The transition to motherhood: linking hormones, brain and behaviour.

We are witnessing a stark increase in scientific interest in the neurobiological processes associated with pregnancy and maternity. Convergent evidence suggests that around the time of labour, first-time mothers experience a specific pattern of neuroanatomical changes that are associated with maternal behaviour. Here we provide an overview of the human neurobiological adaptations of motherhood, focusing on the interplay between pregnancy-related steroid and peptide hormones, and neuroplasticity in the brain. We discuss which brain plasticity mechanisms might underlie the structural changes detected by MRI, which hormonal systems are likely to contribute to such neuroanatomical changes and how these brain mechanisms may be linked to maternal behaviour. This Review offers an overarching framework that can serve as a roadmap for future investigations.

Brain activity and connectivity differences in reward value discrimination during effort computation in schizophrenia.

Negative symptoms in the motivational domain are strongly correlated with deficits in social and occupational functioning in schizophrenia. However, the neural substrates underlying these symptoms remain largely unknown. Twenty-eight adults with schizophrenia and twenty healthy volunteers underwent functional magnetic resonance while completing a lottery game designed to capture reward-related cognitive processes. Each trial demanded an initial investment of effort in form of key presses to increase the odds of winning. Brain activity in response to different reward cues (1 euro versus 1 cent) was compared between groups. Whereas controls invested more effort in improving their chances to win 1 euro compared to 1 cent in the lottery game, patients invested similarly high amounts of effort in both reward conditions. The neuroimaging analysis revealed lower neural activity in the bilateral caudate and cingulo-opercular circuits and decreased effective connectivity between reward-associated areas and neural nodes in the frontoparietal and salience network in response to high- versus low-reward conditions in schizophrenia patients compared to controls. Effective connectivity differences across conditions were associated with amotivation symptoms in patients. Overall, our data provide the evidence of alterations in neural activity in the caudate and cingulo-opercular "task maintenance" circuits and frontoparietal effective connectivity with reward-associated nodes as possible underlying mechanisms of reward value discrimination deficits affecting effort computation in schizophrenia.

Stepwise functional connectivity reveals altered sensory-multimodal integration in medication-naïve adults with attention deficit hyperactivity disorder.

Neuroimaging studies indicate that children with attention-deficit/hyperactivity disorder (ADHD) present alterations in several functional networks of the sensation-to-cognition spectrum. These alterations include functional overconnectivity within sensory regions and underconnectivity between sensory regions and neural hubs supporting higher order cognitive functions. Today, it is unknown whether this same pattern of alterations persists in adult patients with ADHD who had never been medicated for their condition. The aim of the present study was to assess whether medication-naïve adults with ADHD presented alterations in functional networks of the sensation-to-cognition spectrum. Thirty-one medication-naïve adults with ADHD and twenty-two healthy adults underwent resting-state functional magnetic resonance imaging (rs-fMRI). Stepwise functional connectivity (SFC) was used to characterize the pattern of functional connectivity between sensory seed regions and the rest of the brain at direct, short, intermediate, and long functional connectivity distances, thus covering the continuum from the sensory input to the neural hubs supporting higher order cognitive functions. As compared to controls, adults with ADHD presented increased SFC degree within primary sensory regions and decreased SFC degree between sensory seeds and higher order integration nodes. In addition, they exhibited decreased connectivity degree between sensory seeds and regions of the default-mode network. Consistently, the higher the score in clinical severity scales the lower connectivity degree between seed regions and the default mode network.

Pregnancy and adolescence entail similar neuroanatomical adaptations: A comparative analysis of cerebral morphometric changes.

