Anticipation of conflict monitoring in the anterior cingulate cortex and the prefrontal cortex

Altered Functional Connectivity of the Multisensory Vestibular Cortex in Patients with Chronic Unilateral Vestibulopathy

Background: Chronic unilateral vestibulopathy (CUVP) is a common chronic vestibular syndrome; the mechanisms of central vestibular compensation in CUVP are rarely studied. Methods: This study analyzed the data of 18 patients with CUVP and 18 healthy controls (HCs) and used seed-based functional connectivity (FC) and voxel-mirrored homotopic connectivity (VMHC) analyses to explore the FC alterations. Results: Compared with HCs, patients with CUVP showed decreased FC between the left dorsolateral superior frontal gyrus and the right hippocampus; the left middle frontal gyrus and the right posterior cingulate gyrus, the right hippocampus, the right parahippocampal gyrus. There is also a reduction in FC between the left and right insula. There was enhanced FC between the left supplementary motor area (SMA) and the bilateral superior occipital gyrus, the left hippocampus and the left posterior cingulate gyrus, as well as a the left middle temporal gyrus (p = 0.03). Additionally,VMHC was decreased between the bilateral medial superior frontal gyrus, the bilateral precentral gyrus, and the bilateral postcentral gyrus (p = 0.001). The zVMHC values in the bilateral superior frontal gyrus and the precentral gyrus were both negatively corrected with the Dizziness Handicap Inventory (DHI) score.well as Conclusions: Altered FC in regions of bilateral multisensory vestibular cortex existed in patients with CUVP. Decreased FC and VMHC in the bilateral multisensory vestibular cortex may affect vestibular information integration, thus affecting self-motion perception, spatial orientation, and postural control.

Disruptions of salience network during uncertain anticipation of conflict control in anxiety

BACKGROUND

Anxiety has been characterized by disrupted processing of conflict control, while little is known about anticipatory processing of conflicts in anxiety. Anticipation is the key factor in both anxiety and cognitive control, especially under uncertain conditions. The current study therefore examined neurocomputational mechanisms of uncertain anticipation of conflict control in anxiety.

METHODS

Twenty-six participants with high-trait anxiety and twenty-nine low-trait anxiety participants completed a cue-flanker task with functional magnetic resonance imaging. The hierarchical drift diffusion model (HDDM) was used to measure the cognitive computations during the task. To identify the neurocomputational mechanism of anticipatory control in anxiety, mediation analysis and dynamic causal modelling (DCM) analysis were conducted to examine the relationship between functional connectivity of brain networks and the parameters of HDDM.

RESULTS

We found influences of regulatory signals from the dorsolateral prefrontal cortex to dorsal anterior cingulate cortex on decision threshold in low-trait anxiety (LTA), but not in high-trait anxiety (HTA), especially for the condition with uncertain cues. The results indicate deficient top-down anticipatory control of upcoming conflicts in anxious individuals. DCM and HDDM analyses revealed that lower decision threshold was associated with higher intrinsic connectivity of salience network (SN) in anxious individuals, suggesting that dysfunctional SN disrupts anticipation of conflict control under uncertainty in anxiety.

CONCLUSIONS

Our results suggest hyperfunction of the SN underlies the deficient information accumulation during uncertain anticipation of upcoming conflicts in anxiety. Our findings shed new light on the mechanisms of anticipation processing and the psychopathology of anxiety.

Mind-wandering does not always rhyme with proactive functioning! Changes in the temporal dynamics of the mPFC-mediated theta oscillations during moments of mind-wandering

The reduced engagement of the cognitive control network has been documented widely during mind-wandering (MW). However, it remains unknown how MW affects the neural dynamics of cognitive control processes. From this perspective, we explored neural dynamics mediated by the medial prefrontal cortex (mPFC). Their engagement can be both transient (or reactive) and anticipated (or proactive). A total of fortyseven healthy subjects (37 females) were engaged in a long-lasting sustained-attention Go/NoGo task. Subjective probes were used to detect MW episodes. Channel-based EEG time-frequency analysis was performed to measure the theta oscillations, an index of the mPFC activity. The theta oscillations were computed immediately after conflictual NoGo trials to explore the reactive engagement of the mPFC. Proactive control was measured on the Go trials preceded the NoGo. Behaviorally, periods of MW were associated with an increase in errors and in RT variability in comparison to on-task periods. The analysis of the frontal midline theta power (MFθ) revealed that MW periods were associated with lower anticipated/proactive engagement and similar transient/reactive engagement of mPFC-mediated processes. Moreover, the communication between the mPFC and the DLPFC, as revealed by the poorer theta synchronization between these two regions, was also impaired during MW periods. Our results provide new insights about performance impairment during MW. They could be an important step in improving the existing understanding of the altered performances that are reported for some disorders that are known to be associated with excessive MW.

Increased spontaneous activity of the superior frontal gyrus with reduced functional connectivity to visual attention areas and cerebellum in male smokers

Background

Chronic smokers have abnormal spontaneous regional activity and disrupted functional connectivity as revealed by previous neuroimaging studies. Combining different dimensions of resting-state functional indicators may help us learn more about the neuropathological mechanisms of smoking.

Methods

The amplitude of low frequency fluctuations (ALFF) of 86 male smokers and 56 male non-smokers were first calculated. Brain regions that displayed significant differences in ALFF between two groups were selected as seeds for further functional connectivity analysis. Besides, we examined correlations between brain areas with abnormal activity and smoking measurements.

Results

Increased ALFF in left superior frontal gyrus (SFG), left medial superior frontal gyrus (mSFG) and middle frontal gyrus (MFG) as well as decreased ALFF in right calcarine sulcus were observed in smokers compared with non-smokers. In the seed-based functional connectivity analysis, smokers showed attenuated functional connectivity with left SFG in left precuneus, left fusiform gyrus, left lingual gyrus, left cerebellum 4 5 and cerebellum 6 as well as lower functional connectivity with left mSGF in left fusiform gyrus, left lingual gyrus, left parahippocampal gyrus (PHG), left calcarine sulcus, left cerebellum 4 5, cerebellum 6 and cerebellum 8 (GRF corrected, Pvoxel < 0.005, Pcluster<0.05). Furthermore, attenuated functional connectivity with left mSGF in left lingual gyrus and PHG displayed a negative correlation with FTND scores (r = −0.308, p = 0.004; r = −0.326, p = 0.002 Bonferroni corrected).

Conclusion

Our findings of increased ALFF in SFG with reduced functional connectivity to visual attention areas and cerebellum subregions may shed new light on the pathophysiology of smoking.

Unconscious Conflict Adaptation of Heroin Abstainers

Conflict adaptation is representative of the dynamic cognitive control process, which reflects the adaptability and flexibility of personal cognitive processing. Cognitive control plays an important role in drug use and relapse in addicts. Previous studies have identified conscious conflict adaptation in drug addicts. The present study examined unconscious conflict adaptation in persons with heroin use disorder using an arrow version meta-contrast masking task. The results found that persons with heroin use disorder had smaller unconscious conflict adaptation compared to the healthy control group. This may be a result of functional brain damage caused by long-term drug use.

False memory confidence depends on the prefrontal reinstatement of true memory

For confidence of memory, a neural basis such as traces of stored memories should be required. However, because false memories have never been stored, the neural basis for false memory confidence remains unclear. Here we monitored the brain activity in participants while they viewed learned or novel objects, subsequently decided whether each presented object was learned and assessed their confidence levels. We found that when novel objects are presented, false memory confidence significantly depends on the shared representations with learned objects in the prefrontal cortex. However, such a tendency was not found in posterior regions including the visual cortex, which may be involved in the processing of perceptual gist. Furthermore, the confidence-dependent shared representations were not observed when participants correctly answered novel objects as non-learned objects. These results demonstrate that false memory confidence is critically based on the reinstatement of high-level semantic gist of stored memories in the prefrontal cortex.

