"Fact versus Fiction – How paratextual information shapes our reading processes"

Our life is full of stories: some of them depict real-life events and were reported, e.g. in the daily news or in autobiographies, whereas other stories, as often presented to us in movies and novels, are fictional. However, we have only little insights in the neurocognitive processes underlying the reading of factual as compared to fictional contents. We investigated the neurocognitive effects of reading short narratives, labeled to be either factual or fictional. Reading in a factual mode engaged an activation pattern suggesting an action-based reconstruction of the events depicted in a story. This process seems to be past-oriented and leads to shorter reaction times at the behavioral level. In contrast, the brain activation patterns corresponding to reading fiction seem to reflect a constructive simulation of what might have happened. This is in line with studies on imagination of possible past or future events.

Diminishing parochialism in intergroup conflict by disrupting the right temporo-parietal junction.

Individuals react to violation of social norms by outgroup members differently than to transgressions of those same norms by ingroup members: namely outgroup perpetrators are punished much more harshly than ingroup perpetrators. This parochial punishment pattern has been observed and extensively studied in social psychology and behavioral economics. Despite progress in recent years, however, little is known about the neural underpinnings of this intergroup bias. Here, we demonstrate by means of transcranial magnetic stimulation (TMS) that the transient disruption of the right, but not the left temporo-parietal junction (TPJ), reduces parochial punishment in a third-party punishment paradigm with real social groups. Moreover, we show that this observed TMS effect on parochial punishment is mediated by a classical punishment motive, i.e. retaliation. Finally, our data suggests that a change in perspective-taking might be the underlying mechanism that explains the impact of right TPJ disruption on retaliation motivation and parochial punishment. These findings provide the first causal evidence that the right TPJ plays a pivotal role in the implementation of parochial behaviors.

Neural patterns underlying social comparisons of personal performance

Humans often evaluate their abilities by comparing their personal performance with that of others. For this process, it is critical whether the comparison turns out in one's favor or against it. Here, we investigate how social comparisons of performance are encoded and integrated on the neural level. We collected functional magnetic resonance images while subjects answered questions in a knowledge quiz that was related to their profession. After each question, subjects received a feedback about their personal performance, followed by a feedback about the performance of a reference group who had been quizzed beforehand. Based on the subjects' personal performance, we divided trials in downward and upward comparisons. We found that upward comparisons correlated with activity in the dorsolateral prefrontal cortex and the anterior insula. Downward comparisons were associated with increased activation in the ventral striatum (VS), the medial orbitofrontal cortex and the ventral anterior cingulate cortex (ACC). The extent to which subjects outperformed the reference group modulated the activity in the VS and in the dorsal ACC. We suggest that the co-activation of the VS and the dorsal ACC contributes to the integration of downward comparisons into the evaluation of personal performance.

Neural representation and clinically relevant moderators of individualised self-criticism in healthy subjects

Many people routinely criticise themselves. While self-criticism is largely unproblematic for most individuals, depressed patients exhibit excessive self-critical thinking, which leads to strong negative affects. We used functional magnetic resonance imaging in healthy subjects (N = 20) to investigate neural correlates and possible psychological moderators of self-critical processing. Stimuli consisted of individually selected adjectives of personally negative content and were contrasted with neutral and negative non-self-referential adjectives. We found that confrontation with self-critical material yielded neural activity in regions involved in emotions (anterior insula/hippocampus-amygdala formation) and in anterior and posterior cortical midline structures, which are associated with self-referential and autobiographical memory processing. Furthermore, contrasts revealed an extended network of bilateral frontal brain areas. We suggest that the co-activation of superior and inferior lateral frontal brain regions reflects the recruitment of a frontal top-down pathway, representing cognitive reappraisal strategies for dealing with evoked negative affects. In addition, activation of right superior frontal areas was positively associated with neuroticism and negatively associated with cognitive reappraisal. Although these findings may not be specific to negative stimuli, they support a role for clinically relevant personality traits in successful regulation of emotion during confrontation with self-critical material.

Violence-related PTSD and neural activation when seeing emotionally charged male-female interactions.

Post-traumatic stress disorder (PTSD) is a disorder that involves impaired regulation of the fear response to traumatic reminders. This study tested how women with male-perpetrated interpersonal violence-related PTSD (IPV-PTSD) differed in their brain activation from healthy controls (HC) when exposed to scenes of male-female interaction of differing emotional content. Sixteen women with symptoms of IPV-PTSD and 19 HC participated in this study. During magnetic resonance imaging, participants watched a stimulus protocol of 23 different 20 s silent epochs of male-female interactions taken from feature films, which were neutral, menacing or prosocial. IPV-PTSD participants compared with HC showed (i) greater dorsomedial prefrontal cortex (dmPFC) and dorsolateral prefrontal cortex (dlPFC) activation in response to menacing vs prosocial scenes and (ii) greater anterior cingulate cortex (ACC), right hippocampus activation and lower ventromedial prefrontal cortex (vmPFC) activty in response to emotional vs neutral scenes. The fact that IPV-PTSD participants compared with HC showed lower activity of the ventral ACC during emotionally charged scenes regardless of the valence of the scenes suggests that impaired social perception among IPV-PTSD patients transcends menacing contexts and generalizes to a wider variety of emotionally charged male-female interactions.

