COMT genotype influences prefrontal response to emotional distraction

Early studies of genetic effects on brain activity have been conducted to investigate primarily either the influence of polymorphisms in dopaminergic genes, especially the catechol-O-methyltransferase (COMT) gene, on prefrontal cognitive processes such as working memory, or that of polymorphisms in the serotonin transporter gene on the amygdala response to threatening stimuli. Here, we address genetic influences on the neural systems underlying cognitive-affective interactions. Specifically, we assess the effect of the COMT val¹⁵⁸met polymorphism on frontal regulation of attention under emotional distraction. Healthy volunteers were scanned while performing a house-matching task with affectively negative versus neutral distractors. Effects of val allele load were examined on frontal regions associated with attentional control and emotion regulation, and on parahippocampal regions associated with perception of houses. As we predicted, val load correlated positively with activity in control- and task-related regions during performance under emotional distraction. These findings provide an initial step toward identifying genetic contributions to interindividual variability in recruitment of mechanisms that regulate affective processing.     

认知重评和表达抑制情绪调节策略的脑网络分析：来自EEG和ERP的证据

本文旨在对认知重评和表达抑制两种常用情绪调节策略的自发脑网络特征及认知神经活动进行深入探讨。研究采集36名在校大学生的静息态和任务态脑电数据, 经过源定位和图论分析发现节点效率与两种情绪调节显著相关的脑区, 以及脑区之间的功能连接。研究结果表明, 在使用认知重评进行情绪调节时会激活前额叶皮质、前扣带回、顶叶、海马旁回和枕叶等多个脑区, 在使用表达抑制进行情绪调节时会激活前额叶皮质、顶叶、海马旁回、枕叶、颞叶和脑岛等多个脑区。因此, 这些脑区的节点效率或功能连接强度可能成为评估个体使用认知重评和表达抑制调节情绪效果的指标。     

Neural substrates for processing task-irrelevant sad images in adolescents

Neural systems related to cognitive and emotional processing were examined in adolescents using event-related functional magnetic resonance imaging (fMRI). Ten healthy adolescents performed an emotional oddball task. Subjects detected infrequent circles (targets) within a continual stream of phase-scrambled images (standards). Sad and neutral images were intermittently presented as task-irrelevant distracters (novels). As previously shown for adults, when the adolescents responded to the task-relevant targets, activation increased in the dorsal attention-executive system including the anterior middle frontal gyrus (aMFG), dorsal anterior cingulate (ACG), posterior cingulate (PCG), insula, and supramarginal gyrus (SMG). Unlike adults, however, the adolescents exhibited strong activation to the emotional distracter images not only in the ventromedial prefrontal cortex (VmPFC), but also in the posterior middle frontal gyrus (pMFG) and in the parietal cortex. Those subjects who had stronger VmPFC activation to emotional distraction also had reduced activation in the aMFG during target detection, suggesting that emotional information may interfere with executive processing in these adolescents. In contrast, pMFG and PCG activation to emotional distracters was positively correlated with aMFG activation to targets, indicating a different role of these regions from the VmPFC. The pattern of activation to task-irrelevant emotional distraction suggests a possible immaturity of brain function in cognitive control over emotional distraction in adolescents.     

Neural correlates of rumination in depression

Rumination, or recursive self-focused thinking, has important implications for understanding the development and maintenance of depressive episodes. Rumination is associated with the worsening of negative mood states, greater affective responding to negative material, and increased access to negative memories. The present study was designed to use fMRI to examine neural aspects of rumination in depressed and healthy control individuals. We used a rumination induction task to assess differences in patterns of neural activation during ruminative self-focus as compared with a concrete distraction condition and with a novel abstract distraction condition in 14 participants who were diagnosed with major depressive disorder and 14 healthy control participants. Depressed participants exhibited increased activation in the orbitofrontal cortex, subgenual anterior cingulate, and dorsolateral prefrontal cortex as compared with healthy controls during rumination versus concrete distraction. Neural activity during rumination versus abstract distraction was greater for depressed than for control participants in the amygdala, rostral anterior cingulate/medial prefrontal cortex, dorsolateral prefrontal cortex, posterior cingulate, and parahippocampus. These findings indicate that ruminative self-focus is associated with enhanced recruitment of limbic and medial and dorsolateral prefrontal regions in depression. Supplemental materials for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.     

