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1.
J Neurosci Res ; 102(3): e25248, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37815024

ABSTRACT

A crucial skill, especially in rapidly changing environments, is to be able to learn efficiently from prior rewards or losses and apply this acquired knowledge in upcoming situations. Often, we must weigh the risks of different options and decide whether an option is worth the risk or whether we should choose a safer option. The ventromedial prefrontal cortex (vmPFC) is suggested as a major hub for basic but also higher-order reward processing. Dysfunction in this region has been linked to cognitive risk factors for depression and behavioral addictions, including reduced optimism and feedback learning. Here, we test whether modulations of vmPFC excitability via noninvasive transcranial direct current stimulation (tDCS) can alter reward anticipation and reward processing. In a financial gambling task, participants chose between a higher and a lower monetary risk option and eventually received feedback whether they won or lost. Simultaneously feedback on the unchosen option was presented as well. Behavioral and magnetoencephalographic correlates of reward processing were evaluated in direct succession of either excitatory or inhibitory tDCS of the vmPFC. We were able to show modulated reward approach behavior (expectancy of greater reward magnitudes) as well as altered reevaluation of received feedback by vmPFC tDCS as indicated by modified choice behavior following the feedback. Thereby, tDCS not only influenced early, rather basic reward processing, but it also modulated higher-order comparative feedback evaluation of gains and losses relative to alternative outcomes. The neural results underline this idea, as stimulation-driven modulations of the basic reward-related effect occurred at rather early time intervals and were followed by stimulation effects related to comparative reward processing. Importantly, behavioral ratings were correlated with neural activity in left frontal areas. Our results imply a dual function of the vmPFC consisting of approaching reward (as indicated by more risky choices) and elaborately evaluating outcomes. In addition, our data suggest that vmPFC activity is associated with adaptive decision-making in the future via modulated behavioral adaptation or reinforcement learning.


Subject(s)
Transcranial Direct Current Stimulation , Humans , Transcranial Direct Current Stimulation/methods , Reward , Prefrontal Cortex/physiology , Magnetoencephalography , Reinforcement, Psychology
2.
Psychophysiology ; 61(11): e14646, 2024 Nov.
Article in English | MEDLINE | ID: mdl-38963073

ABSTRACT

Flexible use of emotion regulation (ER) strategies is central to mental health. To advance our understanding of what drives adaptive strategy-switching decisions, in this preregistered study, we used event-related potentials (late positive potential, LPP and stimulus preceding negativity, SPN) and facial electromyography (EMG corrugator activity) to test the antecedents and consequences of switching to an alternative ER strategy. Participants (N = 63, Mage = 24.8 years, all female) passively watched and then implemented an instructed ER strategy (reappraisal or distraction) in response to high-intensity negative pictures that were either easy or difficult to reinterpret (high or low reappraisal affordance, respectively). Next, they decided to "switch from" or "maintain" the instructed strategy and subsequently implemented the chosen strategy. Reappraisal affordance manipulations successfully induced switching. Regarding antecedents, switching was predicted by the reduced ER efficacy of the current strategy (corrugator, but not LPP). Switching to distraction was additionally predicted by increased responses to the stimulus during passive viewing (corrugator and LPP) and increased anticipatory effort in implementing reappraisal (SPN). Concerning consequences, switching to distraction improved, whereas switching to reappraisal impaired post-choice ER effects (LPP). However, starting with reappraisal was overall more effective than starting with distraction, irrespective of the subsequent decision (corrugator). Our results suggest that switching between ER strategies occurs in accordance with situational demands (stimulus affordances) and is predicted by reduced peripheral physiological ER efficacy. However, only switching to distraction leads to improved regulatory effects. These insights provide neurocognitively grounded starting points for developing interventions targeting ER flexibility.