Mapping the impact of pregnancy on the human brain is essential for understanding the neurobiology of maternal caregiving. Recently, we found that pregnancy leads to a long-lasting reduction in cerebral gray matter volume. However, the morphometric features behind the volumetric reductions remain unexplored. Furthermore, the similarity between these reductions and those occurring during adolescence, another hormonally similar transitional period of life, still needs to be investigated. Here, we used surface-based methods to analyze the longitudinal magnetic resonance imaging data of a group of 25 first-time mothers (before and after pregnancy) and compare them to those of a group of 25 female adolescents (during 2 years of pubertal development). For both first-time mothers and adolescent girls, a monthly rate of volumetric reductions of 0.09 mm3 was observed. In both cases, these reductions were accompanied by decreases in cortical thickness, surface area, local gyrification index, sulcal depth, and sulcal length, as well as increases in sulcal width. In fact, the changes associated with pregnancy did not differ from those that characterize the transition during adolescence in any of these measures. Our findings are consistent with the notion that the brain morphometric changes associated with pregnancy and adolescence reflect similar hormonally primed biological processes.

Local functional connectivity suggests functional immaturity in children with attention-deficit/hyperactivity disorder.

Previous studies have associated Attention-Deficit/Hyperactivity Disorder (ADHD) with a maturational lag of brain functional networks. Functional connectivity of the human brain changes from primarily local to more distant connectivity patterns during typical development. Under the maturational lag hypothesis, we expect children with ADHD to exhibit increased local connectivity and decreased distant connectivity compared with neurotypically developing (ND) children. We applied a graph-theory method to compute local and distant connectivity levels and cross-sectionally compared them in a sample of 120 children with ADHD and 120 age-matched ND children (age range = 7-17 years). In addition, we measured if potential group differences in local and distant connectivity were stable across the age range considered. Finally, we assessed the clinical relevance of observed group differences by correlating the connectivity levels and ADHD symptoms severity separately for each group. Children with ADHD exhibited more local connectivity than age-matched ND children in multiple brain regions, mainly overlapping with default mode, fronto-parietal and ventral attentional functional networks (p < .05- threshold free-cluster enhancement-family-wise error). We detected an atypical developmental pattern of local connectivity in somatomotor regions, that is, decreases with age in ND children, and increases with age in children with ADHD. Furthermore, local connectivity within somatomotor areas correlated positively with clinical severity of ADHD symptoms, both in ADHD and ND children. Results suggest an immature functional state of multiple brain networks in children with ADHD. Whereas the ADHD diagnosis is associated with the integrity of the system comprising the fronto-parietal, default mode and ventral attentional networks, the severity of clinical symptoms is related to atypical functional connectivity within somatomotor areas. Additionally, our findings are in line with the view of ADHD as a disorder of deviated maturational trajectories, mainly affecting somatomotor areas, rather than delays that normalize with age.

Reduced willingness to invest effort in schizophrenia with high negative symptoms regardless of reward stimulus presentation and reward value.

BACKGROUND: Negative symptoms in schizophrenia, which are related to poor functioning, are thought to be grounded on aberrant functioning in the reward system. We aimed to disentangle how negative symptoms and two cognitive aspects of goal-directed behavior, mental representation of reward and reward value, affect willingness to invest effort to attain a reward in schizophrenia. AIMS AND PROCEDURES: To this purpose, 43 schizophrenia patients and 35 healthy controls were assessed for negative symptoms and general functioning, and completed an effort-based reward task. Patients were split in high and low negative symptoms scorers. A series of ANOVA tests were conducted in order to test the effects of group controlling for representation of reward (Task 1) and balance between reward value and effort (Task 2) on will to invest effort to attain a reward. MAIN FINDINGS: Schizophrenia patients with high negative symptoms chose to invest lower amounts of effort for a reward compared both to low negative symptoms patients and to controls in both tasks. Neither mental representation of reward (Task 1) nor reward value (Task 2) did differentially affect will to invest effort between-groups. CONCLUSIONS: These findings suggest that the lower willingness to invest effort observed in schizophrenia patients with high negative symptoms may not be related to cognitive aspects of goal-oriented behavior.

Just-in-time response to reward as a function of ADHD symptom severity.