The interaction between depression diagnosis and BMI is related to altered activation pattern in the right inferior frontal gyrus and anterior cingulate cortex during food anticipation

BACKGROUND

Depression and overweight/obesity often cooccur but the underlying neural mechanisms for this bidirectional link are not well understood.

METHODS

In this functional magnetic resonance imaging study, we scanned 54 individuals diagnosed with depressive disorders (DD) and 48 healthy controls (HC) to examine how diagnostic status moderates the relationship between body mass index (BMI) and brain activation during anticipation and pleasantness rating of food versus nonfood stimuli.

RESULTS

We found a significant BMI-by-diagnosis interaction effect on activation in the right inferior frontal gyrus (RIFG) and anterior cingulate cortex (ACC) during food versus nonfood anticipation (p < .0125). Brain activation in these regions was greater in HC with higher BMI than in HC with lower BMI. Individuals with DD showed an opposite pattern of activation. Structural equation modeling revealed that the relationship between BMI, activation in the RIFG and ACC, and participants' desire to eat food items shown in the experiment depended on the diagnostic status.

CONCLUSIONS

Considering that food anticipation is an important component of appetitive behavior and that the RIFG and ACC are involved in emotion regulation, response inhibition and conflict monitoring necessary to control this behavior, we propose that future clinical trials targeting weight loss in DD should investigate whether adequate mental preparation positively affects subsequent food consumption behaviors in these individuals.

Value, Confidence, Deliberation: A Functional Partition of the Medial Prefrontal Cortex Demonstrated across Rating and Choice Tasks

Deciding about courses of action involves minimizing costs and maximizing benefits. Decision neuroscience studies have implicated both the ventral and dorsal medial PFC (vmPFC and dmPFC) in signaling goal value and action cost, but the precise functional role of these regions is still a matter of debate. Here, we suggest a more general functional partition that applies not only to decisions but also to judgments about goal value (expected reward) and action cost (expected effort). In this conceptual framework, cognitive representations related to options (reward value and effort cost) are dissociated from metacognitive representations (confidence and deliberation) related to solving the task (providing a judgment or making a choice). We used an original approach aimed at identifying consistencies across several preference tasks, from likeability ratings to binary decisions involving both attribute integration and option comparison. fMRI results in human male and female participants confirmed the vmPFC as a generic valuation system, its activity increasing with reward value and decreasing with effort cost. In contrast, more dorsal regions were not concerned with the valuation of options but with metacognitive variables, confidence being reflected in mPFC activity and deliberation time in dmPFC activity. Thus, there was a dissociation between the effort attached to choice options (represented in the vmPFC) and the effort invested in deliberation (represented in the dmPFC), the latter being expressed in pupil dilation. More generally, assessing commonalities across preference tasks might help in reaching a unified view of the neural mechanisms underlying the cost/benefit tradeoffs that drive human behavior.SIGNIFICANCE STATEMENT Decision neuroscience studies have implicated the medial PFC in forming the cognitive representations that drive human choice behavior. However, different studies using different tasks have suggested somewhat inconsistent links between precise computational variables and specific brain regions. Here, we use fMRI to demonstrate a robust functional partition of the medial PFC that generalizes across tasks involving an estimation of goal value and/or action cost to provide a judgment or make a choice. This general functional partition makes a critical dissociation between neural representations of decisional factors (the expected costs and benefits attached to a given option) and metacognitive estimates (confidence in the judgment or choice, and effort invested in the deliberation process).

Neural Underpinnings of Proactive and Preemptive Adjustments of Action Control

This study aimed to trace the neural basis of proactive and preemptive adjustments of executive control and their effects on online processing of response conflict. In two EEG experiments, participants performed the flanker task with predictive cueing of conflict. The following questions were addressed: "Does conflict cueing improve performance?" We observed improved behavioral performance in the predictive condition, suggesting that participants proactively utilized the cues to prepare for the upcoming demands. "How is conflict processing affected by predictive cueing?" Conflict-related modulations of midfrontal N2 and theta power were smaller in the predictive than in the neutral condition. This suggests that proactive control suppressed the impact of incongruent flankers so that the conflict was reduced, and so was the involvement of online control. "Is proactive control implemented through preactivation of online control?" Conflict cueing increased midfrontal theta power also before target onset, suggesting preactivation of the control processes beforehand. "Do proactive and reactive control depend on common or unique processes?" Unlike the online control, the proactive control triggered a burst of theta power in the right hemisphere's dorsal and ventral lateral prefrontal cortices, connected with the midfrontal area via theta phase coherence. This indicates that the two control modes involve partially unique but coordinated neural processes. "Is preemptive control implemented through modulations of visual processing?" Predictive cueing modulated both the pretarget preparatory alpha desynchronization and the target selection-related posterior contralateral negativity (N2pc and sustained posterior contralateral negativity), in line with the hypothesis of preemptive tuning of sensory selection aimed at reducing the impact of conflicting stimuli.

Concurrent brain structural and functional alterations in patients with chronic unilateral vestibulopathy

BACKGROUND

Chronic unilateral vestibulopathy (CUVP) is a common chronic vestibular syndrome which may be caused by incomplete vestibular dynamic compensation. Neuroimaging technology provides important clues to explore the mechanism of complicated by vestibular dynamic compensation in patients with CUVP. However, previous studies mostly used positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to investigate the changes of brain function in these patients during the task state, few studies have investigated the alterations during the resting state, Therefore, the study aimed to investigate the possible brain structural and functional alterations in patients with CUVP and explore the dynamic compensation state in patients with CUVP.

METHODS

We recruited 18 patients with right CUVP and 18 age-, gender-, and education level-matched healthy controls (HCs). Vestibular evaluations, such as videonystagmography and caloric tests, were performed. All participants underwent Dizziness Handicap Inventory (DHI) assessment. All participants underwent multimodal magnetic resonance imaging of the brain, including fMRI and three-dimensional T1-weighted MRI. We analyzed the amplitude of low frequency fluctuations (ALFF), regional homogeneity (ReHo), seed based functional connectivity, and voxel-based morphometry (VBM).

RESULTS

Compared with HCs, CUVP patients showed significantly increased ALFF values in the right supplementary motor area, significantly decreased ALFF values in the right middle occipital gyrus, significantly decreased ReHo values in the bilateral superior parietal lobule, and significantly enhanced ReHo values in the bilateral cerebellar hemisphere [both P<0.05, family-wise error (FWE) corrected]. Compared with HCs, patients with CUVP showed increased gray matter volumes in the left medial superior frontal gyrus and left middle cingulate gyrus [P<0.001, false discovery rate (FDR) corrected]. Compared with HCs, in patients with CUVP, functional connectivity was enhanced between the left medial superior frontal gyrus and the left orbital inferior frontal gyrus and left angular gyrus and was significantly decreased between the left medial superior frontal gyrus and the right dorsolateral superior frontal gyrus (both P<0.01, FWE corrected). Pearson correlation analysis showed that there was a positive correlation between DHI score and VBM value of the left medial superior frontal gyrus in patients with CUVP (r=-0.430, P=0.003).

CONCLUSIONS

This study identified abnormalities of neuronal activity intensity and overall activity synchronization in multiple brain regions in patients with CUVP, suggesting that patients with CUVP have extensive brain functional abnormalities, which in turn affects their spatial perception and motor perception. Increased gray matter volume and functional connectivity of the default mode network may be used as potential imaging biomarkers of chronic symptoms in patients with CUVP.

