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Figurative language processing (e.g. metaphors) is commonly impaired in schizophrenia. In the present study, we investigated the neural activity and propagation of information within neural circuits related to the figurative speech, as a neural substrate of impaired conventional metaphor processing in schizophrenia. The study included 30 schizophrenia outpatients and 30 healthy controls, all of whom were assessed with a functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG) punchline-based metaphor comprehension task including literal (neutral), figurative (metaphorical) and nonsense (absurd) endings. The blood oxygenation level-dependent signal was recorded with 3T MRI scanner and direction and strength of cortical information flow in the time course of task processing was estimated with a 64-channel EEG input for directed transfer function. The presented results revealed that the behavioral manifestation of impaired figurative language in schizophrenia is related to the hypofunction in the bilateral fronto-temporo-parietal brain regions (fMRI) and various differences in effective connectivity in the fronto-temporo-parietal circuit (EEG). Schizophrenia outpatients showed an abnormal pattern of connectivity during metaphor processing which was related to bilateral (but more pronounced at the left hemisphere) hypoactivation of the brain. Moreover, we found reversed lateralization patterns, i.e. a rightward-shifted pattern during metaphor processing in schizophrenia compared to the control group. In conclusion, the presented findings revealed that the impairment of the conventional metaphor processing in schizophrenia is related to the bilateral brain hypofunction, which supports the evidence on reversed lateralization of the language neural network and the existence of compensatory recruitment of alternative neural circuits in schizophrenia. Supplementary Information The online version contains supplementary material available at 10.1007/s10548-021-00849-x.

There seems to be a general consensus among researchers that acute aerobic exercise (exercise hereafter) improves mood, but the neural mechanisms which drive these effects are far from being clear. The current study investigated the cortical connectivity patterns that underlie changes in mood after exercise. Twenty male adults underwent three different experimental protocols that were carefully controlled in terms of underlying metabolism and were administered in a randomized order: moderate-intensity continuous exercise, high-intensity interval exercise, and seated rest condition. Before and after each experimental protocol, we collected data on the participants' mood using the UMACL questionnaire and recorded their resting-state EEG. We focused on the effective connectivity patterns exerted by the dorso-lateral prefrontal cortex (dlPFC) over the temporal region (TMP), as these are important cortical structures involved in shaping mood. The cortical connectivity patterns in the resting-state EEG were evaluated using the directed transfer function (DTF), which is an autoregressive effective connectivity method. The results showed that both moderate-intensity exercise and high-intensity interval exercise improved participants' self-reported mood. Crucially, this improvement was accompanied by stronger influences of dlPFC over TMP. The observed changes in the effective connectivity patterns between dlPFC and TMP might help to better understand the effects of exercise on mood.

This study was designed to investigate the neural mechanism of cognitive modulation of pain via a reappraisal strategy with high temporal resolution. The EEG signal was recorded from 29 participants who were instructed to down-regulate, up-regulate, or maintain their pain experience. The L2 minimum norm source reconstruction method was used to localize areas in which a significant effect of the instruction was present. Down-regulating pain by reappraisal exerted a robust effect on pain processing from as early as ~100 ms that diminished the activity of limbic brain regions: the anterior cingulate cortex, right orbitofrontal cortex, left anterior temporal region, and left insula. However, compared with the no-regulation condition, the neural activity was similarly attenuated in the up- and down-regulation conditions. We suggest that this effect could be ascribed to the cognitive load that was associated with the execution of a cognitively demanding reappraisal task that could have produced a general attenuation of pain-related areas regardless of the aim of the reappraisal task (i.e., up- or down-regulation attempts). These findings indicate that reappraisal effects reflect the joint influence of both reappraisal-specific (cognitive change) and unspecific (cognitive demand) factors, thus pointing to the importance of cautiously selected control conditions that allow the modulating impact of both processes to be distinguished.