Subject(s)
Electroencephalography , Electromyography , Emotional Regulation , Evoked Potentials , Humans , Female , Young Adult , Adult , Emotional Regulation/physiology , Evoked Potentials/physiology , Facial Muscles/physiology , Attention/physiology , Male
3.
Laterality ; 29(3): 223-245, 2024 May.
Article in English | MEDLINE | ID: mdl-38507594

ABSTRACT

The study looked into the hemispheres' involvement in emotional word encoding. It combined brain activity measures (ERPs) with behavioural data during the affective categorization task in the divided visual field presentation paradigm. Forty healthy right-handed student volunteers took part in the study, in which they viewed and evaluated 33 positive and 33 negative emotional adjectives presented to either the left or right visual field. We observed a marginally significant effect on the earlier time window (220-250 ms, the P2 component) with higher mean amplitudes evoked to the words presented to the right hemisphere, and then a strong effect on the 340-400 ms (the P3) with a reversed pattern (higher amplitudes for words presented to the left hemisphere). The latter effect was also visible in the error rates and RTs, with better overall performance for adjectives presented to the left hemisphere. There was also an effect on behavioural data of positive words only (higher error rates, shorter RTs). Thus, the study showed a particular "progression" pattern of hemispheric engagement: dependence of the initial stages of affective lexico-semantic processing on the right hemisphere, replaced by the left-hemispheric dominance for content evaluation and response programming stages.


Subject(s)
Electroencephalography , Functional Laterality , Visual Fields , Humans , Female , Male , Visual Fields/physiology , Young Adult , Functional Laterality/physiology , Adult , Reaction Time/physiology , Evoked Potentials/physiology , Brain/physiology , Photic Stimulation/methods , Emotions/physiology , Semantics
4.
J Cogn Neurosci ; 35(10): 1656-1669, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37584600

ABSTRACT

Self-control is a core aspect of adaptive human behavior. It allows the attainment of personal goals by regulating unwanted thoughts, emotions, and behavior. Previous research highlighted the crucial role of cognitive control for explicitly pursued self-control and explicit emotion regulation strategies (such as cognitive reappraisal or attentional distraction). The present study investigated whether similar neural mechanisms would be involved in an implicit self-control task that acted as a covert emotion regulation strategy. Thirty-six female participants unscrambled sentences of either neutral (no-regulation condition) or neutral and self-control-related content (regulation condition) before passively viewing negative and neutral pictures. Compared with the no-regulation condition, implicit induction of self-control reduced the amplitude of the late positive potential to negative pictures, indicating successful emotion downregulation. Crucially, implicit self-control enhanced connectivity within the two cognitive control brain networks in the theta frequency band. Specifically, for the frontoparietal network, increased connectivity from the dorsolateral PFC to the intraparietal cortex was observed. For the cingulo-opercular network, increased connectivity from dorsal anterior cingulate cortex to the left anterior insula/frontal operculum and from the right anterior insula/frontal operculum to the dorsal anterior cingulate cortex was observed. These effects were accompanied by a decrease in prestimulus alpha power in the right primary visual cortex, suggesting adjustment of attentional and perceptual processes in preparation for the upcoming affective stimulation. Together, our results indicate that self-control enhances cognitive control that is necessary for setting, maintaining, and monitoring the achievement of self-control behavior, as well as regulation of attentional and emotional processes.


Subject(s)
Brain , Emotions , Humans , Female , Brain/diagnostic imaging , Emotions/physiology , Cerebral Cortex , Brain Mapping/methods , Magnetic Resonance Imaging/methods , Cognition
5.
Brain Topogr ; 34(4): 537-554, 2021 07.
Article in English | MEDLINE | ID: mdl-33973137

ABSTRACT

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.


Subject(s)
Metaphor , Schizophrenia , Brain/diagnostic imaging , Brain Mapping , Comprehension , Electroencephalography , Humans , Magnetic Resonance Imaging , Schizophrenia/diagnostic imaging
6.
Cogn Affect Behav Neurosci ; 20(2): 276-293, 2020 04.
Article in English | MEDLINE | ID: mdl-31950439

ABSTRACT

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.