Frequency-domain analysis of fNIRS fluctuations induced by rhythmic mental arithmetic

Functional near‐infrared spectroscopy (fNIRS) is an increasingly used technology for imaging neural correlates of cognitive processes. However, fNIRS signals are commonly impaired by task‐evoked and spontaneous hemodynamic oscillations of non‐cerebral origin, a major challenge in fNIRS research. In an attempt to isolate the task‐evoked cortical response, we investigated the coupling between hemodynamic changes arising from superficial and deep layers during mental effort. For this aim, we applied a rhythmic mental arithmetic task to induce cyclic hemodynamic fluctuations suitable for effective frequency‐resolved measurements. Twenty university students aged 18–25 years (eight males) underwent the task while hemodynamic changes were monitored in the forehead using a newly developed NIRS device, capable of multi‐channel and multi‐distance recordings. We found significant task‐related fluctuations for oxy‐ and deoxy‐hemoglobin, highly coherent across shallow and deep tissue layers, corroborating the strong influence of surface hemodynamics on deep fNIRS signals. Importantly, after removing such surface contamination by linear regression, we show that the frontopolar cortex response to a mental math task follows an unusual inverse oxygenation pattern. We confirm this finding by applying for the first time an alternative method to estimate the neural signal, based on transfer function analysis and phasor algebra. Altogether, our results demonstrate the feasibility of using a rhythmic mental task to impose an oscillatory state useful to separate true brain functional responses from those of non‐cerebral origin. This separation appears to be essential for a better understanding of fNIRS data and to assess more precisely the dynamics of the neuro‐visceral link.

We proposed the use of rhythmic mental arithmetic tasks to induce cyclic oscillations in multi‐distance fNIRS signals measured on the forehead, suitable for effective frequency‐domain analysis to better identify the actual neural functional response. We confirm the impairment of deep signals by task‐evoked non‐cerebral confounds, while providing evidence for an inverse oxygenation response in the frontopolar cortex.

Temporally and functionally distinct large-scale brain network dynamics supporting task switching

Objective:

Our daily activities require frequent switches among competing responses at the millisecond time scale. We determined the spatiotemporal characteristics and functional significance of rapid, large-scale brain network dynamics during task switching.

Methods:

This cross-sectional study investigated patients with drug-resistant focal epilepsy who played a Lumosity cognitive flexibility training game during intracranial electroencephalography (iEEG) recording. According to a given task rule, unpredictably switching across trials, participants had to swipe the screen in the direction the stimulus was pointing or moving. Using this data, we described the spatiotemporal characteristics of iEEG high-gamma augmentation occurring more intensely during switch than repeat trials, unattributable to the effect of task rule (pointing or moving), within-stimulus congruence (the direction of stimulus pointing and moving was same or different in a given trial), or accuracy of an immediately preceding response. Diffusion-weighted imaging (DWI) tractography determined whether distant cortical regions showing enhanced activation during task switch trials were directly connected by white matter tracts. Trial-by-trial iEEG analysis deduced whether the intensity of task switch-related high-gamma augmentation was altered through practice and whether high-gamma amplitude predicted the accuracy of an upcoming response among switch trials.

Results:

The average number of completed trials during five-minute gameplay was 221.4 per patient (range: 171–285). Task switch trials increased the response times, whereas later trials reduced them. Analysis of iEEG signals sampled from 860 brain sites effectively elucidated the distinct spatiotemporal characteristics of task switch, task rule, and post-error-specific high-gamma modulations. Post-cue, task switch-related high-gamma augmentation was initiated in the right calcarine cortex after 260 ms, right precuneus after 330 ms, right entorhinal after 420 ms, and bilateral anterior middle-frontal gyri after 450 ms. DWI tractography successfully showed the presence of direct white matter tracts connecting the right visual areas to the precuneus and anterior middle-frontal regions but not between the right precuneus and anterior middle-frontal regions. Task-related high-gamma amplitudes in later trials were reduced in the calcarine, entorhinal and anterior middle-frontal regions, but increased in the precuneus. Functionally, enhanced post-cue precuneus high-gamma augmentation improved the accuracy of subsequent responses among switch trials.

Conclusions:

Our multimodal analysis uncovered two temporally and functionally distinct network dynamics supporting task switching. High-gamma augmentation in the visual-precuneus pathway may reflect the neural process facilitating an attentional shift to a given updated task rule. High-gamma activity in the visual-dorsolateral prefrontal pathway, rapidly reduced through practice, may reflect the cost of executing appropriate stimulus-response translation.

The anterior cingulate cortex directly enhances auditory cortical responses in air-puffing-facilitated flight behavior

For survival, animals encode prominent events in complex environments, which modulates their defense behavior. Here, we design a paradigm that assesses how a mild aversive cue (i.e., mild air puff) interacts with sound-evoked flight behavior in mice. We find that air puffing facilitates sound-evoked flight behavior by enhancing the auditory responses of auditory cortical neurons. We then find that the anterior part of the anterior cingulate cortex (ACC) encodes the valence of air puffing and modulates the auditory cortex through anatomical examination, physiological recordings, and optogenetic/chemogenetic manipulations. Activating ACC projections to the auditory cortex simulates the facilitating effect of air puffing, whereas inhibiting the ACC or its projections to the auditory cortex neutralizes this facilitating effect. These findings show that the ACC regulates sound-evoked flight behavior by potentiating neuronal responses in the auditory cortex.

Exploring behavioural and cognitive dysexecutive syndrome in patients with focal prefrontal cortex damage

This study's objectives were to characterize the frequency and profile of behavioral and cognitive dysexecutive syndromes in patients with focal prefrontal cortex damage and how these syndromes overlap. We also examined the contribution of the prefrontal brain regions to these syndromes. Therefore, thirty patients with prefrontal cortex damage and thirty control subjects were compared on their performances using the GREFEX battery assessing the dysexecutive syndromes. The results showed that combined behavioral and cognitive dysexecutive syndrome was observed in 53.33%, while pure cognitive dysexecutive syndrome was observed in 20% and behavioral in 26.67%. Also, almost all behavioral and cognitive dysexecutive disorders discriminated frontal patients from controls. Moreover, correlations and regression analyses between task scores in both domains of dysexecutive syndromes showed that the spectrum of behavioral disorders was differentially associated with cognitive impairment of initiation, inhibition, generation, deduction, coordination, flexibility and the planning process. Furthermore, the patterns of cognitive and behavioral dysexecutive syndrome were both predictors of impairment in daily living activities and loss of autonomy. Finally, frontal regions contributing to different dysexecutive syndromes assessed by MRI voxel lesion symptom analysis indicate several overlapping regions centered on the ventromedial and dorsomedial prefrontal cortex for both domains of dysexecutive syndrome. This study concludes that damage to the frontal structures may lead to a diverse set of changes in both cognitive and behavioral domains which both contribute to loss of autonomy. The association of the ventromedial and dorsomedial prefrontal regions to both domains of dysexecutive syndrome suggests a higher integrative role of these regions in processing cognition and behavior.

Global Functional Connectivity Analysis Indicating Dysconnectivity of the Hate Circuit in Major Depressive Disorder

Background

Abnormalities of functional connectivity (FC) in certain brain regions are closely related to the pathophysiology of major depressive disorder (MDD). Findings are inconsistent with different presuppositions in regions of interest. Our research focused on voxel-wise brain-wide FC changes in patients with MDD in an unbiased manner.

Method

We examined resting-state functional MRI in 23 patients with MDD and 26 healthy controls. Imaging data were analyzed by using global-brain FC (GFC) and used to explore the correlation of abnormal GFC values with clinical variables.

Results

Increased GFC values in the left medial superior frontal gyrus (SFGmed) and decreased GFC values in the right supplementary motor area (SMA) were observed in the patients with MDD compared with the controls. The decreased GFC values in the right SMA had a positive correlation with vitamin D and Hamilton Anxiety Scale (HAM-A) scores.

Conclusion

Abnormal GFC in the hate circuit, particularly increased GFC in the left SFGmed and decreased GFC in the right SMA, appears to be a new sight for comprehending the pathological alterations in MDD.