Reappraisal is an emotion regulation strategy which involves changing the interpretation of emotional stimuli. It decreases measures of negative affect together with markers of emotional processing, including late positive potential (LPP). Affective responses can also be attenuated by various cognitive tasks. As reappraisal tasks require cognitive effort to elaborate emotional stimuli, it is possible that the observed reduction of the LPP amplitude during reinterpretation is, at least partly, caused by an unspecific cognitive activity. The aim of the study was to examine, whether mental activity other than cognitive change carried out directly on affective stimuli can be a factor that significantly modifies the intensity of the emotional responses. Three groups took part in an experiment with standardized emotional pictures: a reappraisal group (trained in reinterpretation), a retro group (trained in cognitive elaboration of emotional stimuli other than cognitive change), and a control group (passive viewing). The early LPP potential showed a main effect of group with the highest amplitude in the control group and the lowest amplitude in the reappraisal group. The retro group revealed no significant differences comparing with the other two groups. The late LPP was indistinguishable in the reappraisal and retro groups, which showed an equal decrease in its amplitude compared to the control group in the case of negative stimuli. Conversely, behavioral ratings collected in a separate group of subjects showed a decrease in negative feelings in the reappraisal group only. We conclude that the LPP component during reappraisal is under additive influence from the cognitive change itself and from unspecific cognitive activity; however, both of them differ in regard to their temporal characteristics.

Although acute aerobic exercise benefits different aspects of emotional functioning, it is unclear how exercise influences the processing of emotional stimuli and which brain mechanisms support this relationship. We assessed the influence of acute aerobic exercise on valence biases (preferential processing of negative/positive pictures) by performing source reconstructions of participants’ brain activity after they viewed emotional scenes. Twenty-four healthy participants (12 women) were tested in a randomized and counterbalanced design that consisted of three experimental protocols, each lasting 30 min: low-intensity exercise (Low-Int); moderate-intensity exercise (Mod-Int); and a seated rest condition (REST). After each of the protocols, participants viewed negative and positive pictures, during which event-related magnetic fields were recorded. Analyses revealed that exercise strongly impacted the valence processing of emotional scenes within a widely distributed left hemispheric spatio-temporal cluster between 190 and 310 ms after picture onset. Brain activity in this cluster showed that a negativity bias at REST (negative > positive picture processing) diminished after the Low-Int condition (positive = negative) and even reversed to a positivity bias after the Mod-Int condition (positive > negative). Thus, acute aerobic exercise of low and moderate intensities induces a positivity bias which is reflected in early, automatic processes.

Limited attention capacity results that not all the stimuli present in the visual field are equally processed. While processing of salient stimuli is automatically boosted by bottom‑up attention, processing of task‑relevant stimuli can be boosted volitionally by top‑down attention. Usually, both top‑down and bottom‑up influences are present simultaneously, which creates a competition between these two types of attention. We examined this competition using both behavioral and electrophysiological measures. Participants responded to letters superimposed on background pictures. We assumed that responding to different conditions of the letter task engages top‑down attention to different extent, whereas processing of background pictures of varying salience engages bottom‑up attention to different extent. To check how manipulation of top‑down attention influences bottom‑up processing, we measured evoked response potentials (ERPs) in response to pictures (engaging mostly bottom‑up attention) during three conditions of a letter task (different levels of top‑down engagement). Conversely, to check how manipulation of bottom‑up attention influences top‑down processing, we measured ERP responses for letters (engaging mostly top‑down attention) while manipulating the salience of background pictures (different levels of bottom‑up engagement). The correctness and reaction times in response to letters were also analyzed. As expected, most of the ERPs and behavioral measures revealed a trade‑off between both types of processing: a decrease of bottom‑up processing was associated with an increase of top‑down processing and, similarly, a decrease of top‑down processing was associated with an increase in bottom‑up processing. Results proved competition between the two types of attentions.

