Memory performance of an individual (within the age range: 50-55 years old) showing superior memory abilities (protagonist PR) was compared to an age- and education-matched reference group in a historical facts ("famous events") retrieval task.

In social contexts, facial expressions are dynamic in nature and vary rapidly in relation to situational requirements. However, there are very few fMRI studies using dynamic emotional stimuli. The aim of this study was (1) to introduce and evaluate a new stimulus database of static and dynamic emotional facial expressions according to arousal and recognizability investigated by a rating by both participants of the present fMRI study and by an external sample of 30 healthy women, (2) to examine the neural networks involved in emotion perception of static and dynamic facial stimuli separately, and (3) to examine the impact of motion on the emotional processing of dynamic compared to static face stimuli. A total of 16 females participated in the present fMRI study performing a passive emotion perception task including static and dynamic faces of neutral, happy and disgusted expressions. Comparing dynamic stimuli to static faces indicated enhanced emotion-specific brain activation patterns in the parahippocampal gyrus (PHG) including the amygdala (AMG), fusiform gyrus (FG), superior temporal gyrus (STG), inferior frontal gyrus (IFG), and occipital and orbitofrontal cortex (OFC). These regions have been discussed to be associated with emotional memory encoding, the perception of threat, facial identity, biological motion, the mirror neuron system, an increase of emotional arousal, and reward processing, respectively. Post hoc ratings of the dynamic stimuli revealed a better recognizability in comparison to the static stimuli. In conclusion, dynamic facial expressions might provide a more appropriate approach to examine the processing of emotional face perception than static stimuli.

Childhood obesity is a rising problem caused in part by unhealthy food choices. Food choices are based on a neural value signal encoded in the ventromedial prefrontal cortex, and self-control involves modulation of this signal by the dorsolateral prefrontal cortex (dlPFC). We determined the effects of development, body mass (BMI Cole score) and body mass history on the neural correlates of healthy food choice in children. 141 children (aged 10-17y) from Germany, Hungary and Sweden were scanned with fMRI while performing a food choice task. Afterwards health and taste ratings of the foods were collected. In the food choice task children were asked to consider the healthiness or tastiness of the food or to choose naturally. Overall, children made healthier choices when asked to consider healthiness. However, children who had a higher weight gain per year chose less healthy foods when considering healthiness but not when choosing naturally. Pubertal development stage correlated positively while current body mass correlated negatively with dlPFC activation when accepting foods. Pubertal development negatively and current body mass positively influenced the effect of considering healthiness on activation of brain areas involved in salience and motivation. In conclusion, children in earlier stages of pubertal development and children with a higher body weight exhibited less activation in the dlPFC, which has been implicated in self-control during food choice. Furthermore, pubertal development and body mass influenced neural responses to a health cue in areas involved in salience and motivation. Thus, these findings suggest that children in earlier stages of pubertal development, children with a higher body mass gain and children with overweight may possibly be less susceptible to healthy eating interventions that rely on self-control or that highlight health aspects of food.

Though we can almost pre-attentively categorize the valence of facial expressions, we experience emotional ambiguity when confronted with facial expressions in a context with incongruent emotional information. We simultaneously presented interfering background colors during forced-choice categorizations of negative (fear), neutral and positive (happy) expressions. Conflicting information induced strong and differential interference effects on a behavioral level which was mirrored in comparable activations on a neuronal level. Besides a common fronto-parietal attention network which was activated during interference resolution, we found differential interference effects for facial expressions. Incongruent trials with neutral expressions induced a distinct activation pattern in ventral visual regions particularly involved in deeper analysis for both the task-relevant facial expressions (fusiform (FFA) and occipital face area (OFA)) and the task-irrelevant color (V4). Compared to neutral expressions, incongruent trials including either negative or positive expressions elicited attenuated interference effects. Unlike incongruent trials with positive facial expressions which showed only sparse activation in frontal cortex, interference resolution during processing of negative facial expressions resulted in specific activations in regions (V3a, MT(+), STS) which might be involved in processing of implicit dynamics of negative expressions. Thus, functional activations in visual processing regions might specifically be related to processing demands of different expressions.

