difference amplitude but not on the ERN difference amplitude, while the reverse was true for DRD4 genotype. These findings are in line with predictions from theoretical models of dopaminergic transmission in the brain. They furthermore tie results from clinical investigations of disorders impacting on the dopamine system to genetic variations known to be at-risk genotypes.},
  language  = {en}
}
@article{BiehlEhlisMuelleretal.2013,
  author    = {Biehl, Stefanie C. and Ehlis, Ann-Christine and M{\"u}ller, Laura D. and Niklaus, Andrea and Pauli, Paul and Herrmann, Martin J.},
  title     = {The impact of task relevance and degree of distraction on stimulus processing},
  series = {BMC Neuroscience},
  journal   = {BMC Neuroscience},
  doi       = {10.1186/1471-2202-14-107},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97271},
  year      = {2013},
  abstract  = {Background The impact of task relevance on event-related potential amplitudes of early visual processing was previously demonstrated. Study designs, however, differ greatly, not allowing simultaneous investigation of how both degree of distraction and task relevance influence processing variations. In our study, we combined different features of previous tasks. We used a modified 1-back task in which task relevant and task irrelevant stimuli were alternately presented. The task irrelevant stimuli could be from the same or from a different category as the task relevant stimuli, thereby producing high and low distracting task irrelevant stimuli. In addition, the paradigm comprised a passive viewing condition. Thus, our paradigm enabled us to compare the processing of task relevant stimuli, task irrelevant stimuli with differing degrees of distraction, and passively viewed stimuli. EEG data from twenty participants was collected and mean P100 and N170 amplitudes were analyzed. Furthermore, a potential connection of stimulus processing and symptoms of attention deficit hyperactivity disorder (ADHD) was investigated. Results Our results show a modulation of peak N170 amplitudes by task relevance. N170 amplitudes to task relevant stimuli were significantly higher than to high distracting task irrelevant or passively viewed stimuli. In addition, amplitudes to low distracting task irrelevant stimuli were significantly higher than to high distracting stimuli. N170 amplitudes to passively viewed stimuli were not significantly different from either kind of task irrelevant stimuli. Participants with more symptoms of hyperactivity and impulsivity showed decreased N170 amplitudes across all task conditions. On a behavioral level, lower N170 enhancement efficiency was significantly correlated with false alarm responses. Conclusions Our results point to a processing enhancement of task relevant stimuli. Unlike P100 amplitudes, N170 amplitudes were strongly influenced by enhancement and enhancement efficiency seemed to have direct behavioral consequences. These findings have potential implications for models of clinical disorders affecting selective attention, especially ADHD.},
  language  = {en}
}