Limited attention capacity results that not all the stimuli present in the visual field are equally processed. While processing of salient stimuli is automatically boosted by bottom‑up attention, processing of task‑relevant stimuli can be boosted volitionally by top‑down attention. Usually, both top‑down and bottom‑up influences are present simultaneously, which creates a competition between these two types of attention. We examined this competition using both behavioral and electrophysiological measures. Participants responded to letters superimposed on background pictures. We assumed that responding to different conditions of the letter task engages top‑down attention to different extent, whereas processing of background pictures of varying salience engages bottom‑up attention to different extent. To check how manipulation of top‑down attention influences bottom‑up processing, we measured evoked response potentials (ERPs) in response to pictures (engaging mostly bottom‑up attention) during three conditions of a letter task (different levels of top‑down engagement). Conversely, to check how manipulation of bottom‑up attention influences top‑down processing, we measured ERP responses for letters (engaging mostly top‑down attention) while manipulating the salience of background pictures (different levels of bottom‑up engagement). The correctness and reaction times in response to letters were also analyzed. As expected, most of the ERPs and behavioral measures revealed a trade‑off between both types of processing: a decrease of bottom‑up processing was associated with an increase of top‑down processing and, similarly, a decrease of top‑down processing was associated with an increase in bottom‑up processing. Results proved competition between the two types of attentions.

In the study we investigated how current mood affects spontaneous perceptual processes of neutral stimuli of low‑arousal, unrelated to any specific task. Two separate but similar procedures were carried out: one using functional magnetic resonance imaging (fMRI), the other using electroencephalography based source localization. In both experiments, sessions of passive viewing of neutral pictures were preceded by either a negative or positive mood induction. In response to neutral stimuli, we observed higher activation of visual areas after positive mood induction and lower activations in medial prefrontal and right frontotemporal regions after negative mood induction. We conclude that in relatively safe laboratory conditions, after being exposed to negative emotional content, automatic processes of affective control are recruited by the prefrontal cortex. This results in attenuation of processing of incoming stimuli, as the stimuli do not carry salient information with respect to bottom‑up or top‑down processes. The observed effects may therefore represent an implicit mechanism of perceptual modulation.

The detection of cognitive conflict is thought to trigger adjustments in executive control. It has been recently shown that cognitive conflict increases processing of stimuli that are relevant to the ongoing task and that these modulations are exerted by the dorsolateral prefrontal cortex (DLPFC). However, it is still unclear whether such control influences are unspecific and might also affect the processing of task-irrelevant stimuli. The aim of the study was to examine if cognitive conflict affects processing of neutral and negative, task-irrelevant pictures. Participants responded to congruent (non-conflict) or to incongruent (conflict-eliciting) trials of a modified flanker task. Each response was followed by a presentation of a neutral or negative picture. The late positive potential (LPP) in response to picture presentation was used to assess the level of picture processing after conflict vs non-conflict trials. Connectivity between the DLPFC and attentional and perceptual areas during picture presentation was analysed to check if the DLPFC might be a source of these modulations. ERP results showed an effect of cognitive conflict only on processing of negative pictures: LPP in response to negative pictures was increased after conflict trials, whereas LPP in response to neutral pictures remained unchanged. Cortical connectivity analysis showed that conflict trials intensified information flow from the DLPFC towards attentional and perceptual regions. Results suggest that cognitive conflict increases processing of task-irrelevant stimuli; however, they must display high biological salience. Increase in cognitive control exerted by the DLPFC over attentional and perceptual regions is a probable mechanism of the effect.

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 locationist model of affect, which assumes separate brain structures devoted to particular discrete emotions, is currently being questioned as it has not received enough convincing experimental support. An alternative, constructionist approach suggests that our emotional states emerge from the interaction between brain functional networks, which are related to more general, continuous affective categories. In the study, we tested whether the three-dimensional model of affect based on valence, arousal, and dominance (VAD) can reflect brain activity in a more coherent way than the traditional locationist approach. Independent components of brain activity were derived from spontaneous EEG recordings and localized using the DIPFIT method. The correspondence between the spectral power of the revealed brain sources and a mood self-report quantified on the VAD space was analysed. Activation of four (out of nine) clusters of independent brain sources could be successfully explained by the specific combination of three VAD dimensions. The results support the constructionist theory of emotions.

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.