AIM: Attention-deficit hyperactivity disorder (ADHD) neuroimaging studies have identified substantial differences in reward-related circuits on a trial-by-trial basis. However, no research to date has evaluated the effect of motivational context on neural activity in settings with intermittent reward in ADHD. The present study was designed to identify neural processes underlying both immediate effects of reward and sustained effects of reward associated with motivational context in adult ADHD patients. METHODS: We used a functional magnetic resonance imaging paradigm, including a time estimation task with constant versus intermittent reward conditions, in a sample of 21 medication-naïve adults with combined ADHD and 24 healthy adults. RESULTS: Although no between-group neural differences were detected, orbitofrontal activity dropped in association with high ADHD symptom severity during the transition from initial non-reward context blocks to subsequent reward context blocks. In turn, ADHD symptom severity predicted higher orbitofrontal activity in response to immediate reward versus no reward within reward context blocks. CONCLUSION: These results suggest that high ADHD symptom severity scorers adopted a 'just-in-time' strategy, involving the recruitment of reward processing brain areas in the face of immediate reward rather than a sustained response to motivational context.

Updating the identity-based model of belief: From false belief to the spread of misinformation.

The spread of misinformation threatens democratic societies, hampering informed decision-making. Partisan identity biases perceptions of reality, promoting false beliefs. The Identity-based Model of Political Belief explains how social identity shapes information processing and contributes to misinformation. According to this model, social identity goals can override accuracy goals, leading to belief alignment with party members rather than facts. We propose an extended version of this model that incorporates the role of informational context in misinformation belief and sharing. Partisanship involves cognitive and motivational aspects that shape party members' beliefs and actions. This includes whether they seek further evidence, where they seek that evidence, and which sources they trust. Understanding the interplay between social identity and accuracy is crucial in addressing misinformation.

The Misleading count: an identity-based intervention to counter partisan misinformation sharing.

Interventions to counter misinformation are often less effective for polarizing content on social media platforms. We sought to overcome this limitation by testing an identity-based intervention, which aims to promote accuracy by incorporating normative cues directly into the social media user interface. Across three pre-registered experiments in the US (N = 1709) and UK (N = 804), we found that crowdsourcing accuracy judgements by adding a Misleading count (next to the Like count) reduced participants' reported likelihood to share inaccurate information about partisan issues by 25% (compared with a control condition). The Misleading count was also more effective when it reflected in-group norms (from fellow Democrats/Republicans) compared with the norms of general users, though this effect was absent in a less politically polarized context (UK). Moreover, the normative intervention was roughly five times as effective as another popular misinformation intervention (i.e. the accuracy nudge reduced sharing misinformation by 5%). Extreme partisanship did not undermine the effectiveness of the intervention. Our results suggest that identity-based interventions based on the science of social norms can be more effective than identity-neutral alternatives to counter partisan misinformation in politically polarized contexts (e.g. the US). This article is part of the theme issue 'Social norm change: drivers and consequences'.

Women's neuroplasticity during gestation, childbirth and postpartum.

Pregnancy is a unique neuroplastic period in adult life. This longitudinal study tracked brain cortical changes during the peripartum period and explored how the type of childbirth affects these changes. We collected neuroanatomic, obstetric and neuropsychological data from 110 first-time mothers during late pregnancy and early postpartum, as well as from 34 nulliparous women evaluated at similar time points. During late pregnancy, mothers showed lower cortical volume than controls across all functional networks. These cortical differences attenuated in the early postpartum session. Default mode and frontoparietal networks showed below-expected volume increases during peripartum, suggesting that their reductions may persist longer. Results also pointed to different cortical trajectories in mothers who delivered by scheduled C-section. The main findings were replicated in an independent sample of 29 mothers and 24 nulliparous women. These data suggest a dynamic trajectory of cortical decreases during pregnancy that attenuates in the postpartum period, at a different rate depending on the brain network and childbirth type.

The Costs of Polarizing a Pandemic: Antecedents, Consequences, and Lessons.