Subject(s)
Brain Mapping , Brain/physiopathology , Cognition/physiology , Emotions/physiology , Pain/physiopathology , Adult , Brain/physiology , Brain Mapping/methods , Female , Humans , Young Adult
7.
Brain Cogn ; 143: 105595, 2020 08.
Article in English | MEDLINE | ID: mdl-32544794

ABSTRACT

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.


Subject(s)
Emotions , Visual Perception , Brain , Electroencephalography , Exercise , Female , Humans , Male , Photic Stimulation
8.
Cogn Affect Behav Neurosci ; 16(6): 1099-1113, 2016 12.
Article in English | MEDLINE | ID: mdl-27572661

ABSTRACT

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.


Subject(s)
Cerebral Cortex/physiopathology , Depression/physiopathology , Emotions/physiology , Thinking/physiology , Cluster Analysis , Depression/psychology , Electroencephalography , Emotional Intelligence/physiology , Executive Function/physiology , Female , Humans , Male , Neural Pathways/physiopathology , Psychiatric Status Rating Scales , Signal Processing, Computer-Assisted , Surveys and Questionnaires
9.
Brain Topogr ; 29(2): 253-61, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26440605

ABSTRACT

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.


Subject(s)
Attention/physiology , Brain Mapping , Emotions/physiology , Models, Neurological , Prefrontal Cortex/physiology , Adolescent , Adult , Brain Waves/physiology , Electroencephalography , Female , Humans , Male , Multivariate Analysis , Photic Stimulation , Young Adult
10.
Exp Brain Res ; 233(3): 723-33, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25424865

ABSTRACT

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.


Subject(s)
Affect/physiology , Brain/physiology , Emotions/physiology , Models, Psychological , Electroencephalography , Female , Humans , Male , Young Adult
11.
Brain Cogn ; 90: 109-15, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25014411

ABSTRACT

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.


Subject(s)
Affect/physiology , Cerebral Cortex/physiology , Nerve Net/physiology , Adult , Brain Waves , Data Interpretation, Statistical , Electroencephalography , Female , Frontal Lobe/physiology , Humans , Imagination , Parietal Lobe/physiology , Temporal Lobe/physiology , Young Adult
12.
Sci Rep ; 14(1): 21193, 2024 09 11.
Article in English | MEDLINE | ID: mdl-39261550

ABSTRACT

Higher cardiorespiratory fitness has been associated with improved cognitive control in preadolescent children, with various studies highlighting related brain health benefits. This cross-sectional study aimed to provide novel insights into the fitness-cognition relationship by investigating task-related changes in effective connectivity within two brain networks involved in cognitive control: the cingulo-opercular and fronto-parietal networks. Twenty-four higher-fit and twenty-four lower-fit preadolescent children completed a modified flanker task that modulated inhibitory control demand while their EEG and task performance were concurrently recorded. Effective connectivity for correct trials in the theta band was estimated using directed transfer function. The results indicate that children with higher fitness levels demonstrated greater connectivity in specific directions within the cingulo-opercular network (average effect size, d = 0.72). Brain-behavior correlations demonstrated a positive association between the majority of these connections and general task accuracy, which was also higher in higher fit children (average correlation coefficient, ρ = 0.34). The findings further support a positive relationship between fitness and cognitive performance in children. EEG findings offer novel insights into the potential brain mechanisms underlying the fitness-cognition relationship. The study suggests that increased task-related connectivity within the cingulo-opercular network may mediate the cognitive benefits associated with higher fitness levels in preadolescent children.


Subject(s)
Cardiorespiratory Fitness , Cognition , Electroencephalography , Humans , Child , Cognition/physiology , Male , Female , Cardiorespiratory Fitness/physiology , Cross-Sectional Studies , Nerve Net/physiology , Gyrus Cinguli/physiology , Brain/physiology
13.
Biol Psychol ; 186: 108743, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38195048

ABSTRACT

Reappraisal is a complex emotional control strategy based on cognitive change. To complete the reappraisal task, one is required to deeply elaborate on the affective stimulus to create its new interpretation. The involvement of the prefrontal cortex in this process was examined in the study, where inhibition of the left or right dorsolateral area was carried out using transcranial magnetic stimulation. In a between-subject design, we used an alternative control condition for the reappraisal task. It was intended to better account for overall task activity compared to typical passive conditions. Late positive potential was affected after inhibition of the prefrontal area, suggesting hindered emotional control. This effect was specific to the reappraisal task, which possibly reflects the disturbance of attention allocation to emotional stimuli. We could also observe an increased transfer of information from the visual area during the control task that was based on the elaboration of emotional stimuli but did not involve cognitive change. Our results support the additive impact of several factors on the overall efficiency of emotional control.