Decreased preparatory activation and inattention to cues suggest lower activation of proactive cognitive control among high procrastinating students

Procrastination is a voluntary delay in completing an important task while being aware that this behavior may lead to negative outcomes. It has been shown that an increased tendency to procrastinate is associated with deficits in some aspects of cognitive control. However, none of the previous studies investigated these dysfunctions through the lenses of the Dual Mechanisms Framework, which differentiates proactive and reactive modes of control. The present study was designed to fill this gap, using behavioral and neurophysiological assessment during the completion of the AX-Continuous Performance Task (AX-CPT) by high (HP) and low (LP) procrastinating students (N = 139). Behavioral results indicated that HP (vs. LP) were characterized by increased attentional fluctuations (higher reaction time variability) and reduction in some indices of proactive cognitive control (lower d'-context and A-cue bias, but similar PBIs). Furthermore, the neurophysiological data showed that HP, compared with LP, allocated less attentional resources (lower P3b) to cues that help to predict the correct responses to upcoming probes. They also responded with reduced preparatory activity (smaller CNV) after cues presentation. The two groups did not differ in neural responses linked to conflict detection and inhibition (similar N2 and P3a). Obtained findings indicate that HP might present deficits in some cognitive functions that are essential for effective proactive control engagement, along with preserved levels of reactive cognitive control. In the present paper, we discuss the potential neural and cognitive mechanisms responsible for the observed effects.

Moral Conflict in Economic Decision Making: The Role of the Anterior Cingulate Cortex-Striatum Pathway

The present study combined a novel hypothetical investment game with functional magnetic resonance imaging to examine how moral conflict biases our real decision preference when it is not obvious or explicitly presented. Investment projects were chosen based on their prior subjective morality ratings to fit into 2 categories: a high level of moral conflict (HMC) or a low level of moral conflict (LMC). Participants were instructed to invest high or low amounts of capital into different projects. Behavioral and neural responses during decision making were recorded and compared. Behaviorally, we observed a significant decision bias such that investments were lower for HMC projects than for LMC projects. At the neural level, we found that moral conflict-related activity in the anterior cingulate cortex (ACC) was higher in the HMC condition than in the LMC condition and that reward-related activity in bilateral striatum was lower. Dynamic causal modeling further suggested that the moral conflict detected in the ACC influenced final decisions by modulating the representation of subjective value through the ACC's connection to the reward system.

Neural correlates of alcohol use disorder severity among nontreatment-seeking heavy drinkers: An examination of the incentive salience and negative emotionality domains of the alcohol and addiction research domain criteria

BACKGROUND

The Alcohol and Addiction Research Domain Criteria (AARDoC) propose that alcohol use disorder is associated with neural dysfunction in three primary domains: incentive salience, negative emotionality, and executive function. Prior studies in heavy drinking samples have examined brain activation changes associated with alcohol and negative affect cues, representing the incentive salience and negative emotionality domains, respectively. Yet studies examining such cue-induced changes in functional connectivity (FC) are relatively sparse.

METHODS

Nontreatment-seeking heavy drinking adults (N = 149, 56.0% male, 48.6% non-white, mean age 34.8 years (SD = 10.0)) underwent functional magnetic resonance imaging during presentation of alcohol, negative, and neutral pictures. We focused on FC changes involving the nucleus accumbens and amygdala in addition to activation and FC correlations with self-reported AUD severity.

RESULTS

For alcohol cues versus neutral cues, we observed accumbens FC changes in the cerebellum and prefrontal cortex (PFC), and amygdala FC changes with occipital, parietal, and hippocampal regions. AUD severity correlated positively with activation in the cerebellum (p < 0.05), accumbens FC in the cingulate gyri, somatosensory gyri, and cerebellum (p < 0.05), and with amygdala FC in the PFC and inferior parietal lobule (p < 0.05) for alcohol cues versus neutral cues. For negative cues versus neutral cues, we observed accumbens FC changes in the lateral temporal, occipital, and parietal regions, and amygdala FC changes in the fusiform and lingual gyri (p < 0.05).

CONCLUSIONS

The present findings provide empirical support for the AARDoC domains of incentive salience and negative emotionality and indicate that AUD severity is associated with salience and response control for reward cues. When covarying for differences in nonalcohol substance use and mood disorder diagnoses, AUD severity was also associated with emotional reactivity for negative cues.

Changes in neural reward processing following Amplification of Positivity treatment for depression and anxiety: Preliminary findings from a randomized waitlist controlled trial

Positive valence system (PVS) deficits are increasingly recognized as important treatment targets for depression and anxiety. Emerging behavioral treatments designed to upregulate the PVS show initial promise; however, neural mechanisms underlying these approaches remain unknown. This study investigated neural reward-processing-related changes following Amplification of Positivity (AMP)-a treatment designed to enhance positive thinking, emotions and behaviors through positive activity interventions (Clinicaltrials.gov: NCT02330627). Individuals with depression and/or anxiety (N = 29) were randomized to 10 sessions of AMP (n = 16) or waitlist (WL; n = 13). Participants completed a monetary incentive delay task during fMRI at baseline and post-assessment. Hypothesis-driven region of interest (ventral striatum, insula, anterior cingulate) and exploratory whole-brain activation and connectivity analyses evaluated pre-to-post changes for AMP vs. WL when anticipating potential monetary gain or loss. No between-group brain activation changes emerged in regions of interest or whole-brain analyses. Increased neural connectivity from pre-to-post-treatment was observed in AMP vs. WL, including ventral striatum, anterior insula, and anterior cingulate connectivity with prefrontal, limbic, occipital and parietal regions-predominantly during loss anticipation. This preliminary study is the first to examine neural mechanisms of positive activity interventions in depression and anxiety and suggests that AMP may strengthen brain connectivity in reward processing, attention, and emotion regulation networks.

Parsing the Neural Mechanisms of Short-Term and Long-Term Associations in the Flanker Tasks: An ERP Analysis

The neural mechanisms of cognitive conflicts within various flanker tasks are still unclear, which may be mixed with different effects of short-term associations and long-term associations. We applied a perceptual (color) flanker task and a symbolic (arrow) flanker task to 25 healthy young adults, while the event-related potentials (ERP) and behavioral performance were recorded. The former contains stimulus-stimulus conflict (SSC) of short-term memory (STM) associations, and the latter contains stimulus-response conflict (SRC) of long-term memory (LTM) associations. Both flanker tasks included congruent and incongruent conditions. The reaction time demonstrated the stimulus-response conflict effect in the arrow flanker task without the stimulus-stimulus conflict effect in the color flanker task. The ERP results showed SSC enhanced the frontocentral N2b without behavioral effects. SRC increased the frontocentral P2 but decreased the centroparietal P3b with prolonged reaction time. In the comparison between both tasks, the color flanker task elicited both the centroparietal N2b/N300 and the frontocentral N400, and the arrow flanker task increased the occipital N1. Our findings provide new evidence that different neural mechanisms underlie conflict effects based on different types of memory associations.

Theta activity from frontopolar cortex, mid-cingulate cortex and anterior cingulate cortex shows different roles in cognitive planning performance

Cognitive planning, the ability to develop a sequenced plan to achieve a goal, plays a crucial role in human goal-directed behavior. However, the specific role of frontal structures in planning is unclear. We used a novel and ecological task, that allowed us to separate the planning period from the execution period. The spatio-temporal dynamics of EEG recordings showed that planning induced a progressive and sustained increase of frontal-midline theta activity (FMθ) over time. Source analyses indicated that this activity was generated within the prefrontal cortex. Theta activity from the right mid-Cingulate Cortex (MCC) and the left Anterior Cingulate Cortex (ACC) were correlated with an increase in the time needed for elaborating plans. On the other hand, left Frontopolar cortex (FP) theta activity exhibited a negative correlation with the time required for executing a plan. Since reaction times of planning execution correlated with correct responses, left FP theta activity might be associated with efficiency and accuracy in making a plan. Associations between theta activity from the right MCC and the left ACC with reaction times of the planning period may reflect high cognitive demand of the task, due to the engagement of attentional control and conflict monitoring implementation. In turn, the specific association between left FP theta activity and planning performance may reflect the participation of this brain region in successfully self-generated plans.

