Miroslaw Wyczesany

Individual differences in epistemic motivation and brain conflict monitoring activity.

It is well documented that motivation toward closure (NFC), defined as a desire for a quick and unambiguous answer to a question and an aversion to uncertainty, is linked to more structured, rigid, and persistent cognitive styles. However, the neurocognitive correlates of NFC have never been tested. Thus, using event-related potentials, we examined the hypothesis that NFC is associated with the neurocognitive process for detecting discrepancies between response tendencies and higher level intentions. We found that greater NFC is associated with lower conflict-related anterior cingulate activity, suggesting lower sensitivity to cues for altering a habitual response pattern and lower sensitivity to committing errors. This study provides evidence that high NFC acts as a bulwark against anxiety-producing uncertainty and minimizes the experience of error.

Interactions Between the Prefrontal Cortex and Attentional Systems During Volitional Affective Regulation: An Effective Connectivity Reappraisal Study

Reappraisal is an emotion regulation strategy used to change reactions to emotion-related stimuli by reinterpreting their meaning. During down-regulation of negative emotions, wide areas of the prefrontal cortex (PFC) inhibit emotion-related brain areas such as the amygdala. Little is known, however, about how this control activity influences the earliest stages of affective responses by modulating perceptual and attentional areas. The aim of this study is to identify the connectivity patterns between the PFC and the core regions of two well-known attentional networks: the dorsal attentional network (which controls attention volitionally) and the ventral attentional network (which controls attention spontaneously) during reappraisal. We used a novel method to study emotional control processes: the directed transfer function, an autoregressive effective connectivity method based on Granger causality. It was applied to EEG recordings to quantify the direction and intensity of information flow during passively watching (control condition) or reappraising (experimental condition) negative film clips. Reappraisal was mostly associated with increased top-down influences from the right dorsolateral PFC over attentional and perceptual areas, reaching areas including dorsal attentional regions. The left dorsolateral PFC was associated with the activation of the ventral attentional network. Passively watching clips (control condition) resulted in increased flow from attentional areas to the left dorsolateral PFC, what is interpreted as a monitoring process. Thus, reappraisal seems to be related to both volitional and automatic control of attention, triggered by the right and left dorsolateral PFC respectively.

Cortical functional connectivity is associated with the valence of affective states

The study investigates the relationships between the valence of affective states and the cortical patterns of functional connectivity. The information flow rate and direction were estimated by means of Directed Transfer Function (DTF), a multivariate method based on Granger causality. It was calculated on EEG activity recorded during mental imagery tasks. As a result, three regions were revealed as main network hubs, where the information outflow changed specifically with valence: the anterior orbitofrontal cortex, and the right posterior and right temporal area. The role of these structures in synchronizing the cortical affective network as well as in mediating different aspects of emotional state is discussed.

Covariation of EEG synchronization and emotional state as modified by anxiolytics

Summary: The relationships between subjective estimation of emotional state and synchronization patterns in cortical emotional systems were investigated. The emotional state varied between groups using diazepam, buspirone, and placebo. The University of Wales Institute of Science and Technology Mood Adjective Checklist was used for the assessment of emotional state in the drug condition, yielding three estimates of emotional state: Energetic Arousal, Tension Arousal, and Hedonic Tone. These measures were correlated with the Synchronization Likelihood index of the resting EEG. Increased affective valence and arousal were related to an increased level of synchronization between frontal and right temporoparietal emotional areas. Two identified centers of synchronization, localized in the temporal and centroparietal regions, appeared to be functionally distinct. Stable relationships between subjective emotional state measures and cortical EEG synchronization patterns were confirmed, especially for the valence and energetic arousal estimation. A higher synchronization is associated with increased emotional valence and arousal, and this can thus be seen as a neural correlate of emotional experiences.

Electrocortical indices of attention correlate with the need for closure.

Need for closure (NFC), defined as a desire for a quick and unambiguous answer to a question and an aversion to uncertainty, usually leads to a more structured, persistent, and rigid cognitive style. We suggested that this cognitive characteristic could be related to differences in a simple sensory gating control mechanism as reflected in event-related potentials (N1 component). We expected that the higher an individual’s NFC, the more attention he/she would allocate to the selected stimuli or the feature of the stimuli, which is manifested in an increased N1 component. We tested this assumption in two experiments where NFC was measured by a scale and event-related potentials were recorded during the Stroop task and the Visual Distractor task. In line with the hypotheses, we found that NFC was associated with amplified processing of stimuli at an early sensory stage, which was evidenced in an increased N1 component. We suggested that this early sensory gating mechanism protects high NFC individuals against anxiety-producing uncertainty.

Effective connectivity during visual processing is affected by emotional state

The limitations of our cognitive resources necessitate the selection of relevant information from the incoming visual stream. This selection and prioritizing of stimuli allows the organism to adapt to the current conditions. However, the characteristics of this process vary with time and depend on numerous external and internal factors. The present study was aimed at determining how the emotional state affects effective connectivity between visual, attentional and control brain areas during the perception of affective visual stimuli. The Directed Transfer Function was applied on a 32-electrode EEG recording to quantify the direction and intensity of the information flow during two sessions: positive and negative. These data were correlated with a self-report of the emotional state. We demonstrated that the current mood, as measured by self-report, is a factor which affects the patterns of effective cortical connectivity. An increase in prefrontal top-down control over the visual and attentional areas was revealed in a state of tension. It was accompanied by increased outflow within and from the areas recognized as the ventral attentional network. By contrast, a positive emotional state was associated with heightened flow from the parietal to the occipital area. The functional significance of the revealed effects is discussed.