Subject(s)
Emotions , Prefrontal Cortex , Humans , Emotions/physiology , Prefrontal Cortex/physiology , Attention/physiology , Transcranial Magnetic Stimulation/methods
14.
Med Sci Monit ; 19: 283-8, 2013 Apr 19.
Article in English | MEDLINE | ID: mdl-23598598

ABSTRACT

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 AND 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.


Subject(s)
Cognition/physiology , Liver Cirrhosis/complications , Liver Cirrhosis/physiopathology , Memory Disorders/complications , Memory , Adult , Demography , Female , Humans , Male , Memory Disorders/physiopathology , Neuropsychological Tests , Psychometrics
15.
Psychophysiology ; 60(1): e14137, 2023 01.
Article in English | MEDLINE | ID: mdl-35790005

ABSTRACT

Depression has been characterized by lowered mood and unfavorable changes in neural emotional reactivity (altered brain responses to emotional stimuli). Physical exercise is a well-established strategy to improve the mood of healthy and depressed individuals. Increasing evidence suggests that exercise might also improve emotional reactivity in healthy adults by increasing or decreasing brain responses to positive or negative stimuli, respectively. It is unknown, however, if exercise could also benefit emotional reactivity in depressed individuals. We investigated the effects of a single aerobic exercise session on mood and emotional reactivity in 24 depressed and 24 matched healthy young adults. Self-reported mood and neural reactivity to emotional pictures (indexed by the EEG late positive potential, LPP) were assessed before and after two experimental protocols: exercise (36 min of moderate-intensity exercise at 75% of maximal heart rate) and seated rest condition (36 min). In the healthy control group, exercise improved self-reported mood and neural emotional reactivity (increasing LPP to positive pictures). In the depressed group, exercise improved self-reported mood; however, it did not affect neural emotional reactivity. Additional analyses performed on both groups revealed that exercise-induced changes in emotional reactivity are associated with the severity of depressive symptoms: the effectiveness of exercise in improving emotional reactivity decreases with the severity of depressive symptoms. Overall, the study further strengthens the claim of a beneficial role of exercise on mood and emotional reactivity. It also suggests that a single aerobic exercise session might have a limited influence on neural emotional reactivity in depressed individuals.


Subject(s)
Affect , Emotions , Young Adult , Humans , Affect/physiology , Emotions/physiology , Exercise , Brain , Self Report
16.
Psychophysiology ; 60(9): e14316, 2023 09.
Article in English | MEDLINE | ID: mdl-37162260

ABSTRACT

Evolutionary threats (ETs), such as predatory animals and heights, elicit stronger fear responses and are more often the subject of specific phobias, as compared to modern threats (MTs, such as guns and motorcycles). Since processing of ET depends on lower-order, phylogenetically conserved neural fear circuits, it may be less susceptible to higher-order (vs. simpler) cognitive emotion regulation. Given the relevance for treatment of specific phobias, we tested this hypothesis in an ERP study. Sixty-one female participants passively watched high- and low-threat pictures of evolutionary (snakes, lizards) and modern (guns, water-guns) origin, and downregulated responses to the high-threat pictures (snakes and guns) using either cognitive reappraisal or a simpler cognitive distraction strategy. ET elicited stronger early (EPN) and sustained (LPP) attention processing compared to MT. Both strategies successfully downregulated subjective and LPP (but not EPN) responses compared to passive watching. Although reappraisal was more effective subjectively, distraction downregulated the LPP earlier and stronger than reappraisal, irrespective of the threat type. These findings provide novel evidence that neural responses to physical threat might be less susceptible to cognitive emotion regulation via higher-order (reappraisal) versus simpler (distraction) strategies, irrespective of the evolutionary or modern relevance of threat. Combining both strategies could be beneficial for the emotion regulation-enhancing interventions for specific phobias. Distraction could be used during initial exposure, to reduce immediate emotion responding and help endure the contact with the feared stimulus, whereas reappraisal could be used subsequently, when emotions are less intense, to change maladaptive thoughts about the stimulus for future encounters.