The present study aimed at identifying the neural responses associated with the incidental processing of the emotional valence of single words using event-related functional magnetic resonance imaging (fMRI). Twenty right-handed participants performed a visual lexical decision task, discriminating between nouns and orthographically and phonologically legal nonwords. Positive, neutral and negative word categories were matched for frequency, number and frequency of orthographic neighbors, number of letters and imageability. Response times and accuracy data differed significantly between positive and neutral, and positive and negative words respectively, thus, replicating the findings of a pilot study. Words showed distributed, mainly left hemisphere activations, indicating involvement of a neural network responsible for semantic word knowledge. The neuroimaging data further revealed areas in left orbitofrontal gyrus and bilateral inferior frontal gyrus with greater activation to emotional than to neutral words. These brain regions are known to be involved in processing semantic and emotional information. Furthermore, distinct activations associated with positive words were observed in bilateral middle temporal and superior frontal gyrus, known to support semantic retrieval, and a distributed network, namely anterior and posterior cingulate gyrus, lingual gyrus and hippocampus when comparing positive and negative words. The latter areas were previously associated with explicit and not incidental processing of the emotional meaning of words and emotional memory retrieval. Thus, the results are discussed in relation to models of processing semantic and episodic emotional information.

Prodigies are individuals with exceptional mental abilities. How is it possible that some of these people mentally calculate exponentiations with high accuracy and speed? We examined CP, a mental calculation prodigy, and a control group of 11 normal calculators for moderate mental arithmetic tasks. CP has additionally been tested for exceptionally difficult exponentiations. We hypothesized that, if CP would activate similar brain regions as controls for both moderate and very difficult tasks, his special exceptional abilities could rather be explained by neuroplastic changes as a result of obsessive practice than by unusual mental strategies and/or neurocognitive mechanisms. For very difficult exponentiation tasks, CP showed activation patterns in brain regions adjacent to those, which were activated for moderate task calculation by both CP and control participants. We concluded, therefore, that CP's exceptional calculation performance might rather be based on neuroplastic changes substantially caused by years of daily hours of training combined with excellent working memory capabilities and not on the recruitment of additional brain mechanisms. Furthermore, but considering that only one prodigy was compared with a control group, results of the present study imply that the neural substrate, which is potentially necessary to enhance specific skills dramatically by positively motivated excessive mental training, might be present in every healthy individual.

We investigated if single and double conflicts are processed separately in different brain regions and if they are differentially vulnerable to TMS perturbation. Fifteen human volunteers performed a single (Flanker or Simon) conflict task or a double (Flanker and Simon) conflict task in a combined functional Magnetic Resonance Imaging (fMRI) and Transcranial Magnetic Stimulation (TMS) study. The fMRI approach aimed at localizing brain regions involved in interference resolution induced by single Flanker (stimulus-stimulus, S-S) and Simon (stimulus-response, S-R) conflicts as well as regions involved in the double conflict condition. The data revealed a distinct activation in the right intraparietal sulcus (IPS) for Flanker interference and in the right middle frontal gyrus (MFG) for the double interference condition. The causal functional role of these brain regions was then examined in the same volunteers by using offline TMS over right IPS and right MFG. TMS perturbation of the right IPS increased the Flanker effect, but had no effect in the Simon or double conflict condition. In contrast, perturbation of the right MFG had no effect on any of the conflict types. These findings suggest a causal role of the right IPS in the processing of the single conflict of Flanker (stimulus-stimulus) interference.

A recent functional magnetic resonance imaging (fMRI) study by our group demonstrated that dynamic emotional faces are more accurately recognized and evoked more widespread patterns of hemodynamic brain responses than static emotional faces. Based on this experimental design, the present study aimed at investigating the spatio-temporal processing of static and dynamic emotional facial expressions in 19 healthy women by means of multi-channel electroencephalography (EEG), event-related potentials (ERP) and fMRI-constrained regional source analyses. ERP analysis showed an increased amplitude of the LPP (late posterior positivity) over centro-parietal regions for static facial expressions of disgust compared to neutral faces. In addition, the LPP was more widespread and temporally prolonged for dynamic compared to static faces of disgust and happiness. fMRI constrained source analysis on static emotional face stimuli indicated the spatio-temporal modulation of predominantly posterior regional brain activation related to the visual processing stream for both emotional valences when compared to the neutral condition in the fusiform gyrus. The spatio-temporal processing of dynamic stimuli yielded enhanced source activity for emotional compared to neutral conditions in temporal (e.g., fusiform gyrus), and frontal regions (e.g., ventromedial prefrontal cortex, medial and inferior frontal cortex) in early and again in later time windows. The present data support the view that dynamic facial displays trigger more information reflected in complex neural networks, in particular because of their changing features potentially triggering sustained activation related to a continuing evaluation of those faces. A combined fMRI and EEG approach thus provides an advanced insight to the spatio-temporal characteristics of emotional face processing, by also revealing additional neural generators, not identifiable by the only use of an fMRI approach.

