Supramodal Mechanisms of the Cognitive Control Network in Uncertainty Processing

Early life stress, literacy and dyslexia: an evolutionary perspective

Stress and learning co-evolved in parallel, with their interdependence critical to the survival of the species. Even today, the regulation of moderate levels of stress by the central autonomic network (CAN), especially during pre- and post-natal periods, facilitates biological adaptability and is an essential precursor for the cognitive requisites of learning to read. Reading is a remarkable evolutionary achievement of the human brain, mysteriously unusual, because it is not pre-wired with a genetic address to facilitate its acquisition. There is no gene for reading. The review suggests that reading co-opts a brain circuit centered in the left hemisphere ventral occipital cortex that evolved as a domain-general visual processor. Its adoption by reading depends on the CAN's coordination of the learning and emotional requirements of learning to read at the metabolic, cellular, synaptic, and network levels. By stabilizing a child's self-control and modulating the attention network's inhibitory controls over the reading circuit, the CAN plays a key role in school readiness and learning to read. In addition, the review revealed two beneficial CAN evolutionary adjustments to early-life stress "overloads" that come with incidental costs of school under-performance and dyslexia. A short-term adaptation involving methylation of the FKBP5 and NR3C1 genes is a liability for academic achievement in primary school. The adaptation leading to dyslexia induces alterations in BDNF trafficking, promoting long-term adaptive fitness by protecting against excessive glucocorticoid toxicity but risks reading difficulties by disruptive signaling from the CAN to the attention networks and the reading circuit.

Dorsolateral prefrontal activity supports a cognitive space organization of cognitive control

Cognitive control resolves conflicts between task-relevant and -irrelevant information to enable goal-directed behavior. As conflicts can arise from different sources (e.g., sensory input, internal representations), how a limited set of cognitive control processes can effectively address diverse conflicts remains a major challenge. Based on the cognitive space theory, different conflicts can be parameterized and represented as distinct points in a (low-dimensional) cognitive space, which can then be resolved by a limited set of cognitive control processes working along the dimensions. It leads to a hypothesis that conflicts similar in their sources are also represented similarly in the cognitive space. We designed a task with five types of conflicts that could be conceptually parameterized. Both human performance and fMRI activity patterns in the right dorsolateral prefrontal cortex support that different types of conflicts are organized based on their similarity, thus suggesting cognitive space as a principle for representing conflicts.

The impact of bilingualism in within-language conflict resolution: an ERP study

We compared Spanish (L1)-English (L2) bilinguals and Spanish monolinguals in a semantic judgment relationship task in L1 that produced within-language conflict due to the coactivation of the two meanings of a Spanish homophone (e.g., "hola" and "ola" meaning "hello" and "a wave" in English). In this task, participants indicated if pairs of words were related or not ("agua-hola," "water-hello"). Conflict arose because a word ("agua," "water") not related to the orthographic form of a homophone ("hola," "hello") was related to the alternative orthographic form ("ola," "wave"). Compared to a control condition with unrelated word pairs ("peluche-hola," "teddy-hello"), the behavioral results revealed greater behavioral interference in monolinguals compared to bilinguals. In addition, electrophysiological results revealed N400 differences between monolinguals and bilinguals. These results are discussed around the impact of bilingualism on conflict resolution.

Resource sharing in cognitive control: behavioral evidence and neural substrates

Cognitive control is a capacity limited function responsible for the resolution of conflict among competing cognitive processes. However, it remains elusive whether cognitive control handles multiple concurrent requests through a single bottleneck or a resource sharing mechanism. In this functional magnetic resonance imaging study, we examined the effect of dual flanker conflict processing on behavioral performance and on activation in regions of the cognitive control network (CCN). In each trial, participants completed two flanker conflict tasks (T1 and T2) sequentially, with the stimulus onset asynchrony (SOA) varied as short (100 ms) and long (1000 ms). We found that there was a significant conflict effect (indexed by the difference between incongruent and congruent flanker conditions) in reaction time (RT), a significant interaction between SOA and T1 incongruency on RT for T2 with an additive effect. Importantly, there was a small but significant SOA effect on T1 with a prolonged RT under the short SOA compared to the long SOA. Increased activation in the CCN was associated with the conflict processing and the main effect of SOA. The anterior cingulate cortex and anterior insular cortex showed a significant interaction effect between SOA and T1 incongruency in activation in parallel with the behavioral results. The behavioral and brain activation patterns are in support of a central resource sharing model, in which the core resources for cognitive control are shared when multiple simultaneous conflicting processes are required.