Eriksen's two-phase model of spatial selective attention: Physiological evidence of trial-mixing-dependent response inhibition

The early work of Charles W. Eriksen and colleagues provided us with both the flanker task and the concepts of response competition and continuous flow. The model of the flanker task that Eriksen and colleagues developed also includes the idea that processing occurs in two phases and the specific claim that pro-active response inhibition is employed to prevent errors under certain conditions. We first replicated and extended the behavioral evidence that motivated this specific claim and then tested it using a variety of physiological measures. We verified the prediction of Eriksen's Two-Phase Model of Spatial Selective Attention using the lateralized readiness potential and contingent negative variation. We also clarified a detail of the model using electromyographic activity and response force. We note that this contribution of Charles W. Eriksen has not received the attention that it deserves and that several recent models might need to be revised in light of Eriksen's work.

Abnormal Fractional Amplitude of Low-Frequency Fluctuation Changes in Patients with Monocular Blindness: A Functional Magnetic Resonance Imaging (MRI) Study

BACKGROUND We used fractional amplitude of low-frequency fluctuation (fALFF) technology to investigate spontaneous cerebral activity in patients with monocular blindness (MB) and in healthy controls (HCs). MATERIAL AND METHODS Thirty MB patient and 15 HCs were included in this study. All subjects were scanned by resting-state functional magnetic resonance imaging (rs-fMRI). The independent sample t test and chi-squared test were applied to analyze demographics of MB patients and HCs. The 2-sample t test and receiver operating characteristic (ROC) curves were applied to identify the difference in average fALFF values between MB patients and HCs. Pearson's correlation analysis was applied to explore the relationship between the average fALFF values of brain areas and clinical behavior in the MB group. RESULTS MB patients had lower fALFF values in the left anterior cingulate and higher fALFF values in the left precuneus and right and left inferior parietal lobes than in HCs. Moreover, the mean fALFF values of MB patients in the left anterior cingulate had negative correlations with the anxiety scale score (r=-0.825, P<0.001) and the depression scale score (r=-0.871, P<0.001). CONCLUSIONS Our study found that MB patients had abnormal spontaneous activities in the visual and vision-related regions. The finding of abnormal neuronal activity helps to reveal the underlying neuropathologic mechanisms of vision loss.

Prefrontal cortical activation during working memory task anticipation contributes to discrimination between bipolar and unipolar depression

Distinguishing bipolar disorder (BD) from major depressive disorder (MDD) is clinically challenging, especially during depressive episodes. While both groups are characterized by aberrant working memory and anticipatory processing, the role of these processes in discriminating BD from MDD remains unexplored. In this study, we examine how brain activation corresponding to anticipation of and performance on easy vs. difficult working memory tasks with emotional stimuli contributes to discrimination among BD, MDD, and healthy controls (HC). Depressed individuals with BD (n = 18), MDD (n = 23), and HC (n = 23) were scanned while performing a working memory task in which they had to first anticipate performance on 1-back (easy) or 2-back (difficult) tasks with happy, fearful, or neutral faces, and then, perform the task. Anticipation-related and task-related brain activation was measured in the whole brain using functional magnetic resonance imagining. We used an elastic-net regression for variable selection, and a random forest classifier for BD vs. MDD classification. The former selected the activation differences (1-back minus 2-back) in the lateral and medial prefrontal cortices (PFC) during task anticipation and performance on the working memory tasks with fearful and neutral faces as variables relevant for BD vs. MDD classification. BD vs. MDD were classified with 70.7% accuracy (p < 0.01) based on the neuroimaging measures alone, with 80.5% accuracy (p = 0.001) based on clinical measures alone, and with 85.4% accuracy (p < 0.001) based on clinical and neuroimaging measures together. These findings suggest that PFC activation during working memory task anticipation and performance may be an important biological marker distinguishing BD from MDD.

Association of degree of loss aversion and grey matter volume in superior frontal gyrus by voxel-based morphometry

Loss-aversion behaviors reflect individuals' personal preference bias when they meet uncertainties and measure the potential gains and losses of the uncertain situations before making a decision. Such behaviors are common and well documented in daily life; one example is irrational financial investments. The exact neural mechanisms for these loss-aversion behaviors have been widely discussed. In this study, we explored the neural mechanisms of loss-aversion behaviors by using voxel-based morphometry of brain regions based on two datasets. In the behavioral analysis, the degree of individual behavioral loss aversion was measured. Voxel-based morphometry analysis revealed positive correlations between the degree of individual behavioral loss aversion and grey matter volume in the superior frontal gyrus, which may be crucial neural structures for individual loss-aversion behaviors.

APOE-ε4 risk variant for Alzheimer's disease modifies the association between cognitive performance and cerebral morphology in healthy middle-aged individuals

The APOE-ε4 genotype is the highest genetic risk factor for Alzheimer's disease (AD). In cognitively unimpaired individuals, it has been related to altered brain morphology, function and earlier amyloid beta accumulation. However, its impact on cognitive performance is less evident. Here, we examine the impact of APOE-ε4 allele load in modulating the association between cognitive functioning and brain morphology in middle-aged healthy individuals. A high-resolution structural MRI scan was acquired and episodic memory (EM) as well as executive functions (EFs) were assessed in a sample of 527 middle-aged unimpaired individuals hosting a substantial representation of ε4-homozygous (N = 64). We adopted a voxel-wise unbiased method to assess whether the number of APOE-ε4 alleles significantly modified the associations between gray matter volumes (GMv) and performance in both cognitive domains. Even though the APOE-ε4 allele load did not exert a direct impact on any cognitive measures, it reversed the relationships between GMv and cognitive performance in a highly symmetrical topological pattern. For EM, interactions mapped onto the inferior temporal gyrus and the dorsal anterior cingulate cortex. Regarding EFs, significant interactions were observed for processing speed, working memory, and visuospatial attention in distinct brain regions. These results suggest that APOE-ε4 carriers display a structure-function association corresponding to an older age than their chronological one. Our findings additionally indicate that APOE-ε4 carriers may rely on the integrity of multiple compensatory brain systems in order to preserve their cognitive abilities, possibly due to an incipient neurodegeneration. Overall this study provides novel insights on the mechanisms through which APOE-ε4 posits an increased AD risk.

Flanker paradigm contains conflict and distraction factors with distinct neural mechanisms: an ERP analysis in a 2-1 mapping task

Behavioral studies using the flanker 2-1 mapping task suggest that both stimulus and response conflicts contribute to flanker conflict effect. However, both are intertwined with distraction effect. Their underlying neural mechanisms remain unclear. We applied a perceptual flanker 2-1 mapping task to 24 healthy young adults, while the event-related potentials were recorded. The task included stimulus-incongruent (SI), response-incongruent (RI), congruent (CO) and neutral (NE) stimuli. Our reaction time data demonstrated conflict effect, distraction effect and their interaction. Furthermore, the conflict factor successively enhanced the frontal P2 (160-240 ms), the posterior N2pc (200-240 ms), the fronto-central and the right frontal N2b (240-420 ms), and the posterior N2c (320-420 ms). Only the frontal P2 was larger for RI than SI. The distraction factor increased the right N2pc and reduced the left parietal P3b (460-480 ms). Overall, our findings suggested that the flanker conflict involved an early attentional processing of task-relevant and distractive information, and a later processing of conflict evaluation and response inhibition.