The present study examined whether feature-based cueing affects early or late stages of flanker conflict processing using EEG and fMRI. Feature cues either directed participants' attention to the upcoming colour of the target or were neutral. Validity-specific modulations during interference processing were investigated using the N200 event-related potential (ERP) component and BOLD signal differences. Additionally, both data sets were integrated using an fMRI-constrained source analysis. Finally, the results were compared with a previous study in which spatial instead of feature-based cueing was applied to an otherwise identical flanker task. Feature-based and spatial attention recruited a common fronto-parietal network during conflict processing. Irrespective of attention type (feature-based; spatial), this network responded to focussed attention (valid cueing) as well as context updating (invalid cueing), hinting at domain-general mechanisms. However, spatially and non-spatially directed attention also demonstrated domain-specific activation patterns for conflict processing that were observable in distinct EEG and fMRI data patterns as well as in the respective source analyses. Conflict-specific activity in visual brain regions was comparable between both attention types. We assume that the distinction between spatially and non-spatially directed attention types primarily applies to temporal differences (domain-specific dynamics) between signals originating in the same brain regions (domain-general localization).

The issue of how and where arithmetic operations are represented in the brain has been addressed in numerous studies. Lesion studies suggest that a network of different brain areas are involved in mental calculation. Neuroimaging studies have reported inferior parietal and lateral frontal activations during mental arithmetic using tasks of different complexities and using different operators (addition, subtraction, etc.). Indeed, it has been difficult to compare brain activation across studies because of the variety of different operators and different presentation modalities used. The present experiment examined fMRI-BOLD activity in participants during calculation tasks entailing different arithmetic operations -- addition, subtraction, multiplication and division -- of different complexities. Functional imaging data revealed a common activation pattern comprising right precuneus, left and right middle and superior frontal regions during all arithmetic operations. All other regional activations were operation specific and distributed in prominently frontal, parietal and central regions when contrasting complex and simple calculation tasks. The present results largely confirm former studies suggesting that activation patterns due to mental arithmetic appear to reflect a basic anatomical substrate of working memory, numerical knowledge and processing based on finger counting, and derived from a network originally related to finger movement. We emphasize that in mental arithmetic research different arithmetic operations should always be examined and discussed independently of each other in order to avoid invalid generalizations on arithmetics and involved brain areas.

Usually, incongruent flanker stimuli provoke conflict processing whereas congruent flankers should facilitate task performance. Various behavioral studies reported improved or even absent conflict processing with correctly oriented selective attention. In the present study we attempted to reinvestigate these behavioral effects and to disentangle neuronal activity patterns underlying the attentional cueing effect taking advantage of a combination of the high temporal resolution of Electroencephalographic (EEG) and the spatial resolution of functional magnetic resonance imaging (fMRI). Data from 20 participants were acquired in different sessions per method. We expected the conflict-related N200 event-related potential (ERP) component and areas associated with flanker processing to show validity-specific modulations. Additionally, the spatio-temporal dynamics during cued flanker processing were examined using an fMRI-constrained source analysis approach. In the ERP data we found early differences in flanker processing between validity levels. An early centro-parietal relative positivity for incongruent stimuli occurred only with valid cueing during the N200 time window, while a subsequent fronto-central negativity was specific to invalidly cued interference processing. The source analysis additionally pointed to separate neural generators of these effects. Regional sources in visual areas were involved in conflict processing with valid cueing, while a regional source in the anterior cingulate cortex (ACC) seemed to contribute to the ERP differences with invalid cueing. Moreover, the ACC and precentral gyrus demonstrated an early and a late phase of congruency-related activity differences with invalid cueing. We discuss the first effect to reflect conflict detection and response activation while the latter more likely originated from conflict monitoring and control processes during response competition.