Polarization has been rising in the United States of America for the past few decades and now poses a significant-and growing-public-health risk. One of the signature features of the American response to the COVID-19 pandemic has been the degree to which perceptions of risk and willingness to follow public-health recommendations have been politically polarized. Although COVID-19 has proven more lethal than any war or public-health crisis in American history, the deadly consequences of the pandemic were exacerbated by polarization. We review research detailing how every phase of the COVID-19 pandemic has been polarized, including judgments of risk, spatial distancing, mask wearing, and vaccination. We describe the role of political ideology, partisan identity, leadership, misinformation, and mass communication in this public-health crisis. We then assess the overall impact of polarization on infections, illness, and mortality during the pandemic; offer a psychological analysis of key policy questions; and identify a set of future research questions for scholars and policy experts. Our analysis suggests that the catastrophic death toll in the United States was largely preventable and due, in large part, to the polarization of the pandemic. Finally, we discuss implications for public policy to help avoid the same deadly mistakes in future public-health crises.

The role of political devotion in sharing partisan misinformation and resistance to fact-checking.

Online misinformation is disproportionality created and spread by people with extreme political attitudes, especially among the far-right. There is a debate in the literature about why people spread misinformation and what should be done about it. According to the purely cognitive account, people largely spread misinformation because they are lazy, not biased. According to a motivational account, people are also motivated to believe and spread misinformation for ideological and partisan reasons. To better understand the psychological and neurocognitive processes that underlie misinformation sharing among the far-right, we conducted a cross-cultural experiment with conservatives and far-right partisans in the Unites States and Spain (N = 1,609) and a neuroimaging study with far-right partisans in Spain (N = 36). Far-right partisans in Spain and U.S. Republicans who highly identify with Trump were more likely to share misinformation than center-right voters and other Republicans, especially when the misinformation was related to sacred values (e.g., immigration). Sacred values predicted misinformation sharing above and beyond familiarity, attitude strength, and salience of the issue. Moreover, far-right partisans were unresponsive to fact-checking and accuracy nudges. At a neural level, this group showed increased activity in brain regions implicated in mentalizing and norm compliance in response to posts with sacred values. These results suggest that the two components of political devotion-identity fusion and sacred values-play a key role in misinformation sharing, highlighting the identity-affirming dimension of misinformation sharing. We discuss the need for motivational and identity-based interventions to help curb misinformation for high-risk partisan groups. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Social norms (not threat) mediate willingness to sacrifice in individuals fused with the nation: Insights from the COVID-19 pandemic.

Identity fusion with the community has been previously found to mediate altruism in post-disaster settings. However, whether this altruistic response is specifically triggered by ingroup threat, or whether it can also be triggered by global threats remains unclear. We evaluated willingness to sacrifice in the context of the COVID-19 pandemic across three survey waves. Against expectations, participants fused with the nation (vs. non-fused) did not differentially respond to a national versus global threat condition. Conversely, social norms decisively influenced willingness to sacrifice in this sample, with fused individuals with stronger norms about social distancing reporting the highest altruistic response during the first weeks of the pandemic. Longitudinally, after an initial peak in the altruistic response, deteriorating social norms mediated decreases in willingness to sacrifice in individuals fused with the nation (vs. non-fused). Implications of these results for the development of interventions aimed to address global challenges are discussed.

How social identity shapes conspiratorial belief.

While conspiracy theories may offer benefits to those who believe in them, they can also foster intergroup conflict, threaten democracy, and undercut public health. We argue that the motivations behind conspiracy theory belief are often related to social identity. Conspiracy theories are well-positioned to fulfill social identity needs such as belongingness goals, the need to think highly of one's in-group, and the need to feel secure in one's group status. Understanding the social motives that attract people to conspiracy theories should be a focus of future research, and may be key to creating more successful interventions to reduce socially harmful conspiracy theories.

Local Functional Connectivity as a Parsimonious Explanation of the Main Frameworks for ADHD in Medication-Naïve Adults.