Altruistic and self-serving goals modulate behavioral and neural responses in deception

People tell lies not only for their own self-interests but sometimes also to help others. Little is known about the ways in which different types of goals modulate behaviors and neural responses in deception. The present study investigated the neural processes associated with spontaneous deception that occurs with altruistic reasons (i.e. the money would be donated to charity), self-serving reasons (i.e. the participant receives all of the money) and mixed goals (i.e. the money would be equally split between the participant and the charity). Altruistic motivation for deception reduced the intensity of moral conflict and the subsequent mental cost of resolving this conflict, reflected by a smaller N2–P3 effect in the purely altruistic condition. When making decisions about whether to lie, self-interest was a stronger motivator than others’ interests, and the participants tended to lie more for themselves than for others. When the lie could be mutually beneficial for both of the self and others, the participants tended to lie even when they knew that they could be easily caught, but they actually lied for their own self-interest rather than for altruistic reasons. These findings shed light on the neural basis of ‘good lies’ and decision-making in mutually beneficial situations.

Behavioral facilitation and increased brain responses from a high interference working memory context

Many real-life situations require flexible behavior in changing environments. Evidence suggests that anticipation of conflict or task difficulty results in behavioral and neural allocation of task-relevant resources. Here we used a high- and low-interference version of an item-recognition task to examine the neurobehavioral underpinnings of context-sensitive adjustment in working memory (WM). We hypothesized that task environments that included high-interference trials would require participants to allocate neurocognitive resources to adjust to the more demanding task context. The results of two independent behavioral experiments showed enhanced WM performance in the high-interference context, which indicated that a high-interference context improves performance on non-interference trials. A third behavioral experiment showed that when WM load was increased, this effect was no longer significant. Neuroimaging results further showed greater engagement of inferior frontal gyrus, striatum, parietal cortex, hippocampus, and midbrain in participants performing the task in the high- than in the low-interference context. This effect could arise from an active or dormant mode of anticipation that seems to engage fronto-striatal and midbrain regions to flexibly adjust resources to task demands. Our results extend the model of conflict adaptation beyond trial-to-trial adjustments by showing that a high interference context affects both behavioral and biological aspects of cognition.

Theta Activity in the Left Dorsal Premotor Cortex During Action Re-Evaluation and Motor Reprogramming

The ability to rapidly adjust our actions to changes in the environment is a key function of human motor control. Previous work implicated the dorsal premotor cortex (dPMC) in the up-dating of action plans based on environmental cues. Here we used electroencephalography (EEG) to identify neural signatures of up-dating cue-action relationships in the dPMC and connected frontoparietal areas. Ten healthy subjects performed a pre-cued alternate choice task. Simple geometric shapes cued button presses with the right or left index finger. The shapes of the pre-cue and go-cue differed in two third of trials. In these incongruent trials, the go-cue prompted a re-evaluation of the pre-cued action plan, slowing response time relative to trials with identical cues. This re-evaluation selectively increased theta band activity without modifying activity in alpha and beta band. Source-based analysis revealed a widespread theta increase in dorsal and mesial frontoparietal areas, including dPMC, supplementary motor area (SMA), primary motor and posterior parietal cortices (PPC). Theta activity scaled positively with response slowing and increased more strongly when the pre-cue was invalid and required subjects to select the alternate response. Together, the results indicate that theta activity in dPMC and connected frontoparietal areas is involved in the re-adjustment of cue-induced action tendencies.

Hearing and orally mimicking different acoustic-semantic categories of natural sound engage distinct left hemisphere cortical regions

Oral mimicry is thought to represent an essential process for the neurodevelopment of spoken language systems in infants, the evolution of language in hominins, and a process that could possibly aid recovery in stroke patients. Using functional magnetic resonance imaging (fMRI), we previously reported a divergence of auditory cortical pathways mediating perception of specific categories of natural sounds. However, it remained unclear if or how this fundamental sensory organization by the brain might relate to motor output, such as sound mimicry. Here, using fMRI, we revealed a dissociation of activated brain regions preferential for hearing with the intent to imitate and the oral mimicry of animal action sounds versus animal vocalizations as distinct acoustic-semantic categories. This functional dissociation may reflect components of a rudimentary cortical architecture that links systems for processing acoustic-semantic universals of natural sound with motor-related systems mediating oral mimicry at a category level. The observation of different brain regions involved in different aspects of oral mimicry may inform targeted therapies for rehabilitation of functional abilities after stroke.

Functional and anatomical connectivity-based parcellation of human cingulate cortex

INTRODUCTION

Human cingulate cortex (CC) has been implicated in many functions, which is highly suggestive of the existence of functional subregions.

METHODS

In this study, we used resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) to parcellate the human cingulate cortex (CC) based on resting-state functional connectivity (rsFC) patterns and anatomical connectivity (AC) patterns, to analyze the rsFC patterns and the AC patterns of different subregions, and to recognize whether the parcellation results obtained by the two different methods were consistent.

RESULTS

The CC was divided into six functional subregions, including the anterior cingulate cortex, dorsal anterior midcingulate cortex, ventral anterior midcingulate cortex, posterior midcingulate cortex, dorsal posterior cingulate cortex, and ventral posterior cingulate cortex. The CC was also divided into ten anatomical subregions, termed Subregion 1 (S1) to Subregion 10 (S10). Each subregion showed specific connectivity patterns, although the functional subregions and the anatomical subregions were internally consistent.

CONCLUSIONS

Using different model MRI images, we established a parcellation scheme, which is internally consistent for the human CC, which may provide an in vivo guide for subregion-level studies and improve our understanding of this brain area at subregional levels.

Verbal and Nonverbal Anticipatory Mechanisms in Bilinguals

Empirical evidence collected so far has revealed that the bilingual advantage cannot be reduced to a single component of the executive functioning, and point to the need to understand the effects of bilingual experience on cognition as influencing a wider family of mental processes, including, but not limited to, cognitive control. The present study aims to explore a relatively underinvestigated domain of bilingual cognitive processes, namely anticipation, through a series of different paradigms tapping proactive and reactive mechanisms at different levels of cognitive complexity and linguistic components. The sample included 25 adult bilinguals ([Formula: see text] years) and 25 monolinguals ([Formula: see text] years) matched for age, gender, and non-verbal IQ. Participants were administered two experimental tasks: Attentional Network Task (ANT), and auditory picture-word identification task. Compared to monolinguals, bilinguals showed overall faster reaction times and reduced conflict effect on both the ANT and the picture-word identification task. In addition, associations between performances in the nonverbal and the verbal tasks support the role of the nonverbal monitoring component on verbal anticipation. Results are discussed in light of a dynamic interaction between proactive and reactive mechanisms of cognitive control.

Differential Resting-State Connectivity Patterns of the Right Anterior and Posterior Dorsolateral Prefrontal Cortices (DLPFC) in Schizophrenia

In schizophrenia (SCZ), dysfunction of the dorsolateral prefrontal cortex (DLPFC) has been linked to the deficits in executive functions and attention. It has been suggested that, instead of considering the right DLPFC as a cohesive functional entity, it can be divided into two parts (anterior and posterior) based on its whole-brain connectivity patterns. Given these two subregions' differential association with cognitive processes, we investigated the functional connectivity (FC) profile of both subregions through resting-state data to determine whether they are differentially affected in SCZ. Resting-state magnetic resonance imaging (MRI) scans were obtained from 120 patients and 172 healthy controls (HC) at 6 different MRI sites. The results showed differential FC patterns for the anterior and posterior parts of the right executive control-related DLPFC in SCZ with the parietal, the temporal and the cerebellar regions, along with a convergent reduction of connectivity with the striatum and the occipital cortex. An increased psychopathology level was linked to a higher difference in posterior vs. anterior FC for the left IFG/anterior insula, regions involved in higher-order cognitive processes. In sum, the current analysis demonstrated that even between two neighboring clusters connectivity could be differentially disrupted in SCZ. Lacking the necessary anatomical specificity, such notions may in fact be detrimental to a proper understanding of SCZ pathophysiology.