Neural activation underlying cognitive control in the context of neutral and affectively charged pictures in children

The neural correlates of cognitive control for typically developing 9-year-old children were examined using dense-array ERPs and estimates of cortical activation (LORETA) during a go/no-go task with two conditions: a neutral picture condition and an affectively charged picture condition. Activation was estimated for the entire cortex after which data were exported for four regions of interests (ROIs): ventrolateral prefrontal cortex (VLPFC), dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (DLPFC), and orbitofrontal/ventromedial prefrontal cortex (OFC/VMPFC). Results revealed faster reaction times, greater N2 activation, and greater prefrontal activation for the affectively charged picture condition than the neutral picture condition. The findings are discussed in reference to the impact of affective stimuli on recruitment of specific brain regions involved in cognitive control.     

Cognitive reappraisal reduces perceived exertion during endurance exercise

Emotion regulation may influence psychological responses to exercise. We examined whether the emotion regulation strategies, cognitive reappraisal and distraction, influenced psychological state and prefrontal cortex oxygenation during endurance exercise. Twenty-four endurance runners ran for 90 min at 75–85% maximum heart rate in three separate sessions with no instruction or with instructions to use cognitive reappraisal or distraction. Participants rated their emotional arousal, emotional valence, and perceived exertion before, every 30 min during, and after exercise. Functional near-infrared spectroscopy quantified changes in prefrontal cortex oxygenation. Participants felt lower emotional arousal and physical exertion when instructed to utilize cognitive reappraisal than when given no emotion regulation instruction. Such responses to distraction did not differ from the other conditions. Emotion regulation strategies did not influence emotional valence or prefrontal cortex oxygenation. Participants’ analytical interpretation of the cognitive reappraisal instruction could contribute to small effect sizes and limited effects. Further research should determine contexts under which emotion regulation strategies most benefit endurance exercise experience.     

Using ERPs to explore the impact of affective distraction on working memory stages in schizophrenia

Research on individuals with schizophrenia (SCZ) shows a variety of emotional and cognitive deficits. We examined the hypothesis that ineffective emotional interference control may impact working memory (WM) performance by disrupting information encoding, maintenance, or retrieval in SCZ. Twenty-eight SCZ and 28 matched healthy controls (HC) performed the visual and verbal delayed-matching-to-sample task (DMST) with trials preceded by negative and nonemotional visual distractors. Event-Related Potentials associated with affective stimuli processing (Late Positive Potential-LPP) and WM-encoding (target-P3), maintenance (Negative Slow Wave-NSW), and retrieval (probe-P3) were analyzed. Patients showed overall worse DMST accuracy than HC. Emotional distraction negatively impacted accuracy during the verbal DMST in both groups combined. Both groups also displayed similar LPP modulation during the presentation of emotional distractors. HC showed enhanced NSW after presentation of a negative distraction, whereas this did not occur in SCZ. Comparable effects of emotional distraction were found for WM-encoding and retrieval in both groups. While emotional and neutral stimuli differentially impacted WM-maintenance on the neural level in HC, we did not observe this effect in SCZ, even though both groups showed similar behavioral and neurophysiological reactions to affective stimuli. Deficits in inhibitory mechanisms in SCZ may be responsible for this effect and may have particular relevance for WM-maintenance difficulties.     