Subject(s)
Electroencephalography , Evoked Potentials , Animals , Female , Down-Regulation , Evoked Potentials/physiology , Emotions/physiology , Fear , Cognition/physiology
17.
Front Neurosci ; 17: 1219029, 2023.
Article in English | MEDLINE | ID: mdl-37650099

ABSTRACT

Introduction: Studies suggest an involvement of the ventromedial prefrontal cortex (vmPFC) in reward prediction and processing, with reward-based learning relying on neural activity in response to unpredicted rewards or non-rewards (reward prediction error, RPE). Here, we investigated the causal role of the vmPFC in reward prediction, processing, and RPE signaling by transiently modulating vmPFC excitability using transcranial Direct Current Stimulation (tDCS). Methods: Participants received excitatory or inhibitory tDCS of the vmPFC before completing a gambling task, in which cues signaled varying reward probabilities and symbols provided feedback on monetary gain or loss. We collected self-reported and evaluative data on reward prediction and processing. In addition, cue-locked and feedback-locked neural activity via magnetoencephalography (MEG) and pupil diameter using eye-tracking were recorded. Results: Regarding reward prediction (cue-locked analysis), vmPFC excitation (versus inhibition) resulted in increased prefrontal activation preceding loss predictions, increased pupil dilations, and tentatively more optimistic reward predictions. Regarding reward processing (feedback-locked analysis), vmPFC excitation (versus inhibition) resulted in increased pleasantness, increased vmPFC activation, especially for unpredicted gains (i.e., gain RPEs), decreased perseveration in choice behavior after negative feedback, and increased pupil dilations. Discussion: Our results support the pivotal role of the vmPFC in reward prediction and processing. Furthermore, they suggest that transient vmPFC excitation via tDCS induces a positive bias into the reward system that leads to enhanced anticipation and appraisal of positive outcomes and improves reward-based learning, as indicated by greater behavioral flexibility after losses and unpredicted outcomes, which can be seen as an improved reaction to the received feedback.

18.
Sci Rep ; 13(1): 17984, 2023 10 20.
Article in English | MEDLINE | ID: mdl-37863877

ABSTRACT

Humans are subject to a variety of cognitive biases, such as the framing-effect or the gambler's fallacy, that lead to decisions unfitting of a purely rational agent. Previous studies have shown that the ventromedial prefrontal cortex (vmPFC) plays a key role in making rational decisions and that stronger vmPFC activity is associated with attenuated cognitive biases. Accordingly, dysfunctions of the vmPFC are associated with impulsive decisions and pathological gambling. By applying a gambling paradigm in a between-subjects design with 33 healthy adults, we demonstrate that vmPFC excitation via transcranial direct current stimulation (tDCS) reduces the framing-effect and the gambler's fallacy compared to sham stimulation. Corresponding magnetoencephalographic data suggest improved inhibition of maladaptive options after excitatory vmPFC-tDCS. Our analyses suggest that the underlying mechanism might be improved reinforcement learning, as effects only emerge over time. These findings encourage further investigations of whether excitatory vmPFC-tDCS has clinical utility in treating pathological gambling or other behavioral addictions.


