The Benefits of Acute Exercise for Children's Cognition are Associated with Trait Anxiety.

INTRODUCTION: Children's anxiety is associated with decreased cognitive performance. One well-established behavioral intervention to transiently improve cognitive performance in children is acute aerobic exercise (AAE). Thus far, however, it is unclear whether the benefits of AAE on cognition vary based on individual differences in children's anxiety level. Therefore, we investigated whether trait anxiety levels mediate the effects of AAE on cognitive outcomes in preadolescent children. METHODS: Ninety-five preadolescent children (9-11 years, 41 females) underwent two experimental interventions in a random, crossover, and counterbalanced design: an exercise protocol (20 minutes of walking at 65-75% of HRpeak) and a non-exercise control (seated rest). Behavioral indices of cognitive performance (accuracy, reaction times, response time variability) were assessed before and after each intervention using a modified flanker task. The effects of each intervention on cognitive performance were calculated as pre- to post-intervention differences (effect scores). These scores were first correlated with children's personal characteristics: anxiety (STAIC), sex, age, BMI, IQ, and aerobic fitness. Significant correlations guided subsequent hierarchical regression models, which specifically tested for associations between the effects scores and anxiety levels while controlling for remaining relevant covariates. RESULTS: Regression analysis revealed that anxiety was a significant predictor of the effects that AAE and rest had on cognitive performance. Specifically, higher anxiety scores were associated with greater exercise-induced cognitive benefits (increased accuracy, decreased response time variability; p's < 0.05) and greater rest-induced cognitive impairments (decreased accuracy, increased response time variability; p's < 0.01). CONCLUSIONS: These findings suggest that children reporting higher trait anxiety might experience greater cognitive benefits from a single bout of AAE.

Inhibition of the dorsolateral cortex reveals specific mechanisms behind emotional control.

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.

Acute aerobic exercise benefits allocation of neural resources related to selective attention.

A single session of aerobic exercise has been shown to potentially benefit subsequent performance in a wide range of cognitive tasks, but the underlying mechanisms are still not fully understood. In this study, we investigated the effects of exercise on selective attention, a cognitive process that involves prioritized processing of a subset of available inputs over others. Twenty-four healthy participants (12 women) underwent two experimental interventions in a random, crossover, and counterbalanced design: a vigorous-intensity exercise (60-65% HRR) and a seated rest (control) condition. Before and after each protocol, participants performed a modified selective attention task that demanded attending stimuli of different spatial frequencies. Event-related magnetic fields were concurrently recorded using magnetoencephalography. The results showed that exercise, relative to the seated rest condition, reduced neural processing of unattended stimuli and increased processing of attended stimuli. The findings suggest that changes in neural processing related to selective attention may be one of the mechanisms underlying exercise-induced improvements in cognition.

The effects of a single aerobic exercise session on mood and neural emotional reactivity in depressed and healthy young adults: A late positive potential study.

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.

Offline rTMS inhibition of the right dorsolateral prefrontal cortex impairs reappraisal efficacy.

In this study we verified the causal role of the bilateral dorsolateral prefrontal cortex (DLPFC) in emotional regulation using a strategy of reappraisal, which involves intentionally changing the meaning of an affective event to reduce its emotional impact. Healthy participants (n = 26; mean age = 25.4) underwent three sessions of inhibitory continuous theta burst stimulation (cTBS) applied on three different days over the left or right DLPFC, or the vertex. After applying the stimulation protocol participants were presented with neutral and negative pictorial stimuli that had to be either passively watched or reappraised. The efficacy of emotional control was quantified using the Late Positive Potential (LPP), the neural marker of motivated attention and elaborated stimulus processing. The results showed that reappraisal was compromised after inhibitory stimulation of the right DLPFC compared to the vertex. This impairment of affective modulation was reflected in both early (350-750 ms) and late (750-1500 ms) time windows. As no session differences during the passive watching conditions were found, the decrease in reappraisal efficacy due to non-specific changes in basic perceptual processing was considered unlikely. Instead, we suggest that inhibition of the right DLPFC primarily affects the top-down mechanism of attentional deployment. This results in disturbances of attentional processes that are necessary to thoroughly elaborate the content of affective stimuli to enable their new, less negative interpretation.

On the Role of Bilateral Brain Hypofunction and Abnormal Lateralization of Cortical Information Flow as Neural Underpinnings of Conventional Metaphor Processing Impairment in Schizophrenia: An fMRI and EEG Study.

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.