Neural mechanisms of affective interference in schizotypy

Negatively valenced stimuli foster cognitive impairment in schizotypy and schizophrenia. To identify relevant brain mechanisms, the authors had 16 positive-schizotypy and 16 control participants perform an emotional Stroop task, judging the ink color of negative and neutral words during functional magnetic resonance imaging (fMRI) of regional brain activity. Schizotypy individuals showed increased right and decreased left activity in dorsolateral prefrontal cortex, indicating a deficit in maintenance of attentional set in the presence of negative emotional distractors. They also showed abnormal activity in ventral limbic areas, including decreased activity in nucleus accumbens and increased activity in hippocampus and amygdala, a circuit involved in the integration of cognitive and affective processes. These results indicate that aspects of emotion-cognition processes and the brain mechanisms that implement them are similar in schizotypy and schizophrenia.     

The role of medial temporal lobe in item recognition and source recollection of emotional stimuli

Recent neuroimaging results suggest that distinct regions within the medial temporal lobe (MTL) may differentially support the episodic encoding of item and relational information for nonemotional stimuli (for a review, see Davachi, 2006). The present study was designed to assess whether these findings generalize to emotional stimuli. Behaviorally, we found that emotion reduced item recognition accuracy but did not reliably affect relational memory. fMRI analyses revealed that neutral and emotional words elicited distinct activation patterns within MTL regions predictive of subsequent memory. Consistent with previous findings for neutral words, hippocampal activation predicted later relational memory, whereas activation in the perirhinal cortex predicted successful item recognition. However, for emotional words, activation in the amygdala, hippocampus, and posterior parahippocampal cortex predicted item recognition only. These data suggest that MTL regions differentially support encoding of neutral and emotional stimuli.     

The neural correlates of attempting to suppress negative versus neutral memories

We performed an event-related fMRI study comparing attempts at suppressing recall of negative versus neutral memories. The hippocampus is crucial for successful explicit recall. Hippocampal activation has been shown to decrease during the suppression of previously learned neutral words. However, different effects may occur in the case of emotional memories. Participants first learned 40 word pairs consisting of a cue and either a neutral or a negative target. During fMRI scanning, the participants were shown the cues and were instructed to recall the targets or to suppress the targets, using attentional distraction. Similar right-lateralized frontoparietal regions were activated more during suppression than during recall, regardless of emotion. However, we show for the first time that lowered hippocampal activation occurs during the suppression of neutral, but not negative, words. Coinciding with this sustained hippocampal activation, the amygdala, insula, anterior cingulate, and fusiform gyrus showed greater activation during the suppression of negative memories than during suppression of neutral memories. Thus, during attempts to suppress negative memories, regions involved in the emotional and sensory aspects of memory reactivate, along with regions indexing conscious recall. Revealing the neural correlates and mechanisms of the suppression of negative memories has relevance for disorders such as posttraumatic stress disorder, in which traumatic memories often intrude and are associated with avoidance. Supplemental materials for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.     

Ecstasy and agony: activation of the human amygdala in positive and negative emotion

Considerable evidence indicates that the amygdala plays a critical role in negative, aversive human emotions. Although researchers have speculated that the amygdala plays a role in positive emotion, little relevant evidence exists. We examined the neural correlates of positive and negative emotion using positron emission tomography (PET), focusing on the amygdala. Participants viewed positive and negative photographs, as well as interesting and uninteresting neutral photographs, during PET scanning. The left amygdala and ventromedial prefrontal cortex were activated during positive emotion, and bilateral amygdala activation occurred during negative emotion. High-interest, unusual photographs also elicited left-amygdala activation, a finding consistent with suggestions that the amygdala is involved in vigilance reactions to associatively ambiguous stimuli. The current results constitute the first neuroimaging evidence for a role of the amygdala in positive emotional reactions elicited by visual stimuli. Although the amygdala appears to play a more extensive role in negative emotion, it is involved in positive emotion as well.     