Subject(s)
Gambling , Transcranial Direct Current Stimulation , Adult , Humans , Gambling/pathology , Feedback , Prefrontal Cortex/physiology , Bias , Cognition
19.
Neurol Neurochir Pol ; 46(5): 436-42, 2012.
Article in English | MEDLINE | ID: mdl-23161187

ABSTRACT

BACKGROUND AND PURPOSE: The results of a few studies suggest that magnetic resonance spectroscopy of the brain could allow detection of minimal hepatic encephalopathy. The goal of this study was to assess the ability of magnetic resonance spectroscopy to differentiate between cirrhotic patients with and without minimal hepatic encephalopathy. MATERIAL AND METHODS: Localized magnetic resonance spectroscopy was performed in the basal ganglia, occipital gray matter and frontal white matter in 46 patients with liver cirrhosis without overt encephalopathy and in 45 controls. Neurological and neuropsychological examination was performed in each participant. RESULTS: The patients with liver cirrhosis had a decreased ratio of myoinositol to creatine in occipital gray matter and frontal white matter (mean: 0.17 ± 0.05 vs. 0.20 ± 0.04, p = 0.01 and 0.15 ± 0.05 vs. 0.19 ± 0.04, p < 0.01, respectively) and a decreased ratio of choline to creatine in occipital gray matter (mean: 0.32 ± 0.07 vs. 0.36 ± 0.08, p = 0.03). Minimal hepatic encephalopathy was diagnosed in 7 patients. Metabolite ratios did not differ significantly between patients with and without minimal hepatic encephalopathy. Metabolite ratios did not differ significantly between patients with Child-Pugh A and those with Child-Pugh B. CONCLUSIONS: Magnetic resonance spectroscopy does not allow accurate diagnosis of minimal hepatic encephalopathy. A similar profile of metabolites in the brain is observed in cirrhotic patients without cognitive impairment.


Subject(s)
Creatine/metabolism , Hepatic Encephalopathy/diagnosis , Hepatic Encephalopathy/metabolism , Inositol/metabolism , Magnetic Resonance Spectroscopy/methods , Adult , Basal Ganglia/metabolism , Basal Ganglia/pathology , Cerebral Cortex/pathology , Female , Frontal Lobe/metabolism , Frontal Lobe/pathology , Hepatic Encephalopathy/etiology , Humans , Liver Cirrhosis/complications , Liver Cirrhosis/metabolism , Male , Occipital Lobe/metabolism , Occipital Lobe/pathology
20.
Biol Psychol ; 171: 108327, 2022 05.
Article in English | MEDLINE | ID: mdl-35405285

ABSTRACT

The present experiments investigated the impact of working memory (WM) load on emotion regulation (ER) efficacy using reappraisal (Experiment 1, n = 30) and distraction (Experiment 2, n = 30). Considering that WM is necessary for storage, elaboration, and manipulation of information and that reappraisal acts by storing, elaborating, and manipulating the stimulus meaning, we hypothesized that high (versus low) WM-load would reduce reappraisal efficacy. By contrast, given that distraction acts by blocking elaborated processing of the stimulus meaning, we expected that high WM-load would enhance distraction efficacy. To test these predictions, we employed a dual-task paradigm in which a low- or high WM-load task was combined with an ER (reappraisal or distraction) task. We measured the Late Positive Potential (LPP)-an electrocortical marker of sustained motivated attention, and a well-established index of emotional arousal-in response to negative pictures. Results confirmed that although reappraisal successfully reduced the LPP amplitude in the down- compared to up-regulation condition in low WM-load trials, high WM-load eliminated this difference, suggesting the disrupting influence of high WM-load on ER for reappraisal (Experiment 1). By contrast, although distraction failed to modulate the LPP amplitude in low WM-load trials, the difference between down- and no-regulation conditions was significant when distraction was combined with high WM-load, suggesting the facilitatory influence of high WM-load on ER for distraction (Experiment 2). Our findings show that the effect of WM-load on ER is strategy-dependent, and that the availability of WM resources is an important situational moderator of ER efficacy in healthy young adults.


Subject(s)
Electroencephalography , Memory, Short-Term , Cognition/physiology , Electroencephalography/methods , Emotions/physiology , Evoked Potentials/physiology , Humans , Memory, Short-Term/physiology , Young Adult
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