Acute aerobic exercise enhances cortical connectivity between structures involved in shaping mood and improves self-reported mood: An EEG effective-connectivity study in young male adults.

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.

Implicit induction of emotional control-A comparative fMRI investigation of self-control and reappraisal goal pursuit.

Implicit forms of emotion regulation are of growing interest and have been shown to be efficient in controlling emotional responses despite the fact that they operate without conscious awareness of the ongoing regulatory process and deliberate attempts to influence emotional responding. Although such forms of affective modulation are considered natural and crucial for mental health, their brain mechanisms have hardly been studied until now. Here, we employ a novel procedure and compare directly brain responses to emotional stimuli after implicitly inducing either a self-control goal or a reappraisal goal with a scrambled sentence task. Both induction methods showed robust attenuation of visual, attentional, and emotion-related brain networks. Moreover, after induction of the self-control goal we observed increased activity in the dorsolateral prefrontal cortex (dlPFC) and the right insula, which are involved in top-down modulation of emotional responses. Reappraisal goal induction led to weaker activation in the right dlPFC, which was localized similarly as in the self-control induction task. Our results not only confirm the effectiveness of implicit induction of affective control, but also indicate the important similarities in underlying neural mechanisms that are putatively shared with conscious forms of emotional regulation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Acute aerobic exercise enhances pleasant compared to unpleasant visual scene processing.

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.

The dynamics of pain reappraisal: the joint contribution of cognitive change and mental load.

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.

The influence of mood on visual perception of neutral material.

In the study we investigated how current mood affects spontaneous perceptual processes of neutral stimuli of low­arousal, 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 bottom­up or top­down processes. The observed effects may therefore represent an implicit mechanism of perceptual modulation.

Moderate-intensity exercise boosts the N2 neural inhibition marker: A randomized and counterbalanced ERP study with precisely controlled exercise intensity.

A prior session of moderate intensity continuous exercise (MCE) benefits performance during tasks requiring conflict resolution but the specific cognitive process that underlies this improvement remains unknown. Many studies postulate that MCE increases inhibition, but ERP evidence is ambiguous due to significant differences across past procedures. Most importantly, exercise intensity, which modulates the relationship between acute exercise and cognitive processes, might have varied across past ERP studies. Additionally, previous procedures may not have sufficiently engaged the inhibition process during tasks. The aim of this study was to assess the effects of an acute exercise session on behavioral (accuracy, RT) and ERP (N2, P3b) indices of cognitive processes engaged in conflict resolution. Contrary to most previous studies, we determined ventilatory thresholds (VTD) in order to precisely control exercise metabolism. Moreover, to ensure engagement of inhibition we used a flanker task in a version eliciting strong conflict. 18 male adults underwent three testing sessions in a randomized and counterbalanced order: moderate-intensity continuous exercise (MCE), high-intensity interval exercise (HIIE), and seated rest condition. After each session participants performed the flanker task, during which EEG data was collected. Compared with the control condition, exercise between the first (VT1) and the second (VT2) ventilatory threshold (MCE), but not exercise that exceeded VT2 (HIIE), improved performance in the task and increased the N2 component, which is a neural marker of inhibition. The study shows that MCE might directly benefit inhibition and shows the need for more precise measures of exercise intensity in future studies.

Cognitive conflict increases processing of negative, task-irrelevant stimuli.

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.

Is elaboration of affective content sufficient to attenuate emotional responses during reappraisal procedures?

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.

Top-down and bottom-up competition in visual stimuli processing.

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 bottom­up attention, processing of task­relevant stimuli can be boosted volitionally by top­down attention. Usually, both top­down and bottom­up 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 top­down attention to different extent, whereas processing of background pictures of varying salience engages bottom­up attention to different extent. To check how manipulation of top­down attention influences bottom­up processing, we measured evoked response potentials (ERPs) in response to pictures (engaging mostly bottom­up attention) during three conditions of a letter task (different levels of top­down engagement). Conversely, to check how manipulation of bottom­up attention influences top­down processing, we measured ERP responses for letters (engaging mostly top­down attention) while manipulating the salience of background pictures (different levels of bottom­up engagement). The correctness and reaction times in response to letters were also analyzed. As expected, most of the ERPs and behavioral measures revealed a trade­off between both types of processing: a decrease of bottom­up processing was associated with an increase of top­down processing and, similarly, a decrease of top­down processing was associated with an increase in bottom­up processing. Results proved competition between the two types of attentions.

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.

Towards a constructionist approach to emotions: verification of the three-dimensional model of affect with EEG-independent component analysis.

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.

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.