Attention, emotion, and deactivation of default activity in inferior medial prefrontal cortex

Attention deactivates the inferior medial prefrontal cortex (IMPC), but it is uncertain if emotions can attenuate this deactivation. To test the extent to which common emotions interfere with attention, we measured changes of a blood flow index of brain activity in key areas of the IMPC with positron emission tomography (PET) of labeled water (H(15)2O) uptake in brain of 14 healthy subjects. The subjects performed either a less demanding or a more demanding task of attention while they watched neutral and emotive images of people in realistic indoor or outdoor situations. In the less demanding task, subjects used the index finger to press any key when a new image appeared. In the more demanding task, subjects chose the index or middle finger to press separate keys for outdoor and indoor scenes. Compared to the less demanding task, in a global search of all gray matter, the more demanding significantly lowered blood flow (rCBF) in left IMPC, left and right insula, and right amygdala, and significantly raised blood flow in motor cortex and right precuneus. Restricted searches of rCBF changes by emotion, at coordinates of significant effect in previous studies of the medial prefrontal and temporal cortices, revealed significant activation in the fusiform gyrus, independently of the task. In contrast, we found no effect of emotional content in the IMPC, where emotions failed to override the effect of the task. The results are consistent with a role of the IMPC in the selection among competitive inputs from multiple brain regions, as predicted by the theory of a default mode of brain function. The absent emotional interference with the deactivation of the default state suggests that the inferior prefrontal cortex continued to serve the attention rather than submit to the distraction.     

Effects of Aging on Functional Connectivity of the Amygdala for Subsequent Memory of Negative Pictures: A Network Analysis of Functional Magnetic Resonance Imaging Data

ABSTRACT— Aging is associated with preserved enhancement of emotional memory, as well as with age-related reductions in memory for negative stimuli, but the neural networks underlying such alterations are not clear. We used a subsequent-memory paradigm to identify brain activity predicting enhanced emotional memory in young and older adults. Activity in the amygdala predicted enhanced emotional memory, with subsequent-memory activity greater for negative stimuli than for neutral stimuli, across age groups, a finding consistent with an overall enhancement of emotional memory. However, older adults recruited greater activity in anterior regions and less activity in posterior regions in general for negative stimuli that were subsequently remembered. Functional connectivity of the amygdala with the rest of the brain was consistent with age-related reductions in memory for negative stimuli: Older adults showed decreased functional connectivity between the amygdala and the hippocampus, but increased functional connectivity between the amygdala and dorsolateral prefrontal cortices. These findings suggest that age-related differences in the enhancement of emotional memory might reflect decreased connectivity between the amygdala and typical subsequent-memory regions, as well as the engagement of regulatory processes that inhibit emotional responses.     

抑郁症患者工作记忆内情绪刺激加工的特点及其机制

抑郁症患者在工作记忆内情绪刺激加工的特点为倾向于加工与负性心境一致的材料, 被认为是抑郁症认知易感性的核心特征。目前研究者们围绕抑郁症工作记忆中央执行系统三个子功能的情绪刺激加工特点及其作用机制进行了大量研究, 发现在更新功能上, 患者难以移除负性情绪信息, 且在正性信息的加工上存在缺损; 在抑制功能上, 患者难以抑制无关负性情绪信息进入工作记忆; 在转换功能上, 患者情绪材料转换困难的研究证据尚不充分。神经生理与脑成像的研究初步表明, 工作记忆中的情绪刺激加工与抑郁症患者背外侧前额叶和前扣带回的功能激活水平异常有关。未来研究需评估工作记忆三个子功能对抑郁症状的差异性贡献及在情绪刺激加工上的统一性, 并探究其随疾病发生发展变化的轨迹, 谨慎选取并评估不同情绪刺激材料指标的诱发效应及其对工作记忆功能的独特影响。在此基础上, 深入探究工作记忆内情绪刺激加工的神经机制, 为工作记忆偏向矫正干预的临床应用及其预期效果提供理论依据和方向。     

