Scarcity Mindset Neuro Network Decoding With Reward: A Tree-Based Model and Functional Near-Infrared Spectroscopy Study

Resource scarcity imposes challenging demands on the human cognitive system. Insufficient resources cause the scarcity mindset to affect cognitive performance, while reward enhances cognitive function. Here, we examined how reward and scarcity simultaneously contribute to cognitive performance. Experimental manipulation to induce a polar scarcity mindset and reward conditions within participants under functional near-infrared spectroscopy (fNIRS) recording was implemented to explore the mechanism underlying the scarcity mindset and reward in terms of behavior and neurocognition. Participants showed decreased functional connectivity from the dorsolateral prefrontal cortex (DLPFC) to the ventrolateral prefrontal cortex (VLPFC) with a scarcity mindset, a region often implicated in cognitive control. Moreover, under reward conditions, the brain activation of the maximum total Hb bold signal was mainly located in the left hemisphere [channels 1, 3, and 4, left ventrolateral prefrontal cortex (L-VLPFC) and channel 6, left dorsolateral prefrontal cortex (L-DLPFC)], and there was also significant brain activation of the right dorsolateral prefrontal cortex (R-DLPFC) in the right hemisphere (channel 17). Furthermore, these data indicate the underlying neural changes of the scarcity mentality and demonstrate that brain activities may underlie reward processing. Additionally, the base-tree machine learning model was trained to detect the mechanism of reward function in the prefrontal cortex (PFC). According to SHapley Additive exPlanations (SHAP), channel 8 contributed the most important effect, as well as demonstrating a high-level interrelationship with other channels.

Anatomical and functional connectivity support the existence of a salience network node within the caudal ventrolateral prefrontal cortex

Three large-scale brain networks are considered essential to cognitive flexibility: the ventral and dorsal attention (VAN and DAN) and salience (SN) networks. The ventrolateral prefrontal cortex (vlPFC) is a known component of the VAN and DAN, but its role in the SN is controversial. In this study, we used a translational and multimodal approach to demonstrate the existence of a SN node within the vlPFC. First, we used tract-tracing methods in non-human primates (NHP) to quantify the anatomic connectivity strength between the different vlPFC areas and the frontal and insular cortices. The strongest connections with the dorsal anterior cingulate cortex (dACC) and anterior insula (AI) locations comprising the two main cortical SN nodes were derived from the caudal area 47/12. This location also has strong axonal projections to subcortical structures of the salience network, including the dorsomedial thalamus, hypothalamus, sublenticular extended amygdala, and periaqueductal gray. Second, we used a seed-based functional connectivity analysis in NHP resting-state functional MRI (rsfMRI) data to validate the caudal area 47/12 as an SN node. Third, we used the same approach in human rsfMRI data to identify a homologous structure in caudal area 47/12, also showing strong connections with the SN cortical nodes, thus confirming the caudal area 47/12 as the SN node in the vlPFC. Taken together, the vlPFC contains nodes for all three cognitive networks, the VAN, DAN, and SN. Thus, the vlPFC is in a position to switch between these three cognitive networks, suggesting a key role as an attentional hub. Its tight additional connections to the orbitofrontal, dorsolateral, and ventral premotor cortices, places the vlPFC at the center for switching behaviors based on environmental stimuli, computing value and cognitive control.

The development of depressogenic self-schemas: Associations with children's regional grey matter volume in ventrolateral prefrontal cortex

Cognitive theories of depression contend that biased cognitive information processing plays a causal role in the development of depression. Extensive research shows that deeper processing of negative and/or shallower processing of positive self-descriptors (i.e., negative and positive self-schemas) predicts current and future depression in adults and children. However, the neural correlates of the development of self-referent encoding are poorly understood. We examined children's self-referential processing using the self-referent encoding task (SRET) collected from 74 children at ages 6, 9, and 12; around age 10, these children also contributed structural magnetic resonance imaging data. From age 6 to age 12, both positive and negative self-referential processing showed mean-level growth, with positive self-schemas increasing relatively faster than negative ones. Further, voxel-based morphometry showed that slower growth in positive self-schemas was associated with lower regional gray matter volume (GMV) in ventrolateral prefrontal cortex (vlPFC). Our results suggest that smaller regional GMV within vlPFC, a critical region for regulatory control in affective processing and emotion development, may have implications for the development of depressogenic self-referential processing in mid-to-late childhood.