EEG Dynamics of Error Processing and Associated Behavioral Adjustments in Preschool Children

Preschool children show neural responses and make behavioral adjustments immediately following an error. However, there is a lack of evidence regarding how neural responses to error predict subsequent behavioral adjustments during childhood. The aim of our study was to explore the neural dynamics of error processing and associated behavioral adjustments in preschool children from unsatisfied basic needs (UBN) homes. Using EEG recordings during a go/no-go task, we examined within-subject associations between the error-related negativity (ERN), frontal theta power, post-error slowing, and post-error accuracy. Post-error accuracy increased linearly with post-error slowing, and there was no association between the neural activity of error processing and post-error accuracy. However, during successful error recovery, the frontal theta power, but not the ERN amplitude, was associated positively with post-error slowing. These findings indicated that preschool children from UBN homes adjusted their behavior following an error in an adaptive form and that the error-related theta activity may be associated with the adaptive forms of post-error behavior. Furthermore, our data support the adaptive theory of post-error slowing and point to some degree of separation between the neural mechanisms represented by the ERN and theta.

Active Inference, Epistemic Value, and Uncertainty in Conceptual Disorganization in First-Episode Schizophrenia

BACKGROUND AND HYPOTHESIS

Active inference has become an influential concept in psychopathology. We apply active inference to investigate conceptual disorganization in first-episode schizophrenia. We conceptualize speech production as a decision-making process affected by the latent "conceptual organization"-as a special case of uncertainty about the causes of sensory information. Uncertainty is both minimized via speech production-in which function words index conceptual organization in terms of analytic thinking-and tracked by a domain-general salience network. We hypothesize that analytic thinking depends on conceptual organization. Therefore, conceptual disorganization in schizophrenia would be both indexed by low conceptual organization and reflected in the effective connectivity within the salience network.

STUDY DESIGN

With 1-minute speech samples from a picture description task and resting state fMRI from 30 patients and 30 healthy subjects, we employed dynamic causal and probabilistic graphical models to investigate if the effective connectivity of the salience network underwrites conceptual organization.

STUDY RESULTS

Low analytic thinking scores index low conceptual organization which affects diagnostic status. The influence of the anterior insula on the anterior cingulate cortex and the self-inhibition within the anterior cingulate cortex are elevated given low conceptual organization (ie, conceptual disorganization).

CONCLUSIONS

Conceptual organization, a construct that explains formal thought disorder, can be modeled in an active inference framework and studied in relation to putative neural substrates of disrupted language in schizophrenia. This provides a critical advance to move away from rating-scale scores to deeper constructs in the pursuit of the pathophysiology of formal thought disorder.

The cost of attentional reorienting on conscious visual perception: an MEG study

How do attentional networks influence conscious perception? To answer this question, we used magnetoencephalography in human participants and assessed the effects of spatially nonpredictive or predictive supra-threshold peripheral cues on the conscious perception of near-threshold Gabors. Three main results emerged. (i) As compared with invalid cues, both nonpredictive and predictive valid cues increased conscious detection. Yet, only predictive cues shifted the response criterion toward a more liberal decision (i.e. willingness to report the presence of a target under conditions of greater perceptual uncertainty) and affected target contrast leading to 50% detections. (ii) Conscious perception following valid predictive cues was associated to enhanced activity in frontoparietal networks. These responses were lateralized to the left hemisphere during attentional orienting and to the right hemisphere during target processing. The involvement of frontoparietal networks occurred earlier in valid than in invalid trials, a possible neural marker of the cost of re-orienting attention. (iii) When detected targets were preceded by invalid predictive cues, and thus reorienting to the target was required, neural responses occurred in left hemisphere temporo-occipital regions during attentional orienting, and in right hemisphere anterior insular and temporo-occipital regions during target processing. These results confirm and specify the role of frontoparietal networks in modulating conscious processing and detail how invalid orienting of spatial attention disrupts conscious processing.

Interaction within and between cortical networks subserving multisensory learning and its reorganization due to musical expertise

Recent advancements in the field of network science allow us to quantify inter-network information exchange and model the interaction within and between task-defined states of large-scale networks. Here, we modeled the inter- and intra- network interactions related to multisensory statistical learning. To this aim, we implemented a multifeatured statistical learning paradigm and measured evoked magnetoencephalographic responses to estimate task-defined state of functional connectivity based on cortical phase interaction. Each network state represented the whole-brain network processing modality-specific (auditory, visual and audiovisual) statistical learning irregularities embedded within a multisensory stimulation stream. The way by which domain-specific expertise re-organizes the interaction between the networks was investigated by a comparison of musicians and non-musicians. Between the modality-specific network states, the estimated connectivity quantified the characteristics of a supramodal mechanism supporting the identification of statistical irregularities that are compartmentalized and applied in the identification of uni-modal irregularities embedded within multisensory stimuli. Expertise-related re-organization was expressed by an increase of intra- and a decrease of inter-network connectivity, showing increased compartmentalization.