Previous studies reported heterogeneous findings in working memory tasks when examining differences between correct recognition (targets) and correct rejection (non-targets). In the present study, twenty human participants completed a delayed match-to-sample task in two separate functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) sessions. Targets and non-target items were presented at different within-trial positions. We used fMRI-constrained source analysis to investigate the spatio-temporal neuronal dynamics of probe processing. Probe type-related differences were modulated by position in the trial or by the ratio of target stimuli to non-target stimuli at different trial positions. fMRI-constrained source analysis revealed a temporal pattern of source activities starting in occipital and temporal brain regions, followed by a simultaneous engagement of parietal and frontal brain regions and a later activity of a source in pre-SMA (supplementary motor area). Source activities demonstrated a specific involvement of left fusiform gyrus in the non-target condition compared to the target condition that might be associated with mental imagination of the target stimulus during non-target probe processing. Source activities, furthermore, showed the anterior cingulate to be particularly involved in target processing compared to non-target processing before response execution and the pre-SMA before and during response execution. These brain areas appear to be activated in different stages of conflict managing operations due to a lower stimulus frequency of target trials compared to non-target trials at different target positions in the present design.

Executive control is a human ability that allows to overcome automatic stimulus-response mappings and to act appropriate in the context of a task where the selection of relevant stimuli and the suppression of interfering information are crucial. In order to address the question which brain areas are involved in the detection and processing of two simultaneously operating sources of interference derived from a spatial incompatibility task, we used functional MRI to contrast neural activity related to a double conflict situation to single incompatibility conditions. Results show signal increase of left dorsolateral prefrontal cortex when monitoring simultaneously presented conflict. There was no additional activity in the medial prefrontal cortex or anterior cingulate cortex although these regions are expected to play an important role in all types of conflict monitoring. Further analyses of conflict resolution and post-error adaptation pointed to different underlying functional mechanisms. While the resolution of high conflict was associated with rostral ACC activation, the post-error adaptation reflecting activity during post-error trials suggests a specific medial and lateral prefrontal network which was functionally distinct from conflict-related activity. Our results also suggest a major role for the basal ganglia during error detection and resolution.

The present study aimed at characterizing the neural correlates of conflict resolution in two variations of the Simon effect. We introduced two different Simon tasks where subjects had to identify shapes on the basis of form-from-motion perception (FFMo) within a randomly moving dot field, while (1) motion direction (motion-based Simon task) or (2) stimulus location (location-based Simon task) had to be ignored. Behavioral data revealed that both types of Simon tasks induced highly significant interference effects. Using event-related fMRI, we could demonstrate that both tasks share a common cluster of activated brain regions during conflict resolution (pre-supplementary motor area (pre-SMA), superior parietal lobule (SPL), and cuneus) but also show task-specific activation patterns (left superior temporal cortex in the motion-based, and the left fusiform gyrus in the location-based Simon task). Although motion-based and location-based Simon tasks are conceptually very similar (Type 3 stimulus-response ensembles according to the taxonomy of [Kornblum, S., Stevens, G. (2002). Sequential effects of dimensional overlap: findings and issues. In: Prinz, W., Hommel., B. (Eds.), Common mechanism in perception and action. Oxford University Press, Oxford, pp. 9-54]) conflict resolution in both tasks results in the activation of different task-specific regions probably related to the different sources of task-irrelevant information. Furthermore, the present data give evidence those task-specific regions are most likely to detect the relationship between task-relevant and task-irrelevant information.

Neuroimaging data suggest that pediatric overweight and obesity are associated with morphological alterations in gray matter (GM) brain structures, but previous studies using mainly voxel-based morphometry (VBM) showed inconsistent results. Here, we aimed to examine the relationship between youth obesity and the volume of predefined reward system structures using magnetic resonance (MR) volumetry. We also aimed to complement volumetry with VBM-style analysis.

Results of recent computational modelling studies suggest that a general function of the striatum in human cognition is related to shifting decision criteria in selection processes. We used functional magnetic resonance imaging (fMRI) in 21 healthy subjects to examine the hemodynamic responses when subjects shift their response criterion on a trial-by-trial basis in the lexical decision paradigm. Trial-by-trial criterion setting is obtained when subjects respond faster in trials following a word trial than in trials following nonword trials - irrespective of the lexicality of the current trial. Since selection demands are equally high in the current trials, we expected to observe neural activations that are related to response criterion shifting. The behavioural data show sequential effects with faster responses in trials following word trials compared to trials following nonword trials, suggesting that subjects shifted their response criterion on a trial-by-trial basis. The neural responses revealed a signal increase in the striatum only in trials following word trials. This striatal activation is therefore likely to be related to response criterion setting. It demonstrates a role of the striatum in shifting decision criteria in visual word recognition, which cannot be attributed to pure error-related processing or the selection of a preferred response.