The influence of context on the processing of emotional and neutral adjectives – An ERP study

The study investigated brain responses to emotional and neutral adjectives within contexts of varying emotional valence. Participants were randomly assigned to 3 context groups where they viewed random sequences of emotional and neutral adjectives intermixed with: emotional pictures (emotional context), neutral pictures (neutral context) and blank screens (zero context). Within the emotional context group the P3 potential was more pronounced in response to positive than either negative or neutral adjectives, and positive picture context impacted positive and negative adjectives differently. In the neutral context group the P2 and P3 potentials were greater in response to the positive adjectives as compared to the neutral ones. There was also a greater negativity of the N400 potential in response to the neutral adjectives. Within the zero context group only the N400 effect was visible. The seeming preference for positive words can be explained in terms of the specific positivity offset phenomenon.

Cognitive functions in patients with liver cirrhosis: A tendency to commit more memory errors

Background Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE). For diagnostic purposes, 2 alternative batteries of psychometric screening tests are recommended. They differ from each other in terms of the cognitive domains assessed. The research was designed to provide a profile of cognitive functioning in patients with liver cirrhosis, using an assessment that covers a wider range of cognitive functions than the usual screening battery. Material/Methods We examined 138 persons, including 88 with liver cirrhosis and 50 healthy volunteers. The Mini Mental State Examination (MMSE) was used for screening and excluding advanced cognitive impairment. Then, to assess cognitive functions in more detail, the following tests were used: Auditory Verbal Learning Test (AVLT), Letter and Semantic Fluency Tests (LF and SF), Trail Making Test (TMT A&B), Digit Symbol Test (DST), Block Design Test (BDT), and Mental Rotation Test (MRT). The MRT task has not been used in MHE diagnosis so far. Finally, 57 patients and 48 controls took part in the entire study. Results Patients with liver cirrhosis commit significantly more errors of intrusions in the AVLT during the delayed free recall trial. Results significantly deviating from the norm in at least 2 tests were found only in 7 cirrhosis patients. Conclusions The results do not provide any specific profile of cognitive disturbances in MHE, but suggest that cirrhosis patients have a tendency to commit more memory errors, probably due to subtle impairments of executive function.

Neural circuit of verbal humor comprehension in schizophrenia - an fMRI study

Individuals with schizophrenia exhibit problems with understanding the figurative meaning of language. This study evaluates neural correlates of diminished humor comprehension observed in schizophrenia. The study included chronic schizophrenia (SCH) outpatients (n = 20), and sex, age and education level matched healthy controls (n = 20). The fMRI punchline based humor comprehension task consisted of 60 stories of which 20 had funny, 20 nonsensical and 20 neutral (not funny) punchlines. After the punchlines were presented, the participants were asked to indicate whether the story was comprehensible and how funny it was. Three contrasts were analyzed in both groups reflecting stages of humor processing: abstract vs neutral stories - incongruity detection; funny vs abstract - incongruity resolution and elaboration; and funny vs neutral – complete humor processing. Additionally, parametric modulation analysis was performed using both subjective ratings separately. Between-group comparisons revealed that the SCH subjects had attenuated activation in the right posterior superior temporal gyrus (BA 41) in case of irresolvable incongruity processing of nonsensical puns; in the left dorsomedial middle and superior frontal gyri (BA 8/9) in case of incongruity resolution and elaboration processing of funny puns; and in the interhemispheric dorsal anterior cingulate cortex (BA 24) in case of complete processing of funny puns. Additionally, during comprehensibility ratings the SCH group showed a suppressed activity in the left dorsomedial middle and superior frontal gyri (BA 8/9) and revealed weaker activation during funniness ratings in the left dorsal anterior cingulate cortex (BA 24). Interestingly, these differences in the SCH group were accompanied behaviorally by a protraction of time in both types of rating responses and by indicating funny punchlines less comprehensible. Summarizing, our results indicate neural substrates of humor comprehension processing impairments in schizophrenia, which is accompanied by fronto-temporal hypoactivation.

Depressive rumination and the emotional control circuit: An EEG localization and effective connectivity study.

Ruminations are repetitive thoughts associated with symptoms, causes, and consequences of one’s negative feelings. The objective of this study was to explore the neuronal basis of depressive rumination in a non-clinical population within the context of emotional control. Participants scoring high or low on the tendency to ruminate scale took part in the EEG experiment. Their EEG data were collected during a state of induced depressive ruminations and compared with positive and neutral conditions. We hypothesized that both groups would differ according to the level of activation and effective connectivity among the structures involved in the emotional control circuit. Clustering of independent components, together with effective connectivity (Directed Transfer Function), was performed using the EEG signal. The main findings involved decreased activation of the left dorsolateral prefrontal cortex (DLPFC) and increased activation of the left temporal lobe structures in the highly ruminating group. The latter result was most pronounced during the ruminative condition. Decreased information from the left DLPFC to the left temporal lobe structures was also found, leading to the conclusion that hypoactivation of the left DLPFC and its inability to modulate the activation of the left temporal lobe structures is crucial for the ruminative tendencies.