Neural Mechanisms for Adaptive Learned Avoidance of Mental Effort

Humans tend to avoid mental effort. Previous studies have demonstrated this tendency using various demand-selection tasks; participants generally avoid options associated with higher cognitive demand. However, it remains unclear whether humans avoid mental effort adaptively in uncertain and nonstationary environments. If so, it also remains unclear what neural mechanisms underlie such learned avoidance and whether they remain the same regardless of cognitive-demand types. We addressed these issues by developing novel demand-selection tasks where associations between choice options and cognitive-demand levels change over time, with two variations using mental arithmetic and spatial reasoning problems (males/females: 29:4 and 18:2). Most participants showed avoidance, and their choices depended on the demand experienced on multiple preceding trials. We assumed that participants updated the expected cost of mental effort through experience, and fitted their choices by reinforcement learning models, comparing several possibilities. Model-based fMRI analyses revealed that activity in the dorsomedial and lateral frontal cortices was positively correlated with the trial-by-trial expected cost for the chosen option commonly across the different types of cognitive demand. Analyses also revealed a trend of negative correlation in the ventromedial prefrontal cortex. We further identified correlates of cost-prediction error at time of problem presentation or answering the problem, the latter of which partially overlapped with or were proximal to the correlates of expected cost at time of choice cue in the dorsomedial frontal cortex. These results suggest that humans adaptively learn to avoid mental effort, having neural mechanisms to represent expected cost and cost-prediction error, and the same mechanisms operate for various types of cognitive demand.SIGNIFICANCE STATEMENT In daily life, humans encounter various cognitive demands and tend to avoid high-demand options. However, it remains unclear whether humans avoid mental effort adaptively under dynamically changing environments. If so, it also remains unclear what the underlying neural mechanisms are and whether they operate regardless of cognitive-demand types. To address these issues, we developed novel tasks where participants could learn to avoid high-demand options under uncertain and nonstationary environments. Through model-based fMRI analyses, we found regions whose activity was correlated with the expected mental effort cost, or cost-prediction error, regardless of demand type. These regions overlap, or are adjacent with each other, in the dorsomedial frontal cortex. This finding helps clarify the mechanisms for cognitive-demand avoidance, and provides empirical building blocks for the emerging computational theory of mental effort.

Distinct Roles for the Anterior Cingulate and Dorsolateral Prefrontal Cortices During Conflict Between Abstract Rules

Distinct patterns of activity within the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (dlPFC) reported in neuroimaging studies during tasks involving conflict between competing responses have often been cited as evidence for their key contributions to conflict-monitoring and behavioral adaptation, respectively. However, supporting evidence from neuropsychological patients has been scarce and contradictory. We administered a well-studied analog of the Wisconsin Card Sorting Test, designed to elicit conflict between 2 abstract rules, to a cohort of 6 patients with damage to ACC or dlPFC. Patients who had sustained more significant damage to the ACC were not impaired either on a measure of "conflict cost" nor on measures of "conflict-induced behavioral adaptation." In contrast, damage to dlPFC did not affect the conflict cost measure but abolished the patients' ability to adapt their behavior following exposure to conflict, compared with controls. This pattern of results complements the findings from nonhuman primates with more circumscribed lesions to ACC or dlPFC on the same task and provides converging evidence that ACC is not necessary for performance when conflict is elicited between 2 abstract rules, whereas dlPFC plays a fundamental role in behavioral adaptation.

The cortisol awakening response and anterior cingulate cortex function in maltreated depressed versus non-maltreated depressed youth

Symptomatology of depression among children who have (vs. have not) experienced maltreatment is greater in severity, more resistant to conventional treatment, and associated with elevated risk for suicide. Recent evidence implicates perturbations in stress regulatory systems and heightened negative self-appraisals as factors that increase the severity of psychopathology experienced by depressed maltreated (vs. non-maltreated) youth. Likely explanatory mechanisms for these differences are disturbances in the function of the hypothalamic-pituitary axis (HPA) and persistent negative self-referential biases supported by prefrontal cortex function including the dorsal anterior cingulate cortex (dACC). The cortisol awakening response (CAR) and dACC activity during a self-appraisal task were assessed in maltreated and non-maltreated depressed youth. Hierarchical linear models were employed to model the CAR. Maltreatment group, dACC activity during positive and negative self-appraisals as well as other key predictors, were included in the models. Post hoc analyses explored explanations for significant differences. Results indicated that maltreated depressed youth exhibited a higher CAR compared to non-maltreated youth. At low levels of dACC activity during processing of negative self-descriptors maltreated and non-maltreated depressed youth's CAR did not differ. However, at elevated levels of dACC activity during processing of negative self-descriptors maltreated depressed youth exhibited significantly higher CAR compared to non-maltreated depressed youth.

A Biologically Plausible Action Selection System for Cognitive Architectures: Implications of Basal Ganglia Anatomy for Learning and Decision-Making Models

Several attempts have been made previously to provide a biological grounding for cognitive architectures by relating their components to the computations of specific brain circuits. Often, the architecture's action selection system is identified with the basal ganglia. However, this identification overlooks one of the most important features of the basal ganglia-the existence of a direct and an indirect pathway that compete against each other. This characteristic has important consequences in decision-making tasks, which are brought to light by Parkinson's disease as well as genetic differences in dopamine receptors. This paper shows that a standard model of action selection in a cognitive architecture (ACT-R) cannot replicate any of these findings, details an alternative solution that reconciles action selection in the architecture with the physiology of the basal ganglia, and extends the domain of application of cognitive architectures. The implication of this solution for other architectures and existing models are discussed.

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

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

Basal ganglia impairments in autism spectrum disorder are related to abnormal signal gating to prefrontal cortex

Research on the biological basis of autism spectrum disorder has yielded a list of brain abnormalities that are arguably as diverse as the set of behavioral symptoms that characterize the disorder. Among these are patterns of abnormal cortical connectivity and abnormal basal ganglia development. In attempts to integrate the existing literature, the current paper tests the hypothesis that impairments in the basal ganglia's function to flexibly select and route task-relevant neural signals to the prefrontal cortex underpins patterns of abnormal synchronization between the prefrontal cortex and other cortical processing centers observed in individuals with autism spectrum disorder (ASD). We tested this hypothesis using a Dynamic Causal Modeling analysis of neuroimaging data collected from 16 individuals with ASD (mean age=25.3 years; 6 female) and 17 age- and IQ-matched neurotypical controls (mean age=25.6, 6 female), who performed a Go/No-Go test of executive functioning. Consistent with the hypothesis tested, a random-effects Bayesian model selection procedure determined that a model of network connectivity in which basal ganglia activation modulated connectivity between the prefrontal cortex and other key cortical processing centers best fit the data of both neurotypicals and individuals with ASD. Follow-up analyses suggested that the largest group differences were observed for modulation of connectivity between prefrontal cortex and the sensory input region in the occipital lobe [t(31)=2.03, p=0.025]. Specifically, basal ganglia activation was associated with a small decrease in synchronization between the occipital region and prefrontal cortical regions in controls; however, in individuals with ASD, basal ganglia activation resulted in increased synchronization between the occipital region and the prefrontal cortex. We propose that this increased synchronization may reflect a failure in basal ganglia signal gating mechanisms, resulting in a non-selective copying of signals to prefrontal cortex. Such a failure to prioritize and filter signals to the prefrontal cortex could result in the pervasive impairments in cognitive flexibility and executive functioning that characterize autism spectrum disorder, and may offer a mechanistic explanation of some of the observed abnormalities in patterns of cortical synchronization in ASD.

