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Replicating thought suppression effects with the Think/No-Think paradigm (TNT) has failed in some studies investigating the phenomenon of below-baseline recall of suppressed stimuli. Attempts have been made to isolate factors that might explain inter-individual differences in suppression performance. Certain personality traits, whether associated with a pathological state or investigated in a community sample, have been shown to interfere with successful thought suppression and might be responsible for some of the negative results obtained in TNT studies. In the present study we investigate the influence of psychometric measures of depression and anxiety in a fairly large sample of healthy volunteers. We show that high brooding and anxious tendencies predict worse suppression performance. While no suppression was shown when investigating the TNT not taking the psychometric measures into account, including these two traits in the analysis resulted in a pattern of below-baseline recall only for low brooders and low anxious participants. We argue that inclusion of variables measuring personality traits is warranted using the TNT and that these variables already exert their influence at minimal levels of variance, significantly improving the interpretability of the results. Future research should therefore cautiously investigate potential confounding personality characteristics before analysing their data.

In this study, the neural correlates of error processing in adult patients with attention deficit hyperactivity disorder (ADHD) are to be investigated for the first time. Recent studies in children with ADHD suggested, with some inconsistencies, deficits in error processing. Based on an analogue study with students, we hypothesized that ADHD patients show reduced amplitudes in the event-related potential (ERP) of the Pe (error positivity) but normal amplitudes of the ERN (error-related negativity) after incorrect responses.In this study we investigated 34 adult ADHD patients and 34 healthy controls with a modified version of the Eriksen flanker task while recording the neural activity with 26 scalp EEG electrodes. Patients discontinued all medication at least 3 days prior to investigation. Age was included as a control variable for the statistical analyses.As hypothesized, we found reduced Pe amplitudes, but also reduced ERN values, in ADHD patients. Importantly, theses differences as well as the deficits in behavioural performance were mainly detectable in the younger subsample, but not in the elderly subsample. Our results indicate that adult ADHD patients are characterized by deficits in error processing, which vanish with age.

In this study, a variant of the n-back task was used to investigate electrophysiological correlates of top-down processes in visual-object working memory. Event-related potentials were used to replicate results concerning an attention related modulation of neural processes and to investigate the involvement of prefrontal cortex in this modulation. 16 healthy subjects executed an n-back task with sequentially presented faces and scenes. Attention was selectively directed to only one stimulus category. We found an enhancement of the N170 amplitudes for relevant stimuli compared to irrelevant or neutral stimuli. Late frontal amplitudes were stronger positive for relevant compared to neutral stimuli indicating selective attention processes of working memory. Evidence for selective inhibition was not found.

Patients suffering from dementia show altered functional brain activation patterns especially in prefrontal brain regions, as research suggests. The present study follows three aims: to replicate these findings, to investigate treatment effects when administering galantamine, and to put gender differences in focus. We compared 12 patients with dementia to 12 age- and gender-matched healthy subjects regarding changes in haemoglobin concentration in brain tissue while performing a verbal fluency task (VFT). Concentration changes of oxygenated (O(2)Hb) and deoxygenated (HHb) haemoglobin were measured by multi-channel near-infrared spectroscopy (NIRS), an easily applicable and non-invasive method of optical topography. In the patient group, measurement was repeated 4 and 8 weeks after starting treatment with galantamine. The results showed a reduced increase in O(2)Hb during task performance for patients compared to healthy controls. Furthermore, female subjects showed more pronounced activation in O(2)Hb as well as HHb compared to male subjects. Regarding treatment effects, no clear results could be obtained. In HHb, evidence for an entrainment effect was found. In the light of existing literature, the present study suggests an interaction of gender and age regarding brain activation patterns which should be aimed at in future investigations.