Neural correlates of wishful thinking.

Wishful thinking (WT) implies the overestimation of the likelihood of desirable events. It occurs for outcomes of personal interest, but also for events of interest to others we like. We investigated whether WT is grounded on low-level selective attention or on higher level cognitive processes including differential weighting of evidence or response formation. Participants in our MRI study predicted the likelihood that their favorite or least favorite team would win a football game. Consistent with expectations, favorite team trials were characterized by higher winning odds. Our data demonstrated activity in a cluster comprising parts of the left inferior occipital and fusiform gyri to distinguish between favorite and least favorite team trials. More importantly, functional connectivities of this cluster with the human reward system were specifically involved in the type of WT investigated in our study, thus supporting the idea of an attention bias generating WT. Prefrontal cortex activity also distinguished between the two teams. However, activity in this region and its functional connectivities with the human reward system were altogether unrelated to the degree of WT reflected in the participants' behavior and may rather be related to social identification, ensuring the affective context necessary for WT to arise.

The power of emotional valence – from cognitive to affective processes in reading

The comprehension of stories requires the reader to imagine the cognitive and affective states of the characters. The content of many stories is unpleasant, as they often deal with conflict, disturbance or crisis. Nevertheless, unpleasant stories can be liked and enjoyed. In this fMRI study, we used a parametric approach to examine (1) the capacity of increasing negative valence of story contents to activate the mentalizing network (cognitive and affective theory of mind, ToM), and (2) the neural substrate of liking negatively valenced narratives. A set of 80 short narratives was compiled, ranging from neutral to negative emotional valence. For each story mean rating values on valence and liking were obtained from a group of 32 participants in a prestudy, and later included as parametric regressors in the fMRI analysis. Another group of 24 participants passively read the narratives in a three Tesla MRI scanner. Results revealed a stronger engagement of affective ToM-related brain areas with increasingly negative story valence. Stories that were unpleasant, but simultaneously liked, engaged the medial prefrontal cortex (mPFC), which might reflect the moral exploration of the story content. Further analysis showed that the more the mPFC becomes engaged during the reading of negatively valenced stories, the more coactivation can be observed in other brain areas related to the neural processing of affective ToM and empathy.

Disturbed cortico–amygdalar functional connectivity as pathophysiological correlate of working memory deficits in bipolar affective disorder

Patients suffering from bipolar affective disorder show deficits in working memory functions. In a previous functional magnetic resonance imaging study, we observed an abnormal hyperactivity of the amygdala in bipolar patients during articulatory rehearsal in verbal working memory. In the present study, we investigated the dynamic neurofunctional interactions between the right amygdala and the brain systems that underlie verbal working memory in both bipolar patients and healthy controls. In total, 18 euthymic bipolar patients and 18 healthy controls performed a modified version of the Sternberg item-recognition (working memory) task. We used the psychophysiological interaction approach in order to assess functional connectivity between the right amygdala and the brain regions involved in verbal working memory. In healthy subjects, we found significant negative functional interactions between the right amygdala and multiple cortical brain areas involved in verbal working memory. In comparison with the healthy control subjects, bipolar patients exhibited significantly reduced functional interactions of the right amygdala particularly with the right-hemispheric, i.e., ipsilateral, cortical regions supporting verbal working memory. Together with our previous finding of amygdala hyperactivity in bipolar patients during verbal rehearsal, the present results suggest that a disturbed right-hemispheric “cognitive–emotional” interaction between the amygdala and cortical brain regions underlying working memory may be responsible for amygdala hyperactivation and affects verbal working memory (deficits) in bipolar patients.

Spatial cognition, body representation and affective processes: the role of vestibular information beyond ocular reflexes and control of posture

A growing number of studies in humans demonstrate the involvement of vestibular information in tasks that are seemingly remote from well-known functions such as space constancy or postural control. In this review article we point out three emerging streams of research highlighting the importance of vestibular input: (1) Spatial Cognition: Modulation of vestibular signals can induce specific changes in spatial cognitive tasks like mental imagery and the processing of numbers. This has been shown in studies manipulating body orientation (changing the input from the otoliths), body rotation (changing the input from the semicircular canals), in clinical findings with vestibular patients, and in studies carried out in microgravity. There is also an effect in the reverse direction; top-down processes can affect perception of vestibular stimuli. (2) Body Representation: Numerous studies demonstrate that vestibular stimulation changes the representation of body parts, and sensitivity to tactile input or pain. Thus, the vestibular system plays an integral role in multisensory coordination of body representation. (3) Affective Processes and Disorders: Studies in psychiatric patients and patients with a vestibular disorder report a high comorbidity of vestibular dysfunctions and psychiatric symptoms. Recent studies investigated the beneficial effect of vestibular stimulation on psychiatric disorders, and how vestibular input can change mood and affect. These three emerging streams of research in vestibular science are—at least in part—associated with different neuronal core mechanisms. Spatial transformations draw on parietal areas, body representation is associated with somatosensory areas, and affective processes involve insular and cingulate cortices, all of which receive vestibular input. Even though a wide range of different vestibular cortical projection areas has been ascertained, their functionality still is scarcely understood.