Randomised prior feedback modulates neural signals of outcome monitoring

Substantial evidence indicates that decision outcomes are typically evaluated relative to expectations learned from relatively long sequences of previous outcomes. This mechanism is thought to play a key role in general learning and adaptation processes but relatively little is known about the determinants of outcome evaluation when the capacity to learn from series of prior events is difficult or impossible. To investigate this issue, we examined how the feedback-related negativity (FRN) is modulated by information briefly presented before outcome evaluation. The FRN is a brain potential time-locked to the delivery of decision feedback and it is widely thought to be sensitive to prior expectations. We conducted a multi-trial gambling task in which outcomes at each trial were fully randomised to minimise the capacity to learn from long sequences of prior outcomes. Event-related potentials for outcomes (Win/Loss) in the current trial (Outcome_t) were separated according to the type of outcomes that occurred in the preceding two trials (Outcome_t-1 and Outcome_t-2). We found that FRN voltage was more positive during the processing of win feedback when it was preceded by wins at Outcome_t-1 compared to win feedback preceded by losses at Outcome_t-1. However, no influence of preceding outcomes was found on FRN activity relative to the processing of loss feedback. We also found no effects of Outcome_t-2 on FRN amplitude relative to current feedback. Additional analyses indicated that this effect was largest for trials in which participants selected a decision different to the gamble chosen in the previous trial. These findings are inconsistent with models that solely relate the FRN to prediction error computation. Instead, our results suggest that if stable predictions about future events are weak or non-existent, then outcome processing can be determined by affective systems. More specifically, our results indicate that the FRN is likely to reflect the activity of positive affective systems in these contexts. Importantly, our findings indicate that a multifactorial explanation of the nature of the FRN is necessary and such an account must incorporate affective and motivational factors in outcome processing.

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FRN is sensitive to prior events but does this persist when learning is impossible?

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Four FRN theories were examined in a task with fully randomised feedback.

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Previous trial outcome modulated FRN during positive but not negative outcomes.

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Results consistent with a positive affective modulation interpretation of the FRN.

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FRN is determined by factors beyond prediction error (e.g. affective/motivational).

Functional Roles of Neural Preparatory Processes in a Cued Stroop Task Revealed by Linking Electrophysiology with Behavioral Performance

It is well established that cuing facilitates behavioral performance and that different aspects of instructional cues evoke specific neural preparatory processes in cued task-switching paradigms. To deduce the functional role of these neural preparatory processes the majority of studies vary aspects of the experimental paradigm and describe how these variations alter markers of neural preparatory processes. Although these studies provide important insights, they also have notable limitations, particularly in terms of understanding the causal or functional relationship of neural markers to cognitive and behavioral processes. In this study, we sought to address these limitations and uncover the functional roles of neural processes by examining how variability in the amplitude of neural preparatory processes predicts behavioral performance to subsequent stimuli. To achieve this objective 16 young adults were recruited to perform a cued Stroop task while their brain activity was measured using high-density electroencephalography. Four temporally overlapping but functionally and topographically distinct cue-triggered event related potentials (ERPs) were identified: 1) A left-frontotemporal negativity (250-700 ms) that was positively associated with word-reading performance; 2) a midline-frontal negativity (450-800 ms) that was positively associated with color-naming and incongruent performance; 3) a left-frontal negativity (450-800 ms) that was positively associated with switch trial performance; and 4) a centroparietal positivity (450-800 ms) that was positively associated with performance for almost all trial types. These results suggest that at least four dissociable cognitive processes are evoked by instructional cues in the present task, including: 1) domain-specific task facilitation; 2) switch-specific task-set reconfiguration; 3) preparation for response conflict; and 4) proactive attentional control. Examining the relationship between ERPs and behavioral performance provides a functional link between neural markers and the cognitive processes they index.

Flexible brain network reconfiguration supporting inhibitory control

The ability to inhibit distracting stimuli from interfering with goal-directed behavior is crucial for success in most spheres of life. Despite an abundance of studies examining regional brain activation, knowledge of the brain networks involved in inhibitory control remains quite limited. To address this critical gap, we applied graph theory tools to functional magnetic resonance imaging data collected while a large sample of adults (n = 101) performed a color-word Stroop task. Higher demand for inhibitory control was associated with restructuring of the global network into a configuration that was more optimized for specialized processing (functional segregation), more efficient at communicating the output of such processing across the network (functional integration), and more resilient to potential interruption (resilience). In addition, there were regional changes with right inferior frontal sulcus and right anterior insula occupying more central positions as network hubs, and dorsal anterior cingulate cortex becoming more tightly coupled with its regional subnetwork. Given the crucial role of inhibitory control in goal-directed behavior, present findings identifying functional network organization supporting inhibitory control have the potential to provide additional insights into how inhibitory control may break down in a wide variety of individuals with neurological or psychiatric difficulties.

Dorsal anterior cingulate cortex modulates supplementary motor area in coordinated unimanual motor behavior

Motor control is integral to all types of human behavior, and the dorsal Anterior Cingulate Cortex (dACC) is thought to play an important role in the brain network underlying motor control. Yet the role of the dACC in motor control is under-characterized. Here we aimed to characterize the dACC's role in adolescent brain network interactions during a simple motor control task involving visually coordinated unimanual finger movements. Network interactions were assessed using both undirected and directed functional connectivity analysis of functional Magnetic Resonance Imaging (fMRI) Blood-Oxygen-Level-Dependent (BOLD) signals, comparing the task with a rest condition. The relation between the dACC and Supplementary Motor Area (SMA) was compared to that between the dACC and Primary Motor Cortex (M1). The directed signal from dACC to SMA was significantly elevated during motor control in the task. By contrast, the directed signal from SMA to dACC, both directed signals between dACC and M1, and the undirected functional connections of dACC with SMA and M1, all did not differ between task and rest. Undirected coupling of dACC with both SMA and dACC, and only the dACC-to-SMA directed signal, were significantly greater for a proactive than a reactive task condition, suggesting that dACC plays a role in motor control by maintaining stimulus timing expectancy. Overall, these results suggest that the dACC selectively modulates the SMA during visually coordinated unimanual behavior in adolescence. The role of the dACC as an important brain area for the mediation of task-related motor control may be in place in adolescence, continuing into adulthood. The task and analytic approach described here should be extended to the study of healthy adults to examine network profiles of the dACC during basic motor behavior.

Differentiating SCT and inattentive symptoms in ADHD using fMRI measures of cognitive control

Attention Deficit/Hyperactivity Disorder (ADHD) is associated with different impairment profiles in the symptom domains of hyperactivity/impulsivity and/or inattention. An additional symptom domain of sluggish cognitive tempo (SCT) has also been proposed. Although there is a degree of correlation between the SCT symptom domain and inattention, it has been proposed as a distinct disorder independent of ADHD. The objective of this study was to examine the neural substrates of cue-related preparatory processes associated with SCT symptoms versus inattentive symptoms in a group of adolescents with ADHD. We also compared cue-related effects in the entire ADHD group compared with a group of typically developing (TD) peers. A modified cued flanker paradigm and fMRI examined brain activity associated with attention preparation and motor response preparation. Between group contrasts between the ADHD and TD group revealed significant hypoactivity in the ADHD group during general attention preparation in the supplementary motor area (SMA) and in the right superior parietal lobe (SPL) during response preparation. In the ADHD group, greater numbers of SCT symptoms were associated with hypoactivity in the left SPL to cues in general whereas greater numbers of inattentive symptoms were associated with greater activity in the SMA to cues that provided no information and less activity in the thalamus during response preparation. Hypoactivity in the SPL with increasing SCT symptoms may be associated with impaired reorienting or shifting of attention. Altered activity in the SMA and thalamus with increasing inattention may be associated with a general problem with response preparation, which may also reflect inefficient processing of the response preparation cue. Our results support a degree of differentiation between SCT and inattentive symptom profiles within adolescents with ADHD.

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We examine cognitive control activity in ADHD SCT versus inattentive symptomatology.

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An increase in SCT symptoms was associated with impaired attention orienting.

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More inattentive symptoms were associated with impaired response preparation.

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SCT activity differed from inattentive activity in adolescents with ADHD.