Objective: Neuroimaging studies in children with ADHD indicate that their brain exhibits an atypical functional connectivity pattern characterized by increased local connectivity and decreased distant connectivity. We aim to evaluate if the local and distant distribution of functional connectivity is also altered in adult samples with ADHD who have never received medication before. Methods: We compared local and distant functional connectivity between 31 medication-naïve adults with ADHD and 31 healthy controls and tested whether this pattern was associated with symptoms severity scores. Results: ADHD sample showed increased local connectivity in the dACC and the SFG and decreased local connectivity in the PCC. Conclusion: Results parallel those obtained in children samples suggesting a deficient integration within the DMN and segregation between DMN, FPN, and VAN. These results are consistent with the three main frameworks that explain ADHD: the neurodevelopmental delay hypothesis, the DMN interference hypothesis, and multi-network models.

Local Functional Connectivity as a Parsimonious Explanation of the Main Frameworks for ADHD in Medication-Naïve Adults.

OBJECTIVE: Neuroimaging studies in children with ADHD indicate that their brain exhibits an atypical functional connectivity pattern characterized by increased local connectivity and decreased distant connectivity. We aim to evaluate if the local and distant distribution of functional connectivity is also altered in adult samples with ADHD who have never received medication before. METHODS: We compared local and distant functional connectivity between 31 medication-naïve adults with ADHD and 31 healthy controls and tested whether this pattern was associated with symptoms severity scores. RESULTS: ADHD sample showed increased local connectivity in the dACC and the SFG and decreased local connectivity in the PCC. CONCLUSION: Results parallel those obtained in children samples suggesting a deficient integration within the DMN and segregation between DMN, FPN, and VAN. These results are consistent with the three main frameworks that explain ADHD: the neurodevelopmental delay hypothesis, the DMN interference hypothesis and multi-network models.

Presence of Distractor Improves Time Estimation Performance in an Adult ADHD Sample.

Objective: It is widely accepted that patients with ADHD exhibit greater susceptibility to distractors, especially during tasks with higher working memory load demands. However, no study to date has specifically measured the impact of distractors on timing functions, although these have consistently shown alterations in ADHD. In this investigation, we aimed to elucidate the neural mechanisms mediating distractor effects on timing functions. Method: We employed a time estimation functional magnetic resonance imaging (fMRI) paradigm including a distracting element in half of the trials in a sample of 21 patients with ADHD and 24 healthy controls. Results: As expected, the effect of the distractor was greater in ADHD patients, where it was associated with increased orbitofrontal activity compared with controls. Behaviorally, time estimation performance benefited from the presence of distractors in both groups. In turn, such improvement correlated with medial frontal and insular activity in the brain. Conclusion: These results suggest that distractors could be stimulating recruitment of frontal resources in ADHD, thus contributing to increase focus on the task.

The Paternal Transition Entails Neuroanatomic Adaptations that are Associated with the Father's Brain Response to his Infant Cues.

The transition into fatherhood is a life-changing event that requires substantial psychological adaptations. In families that include a father figure, sensitive paternal behavior has been shown to positively impact the infant's development. Yet, studies exploring the neuroanatomic adaptations of men in their transition into fatherhood are scarce. The present study used surface-based methods to reanalyze a previously published prospective magnetic resonance imaging dataset comprised of 20 first-time fathers (preconception-to-postpartum) and 17 childless men. We tested if the transition into fatherhood entailed changes in cortical volume, thickness, and area and whether these changes were related to 2 indicators of paternal experience. Specifically, we tested if such changes were associated with (1) the baby's age and/or (2) the fathers' brain activity in response to pictures of their babies compared with an unknown baby. Results indicated that first-time fathers exhibited a significant reduction in cortical volume and thickness of the precuneus. Moreover, higher volume reduction and cortical thinning were associated with stronger brain responses to pictures of their own baby in parental brain regions. This is the first study showing preconception-to-postpartum neuroanatomical adaptations in first-time fathers associated with the father's brain response to cues of his infant.