Snapping out of Autopilot: Overriding Habits in Real Time and the Role of Ventrolateral Prefrontal Cortex

Habits allow environmental and interoceptive cues to trigger behavior in an automatized fashion, making them liable to deployment in inappropriate or outdated contexts. Over the long-term, repeated failure of a once adaptive habit to satisfy current goals produces extinction learning that suppresses the habit’s execution. Less attention has been afforded to the mechanisms underlying real-time habit suppression: the capacity to stop the execution of a cued habit that is goal-conflicting. Here, we first posit a model by which goal-relevant stimuli can 1) bring unfolding habits and their projected outcomes into awareness, 2) prompt evaluation of the habit outcome with respect to current goals, and 3) trigger cessation of the habit response if it is determined to be goal-conflicting. Second, we propose a modified stop-signal task to test this model of “goal-directed stopping of habit execution”. Finally, we marshal evidence indicating that the ventrolateral prefrontal cortex (vlPFC), situated at the nexus of salience detection, action-plan assessment, and motor inhibition networks, is uniquely positioned to coordinate the overriding of habitual behaviors in real time. In sum, this review presents a testable model and candidate neurobiological substrate for our capacity to “snap out of autopilot” and override goal-conflicting habits in real time.

#3131 Stimulation of the ventrolateral prefrontal cortex speeds up evidence accumulation in conflictual-uncertain environments

IntroductionEvaluation of the available choices, an integral step in decision-making, leads to the selection of the optimal and most rewarding one. This process of choice selection depends on its features such as value and reward-likelihood, which form the basis for constructs such as Conflict- easy or difficult (difference between reward probabilities of the stimuli-pairs) and Uncertainty- low, medium, or high (inverse U-shaped probability-uncertainty function).The ventrolateral prefrontal cortex (vlPFC) has been implicated in various processes ranging from uncertainty processing to washing behaviours in Obsessive-compulsive disorder (OCD). Here, we target the vlPFC using trans-cranial stimulation, to modulate decision-making behaviours in the context of conflict and uncertainty.MethodsUsing a single-blinded design, we tested 60 healthy controls (30 per group) randomly allocated to either active (continuous theta burst protocol c-TBS) or sham group. The c-TBS protocol used the standard three-pulse burst design repeated every 200ms, with a total of 600 pulses delivered at stimulation intensity set at 80% of the participants Active Motor Threshold. The sham stimulation was delivered with the coil positioned at a 90 angle to the target. Post-stimulation (active or sham), the participants completed 134 trials of the sequential learning paradigm, which consisted of 2 stages. We focused on the second stage of the task, specifically on Conflict and Uncertainty which were used as model dependents of a hierarchical drift-diffusion model(HDDM) to extract the parameters (a- amount of evidence accumulated before making a decision) and the drift rates (v- information processing speed).ResultsUsing the choice and reaction time information as inputs to the HDDM model, we extracted the threshold and drift rates for all conflict and uncertainty conditions. A Bayesian repeated-measures ANOVA on threshold showed a very strong evidence for the main effect of conflict-uncertainty condition (BF10 = 5.2 x 1010) and stimulation by condition interaction (BF10 = 6.4 x 103) but no main effect of stimulation (BF10 = 0.46). A Bayesian Independent samples t-test showed strong evidence (BF10 = 77.54) for stimulation to speed up the decision-making process, by decreasing the amount of evidence accumulated (threshold)whilst selecting a choice in a difficult uncertain scenario.ConclusionsBy applying an inhibitory based stimulation protocol tovlPFC, we show a modulation in behaviour specific to context, where the choices are similar in value but their reward likelihood being uncertain. This finding has key implications to the design of novel interventions for OCD.

Distinctive responses in anterior temporal lobe and ventrolateral prefrontal cortex during categorization of semantic information

Semantic categorization is a fundamental ability in language as well as in interaction with the environment. However, it is unclear what cognitive and neural basis generates this flexible and context dependent categorization of semantic information. We performed behavioral and fMRI experiments with a semantic priming paradigm to clarify this. Participants conducted semantic decision tasks in which a prime word preceded target words, using names of animals (mammals, birds, or fish). We focused on the categorization of unique marine mammals, having characteristics of both mammals and fish. Behavioral experiments indicated that marine mammals were semantically closer to fish than terrestrial mammals, inconsistent with the category membership. The fMRI results showed that the left anterior temporal lobe was sensitive to the semantic distance between prime and target words rather than category membership, while the left ventrolateral prefrontal cortex was sensitive to the consistency of category membership of word pairs. We interpreted these results as evidence of existence of dual processes for semantic categorization. The combination of bottom-up processing based on semantic characteristics in the left anterior temporal lobe and top-down processing based on task and/or context specific information in the left ventrolateral prefrontal cortex is required for the flexible categorization of semantic information.