The Neural Mechanisms of Cognitive Control in the Category Induction Task

According to the conflict monitoring hypothesis, conflict monitoring and inhibitory control in cognitive control mainly cause activity in the anterior cingulate cortex (ACC) and control-related prefrontal cortex (PFC) in many cognitive tasks. However, the role of brain regions in the default mode network (DMN) in cognitive control during category induction tasks is unclear. To test the role of the ACC, PFC, and subregions of the DMN elicited by cognitive control during category induction, a modified category induction task was performed using simultaneous fMRI scanning. The results showed that the left middle frontal gyrus (BA9) and bilateral dorsal ACC/medial frontal gyrus (BA8/32) were sensitive to whether conflict information (with/without) appears, but not to the level of conflict. In addition, the bilateral ventral ACC (BA32), especially the right vACC, a part of the DMN, showed significant deactivation with an increase in cognitive effort depending on working memory. These findings not only offer further evidence for the important role of the dorsolateral PFC and dorsal ACC in cognitive control during categorization but also support the functional distinction of the dorsal/ventral ACC in the category induction task.

Visual mental imagery: Inside the mind's eyes

What are mental images needed for? A variety of everyday situations calls for us to plan ahead; one of the clever ways our mind prepares and strategizes our next move is through mental simulation. A powerful tool in running these simulations is visual mental imagery, which can be conceived as a way to activate and maintain an internal representation of the to-be-imagined object, giving rise to predictions. Therefore, under normal conditions imagination is primarily an endogenous process, and only more rarely can mental images be activated exogenously, for example, by means of intracerebral stimulation. A large debate is still ongoing regarding the neural substrates supporting mental imagery, with the neuropsychological and neuroimaging literature agreeing in some cases, but not others. This chapter reviews the neuroscientific literature on mental imagery, and attempts to reappraise the neuropsychological and neuroimaging evidence by drawing a model of mental imagery informed by both structural and functional brain data. Overall, the role of regions in the ventral temporal cortex, especially of the left hemisphere, stands out unequivocally as a key substrate in mental imagery.

Distinct neural-behavioral correspondence within face processing and attention networks for the composite face effect

The composite face effect (CFE) is recognized as a hallmark for holistic face processing, but our knowledge remains sparse about its cognitive and neural loci. Using functional magnetic resonance imaging with independent localizer and complete composite face task, we here investigated its neural-behavioral correspondence within face processing and attention networks. Complementing classical comparisons, we adopted a dimensional reduction approach to explore the core cognitive constructs of the behavioral CFE measurement. Our univariate analyses found an alignment effect in regions associated with both the extended face processing network and attention networks. Further representational similarity analyses based on the Euclidian distances among all experimental conditions were used to identify cortical regions with reliable neural-behavioral correspondences. Multidimensional scaling and hierarchical clustering analyses for neural-behavioral correspondence data revealed two principal components underlying the behavioral CFE effect, which fit best to the neural responses in the bilateral insula and medial frontal gyrus. These findings highlight the distinct neurocognitive contributions of both face processing and attentional networks to the behavioral CFE outcome, which bridge the gaps between face recognition and attentional control models.

Midfrontal theta oscillations and conflict monitoring in children and adults

Conflict monitoring is central in cognitive control, as detection of conflict serves as a signal for the need to engage control. This study examined whether (1) midfrontal theta oscillations similarly support conflict monitoring in children and adults, and (2) performance monitoring difficulty influences conflict monitoring and resolution. Children (n = 25) and adults (n = 24) completed a flanker task with fair or rigged response feedback. Relative to adults, children showed a smaller congruency effect on midfrontal theta power, overall lower midfrontal theta power and coherence, and (unlike adults) no correlation between midfrontal theta power and N2 amplitude, suggesting that reduced neural communication efficiency contributes to less efficient conflict monitoring in children than adults. In both age groups, response feedback fairness affected response times and the P3, but neither midfrontal theta oscillations nor the N2, indicating that performance monitoring difficulty influenced conflict resolution but not conflict monitoring.