Age differences in the neural response to emotional distraction during working memory encoding

Age-related declines in attention and working memory (WM) are well documented and may be worsened by the occurrence of distracting information. Emotionally valenced stimuli may have particularly strong distracting effects on cognition. We investigated age-related differences in emotional distraction using task-fMRI. WM performance in older adults was lower for emotional compared with neutral distractors, suggesting a disproportional impairment elicited by emotional task-irrelevant information. Critically, older adults were particularly distracted by task-irrelevant positive information, whereas the opposite pattern was found for younger adults. Age groups differed markedly in the brain response to emotional distractors; younger adults activated posterior cortical regions and the striatum, and older adults activated frontal regions. Also, an age by valence interaction was found for IFG and ACC, suggesting differential modulation of attention to task-relevant emotional information. These results provide new insights into age-related changes in emotional processing and the ability to resolve interference from emotional distraction.     

On the relationship between negative affective priming and prefrontal cognitive control mechanisms

Although several studies have examined inhibition of affective stimuli, valence-dependent cognitive control effects remain poorly understood. Behavioural and functional imaging (functional magnetic resonance imaging) data were collected from 17 healthy participants to examine neural correlates of the Negative Affective Priming (NAP) task. We created relative ratio scores considering the reaction times of prime trials in order to assess the amount of interference after the presentation of negative and positive distracter words. Behavioural results showed an attenuated NAP effect for negative distracters compared to neutral stimuli. Furthermore, priming negative distracters generated more interference by reacting to the probe target than positive distracters. Neuroimaging data revealed a stronger prefrontal activation during negative NAP trials compared to positive NAP and neutral control trials, which was reflected in a heightened activation of superior and middle frontal gyrus as well as parietal cortex. The findings show the impact of negative distracters on prefrontal response, contributing to the understanding of NAP effects in healthy subjects.     

The neurodevelopmental basis of math anxiety

Math anxiety is a negative emotional reaction to situations involving mathematical problem solving. Math anxiety has a detrimental impact on an individual's long-term professional success, but its neurodevelopmental origins are unknown. In a functional MRI study on 7- to 9-year-old children, we showed that math anxiety was associated with hyperactivity in right amygdala regions that are important for processing negative emotions. In addition, we found that math anxiety was associated with reduced activity in posterior parietal and dorsolateral prefrontal cortex regions involved in mathematical reasoning. Multivariate classification analysis revealed distinct multivoxel activity patterns, which were independent of overall activation levels in the right amygdala. Furthermore, effective connectivity between the amygdala and ventromedial prefrontal cortex regions that regulate negative emotions was elevated in children with math anxiety. These effects were specific to math anxiety and unrelated to general anxiety, intelligence, working memory, or reading ability. Our study identified the neural correlates of math anxiety for the first time, and our findings have significant implications for its early identification and treatment.     

Neural mechanisms of interference control underlie the relationship between fluid intelligence and working memory span

Fluid intelligence (gF) and working memory (WM) span predict success in demanding cognitive situations. Recent studies show that much of the variance in gF and WM span is shared, suggesting common neural mechanisms. This study provides a direct investigation of the degree to which shared variance in gF and WM span can be explained by neural mechanisms of interference control. The authors measured performance and functional magnetic resonance imaging activity in 102 participants during the n-back WM task, focusing on the selective activation effects associated with high-interference lure trials. Brain activity on these trials was correlated with gF, WM span, and task performance in core brain regions linked to WM and executive control, including bilateral dorsolateral prefrontal cortex (middle frontal gyrus; BA9) and parietal cortex (inferior parietal cortex; BA 40/7). Interference-related performance and interference-related activity accounted for a significant proportion of the shared variance in gF and WM span. Path analyses indicate that interference control activity may affect gF through a common set of processes that also influence WM span. These results suggest that individual differences in interference-control mechanisms are important for understanding the relationship between gF and WM span.