Multisensory deficits in dyslexia may result from a locus coeruleus attentional network dysfunction

A fundamental educational requirement of beginning reading is to learn, access, and rapidly process associations between novel visuospatial symbols and their phonological representations in speech. Children with difficulties in such cross-modal integration are often divided into dyslexia subtypes, based on whether their primary problem is with the written or spoken component of decoding. The present review suggests that starting in infancy, perceptions of audiovisual speech are integrated by mutual oscillatory phase-resetting between sensory cortices, and throughout development visual and auditory experiences are coupled into unified perceptions. Entirely separate subtypes are incompatible with this view. Visual or auditory deficits will invariably affect processing to some degree in both domains. It is suggested that poor auditory/visual integration may be diagnostic for both forms of dyslexia, stemming from an encoding weakness in the early cross-sensory binding of audiovisual speech. The review presents a model of dyslexia as a dysfunction of the large-scale ventral and dorsal attention networks controlling such binding. Excessive glutamatergic neuronal excitability of the attention networks by the Locus coeruleus-norepinephrine system may interfere with multisensory integration, with deleterious effects on the acquisition of reading by degrading graphene/phoneme conversion.

Is the prefrontal cortex organized by supramodal or modality-specific sensory demands during adolescence?

Attention is inherently biased towards the visual modality during most multisensory scenarios in adults, but the developmental trajectory towards visual dominance has not been fully elucidated. More recent evidence in primates and adult humans suggests a modality-specific stratification of the prefrontal cortex. The current study therefore used functional magnetic resonance imaging (fMRI) to investigate the neuronal correlates of proactive (following cues) and reactive (following probes) cognitive control for simultaneous audio-visual stimulation in 67 healthy adolescents (13-18 years old). Behavioral results were only partially supportive of visual dominance in adolescents, with both reduced response times and accuracy during attend-visual relative to attend-auditory trials. Differential activation of medial and lateral prefrontal cortex for processing incongruent relative to congruent stimuli (reactive control) was also only observed during attend-visual trials. There was no evidence of modality-specific prefrontal cortex stratification during the active processing of multisensory stimuli or during separate functional connectivity analyses. Attention-related modulations were also greater within visual relative to auditory cortex, but were less robust than observed in previous adult studies. Collectively, current results suggest a continued transition towards visual dominance in adolescence, as well as limited modality-specific specialization of prefrontal cortex and attentional modulations of unisensory cortex.

Hemispheric asymmetries in visual mental imagery

Visual mental imagery is the faculty whereby we can "visualize" objects that are not in our line of sight. Longstanding evidence dating back over thirty years has shown that unilateral brain lesions, especially in the left temporal lobe, can impair aspects of this ability. Yet, there is currently no attempt to identify analogies between these neuropsychological findings of hemispheric asymmetry and those from other neuroscientific approaches. Here, we present a critical review of the available literature on the hemispheric laterality of visual mental imagery, by looking at cross-method patterns of evidence in the domains of lesion neuropsychology, neuroimaging, and direct cortical stimulation. Results can be summarized under three main axes. First, frontoparietal networks in both hemispheres appear to be associated with visual mental imagery. Second, lateralization patterns emerge in the temporal lobes, with the left inferior temporal lobe being the most common finding in the literature for endogenously generated images, especially, but not exclusively, when orthographic material is used to ignite imagery. Third, an opposite pattern of hemispheric laterality emerges when visual mental images are induced by exogenous stimulation; direct cortical electrical stimulation tends to produce visual imagery experiences predominantly when applied to the right temporal lobe. These patterns of hemispheric asymmetry are difficult to reconcile with the dominant model of visual mental imagery, which emphasizes the implication of early sensory cortices. They suggest instead that visual mental imagery relies on large-scale brain networks, with a crucial participation of high-level visual regions in the temporal lobes.

Activation of the cognitive control network associated with information uncertainty

The cognitive control network (CCN) that comprises regions of the frontoparietal network, the cingulo-opercular network, and other sub-cortical regions as core structures is commonly activated by events with an increase in information uncertainty. However, it is not clear whether this CCN activation is associated with both information entropy that represents the information conveyed by the context formed by a sequence of events and the surprise that quantifies the information conveyed by a specific type of event in the context. We manipulated entropy and surprise in this functional magnetic resonance imaging study by varying the probability of occurrence of two types of events in both the visual and auditory modalities and measured brain response as a function of entropy and surprise. We found that activation in regions of the CCN increased as a function of entropy and surprise in both the visual and auditory tasks. The frontoparietal network and additional structures in the CCN mediated the relationship between these information measures and behavioral response. These results suggest that the CCN is a high-level modality-general neural entity for the control of the processing of information conveyed by both context and event.