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Introduction: Low self-esteem is a frequent symptom in major depressive disorder (MDD). This functional magnetic resonance imaging study investigated whether MDD patients with low self-esteem show a distinct neural pathophysiology. Previous studies linked low self-esteem to reduced task-induced deactivation of the pregenual anterior cingulate cortex (pgACC) as a part of the default mode network, and to reduced connectivity between pgACC and reward system. Goya-Maldonado et al. identified an MDD subtype with pgACC and ventral striatal overactivations during reward processing. We hypothesized that this subtype might be characterized by low self-esteem., Methods: Eighty-three MDD patients performed the desire-reason dilemma task and completed the Rosenberg Self-Esteem Scale (RSES). Brain activity during bottom-up reward processing was regressed upon the RSES scores, controlling for depression severity measured by the Montgomery-Åsberg Depression Rating Scale. To corroborate the findings, we compared self-esteem scores between patient subgroups with impaired task-induced deactivation (n = 31) and with preserved task-induced deactivation (n = 31) of the pgACC., Results: Consistent with our a priori hypothesis, activity in a bilateral fronto-striatal network including pgACC and ventral striatum correlated negatively with RSES scores, also when controlling for depression severity. In the additional analysis, patients with impaired task-induced pgACC deactivation showed lower self-esteem (t (52.82) = -2.27; p = .027, d = 0.58) compared to those with preserved task-induced pgACC deactivation., Conclusions: We conclude that low self-esteem in MDD patients is linked to a task-induced deactivation dysfunction of the pgACC. Our findings suggest that a previously described possible subtype of MDD with pgACC and ventral striatal overactivations during reward processing is clinically characterized by low self-esteem., (© 2024 The Author(s). Brain and Behavior published by Wiley Periodicals LLC.)

The ability to empathize with another person's inner experience is believed to be a central element of our social interactions. Previous research has focused on cognitive (e.g., theory of mind) and emotional (e.g., emotional contagion) empathy, and less on behavioral factors (i.e., the ability to respond empathically). Recent studies suggest that the Default Mode Network (DMN) mediates individual variability in distinct empathy-related behaviors. However, little is known about DMN activity during actual empathic responses, understood in this study as the ability to communicate our understanding of the others' experience back to them. This study used an empathy response paradigm with 28 participants (22-37 years old) to analyze the relationship between the quality of empathic responses to 14 empathy-eliciting vignettes and patterns of attenuation in the DMN. Overall, the results suggest that high levels of empathic response, are associated with sustained activation of the DMN when compared with lower levels of empathy. Our results demonstrate that the DMN becomes increasingly involved in empathy-related behavior, as our level of commitment to the other's experience increases. This study represents a first attempt to understand the relation between the capacity for responding in a supportive way to others' needs and the intra-individual variability of the pattern of the DMN attenuation. Here we underline the critical role that the DMN plays in high-level social cognitive processes and corroborate the DMN role in different psychiatric disorders associated with a lack of empathy., (© 2022 Published by Elsevier B.V.)

Prenatal exposure to polychlorinated biphenyls (PCBs), persistent organic pollutants in food chains and environment, exerts negative effects on children's cognitive function. To study the long-term effects, we examined cognitive functions in the male children of women with substantial PCB exposure in Taiwan during 1978-1979 and investigated neural basis of cognitive function changes through structural magnetic resonance imaging (MRI) and functional MRI (fMRI), which included resting-state and task-activated fMRI with two paradigms: a 2-back task and a picture rotation task. Ten men aged 30.0 ± 3.7 years with prenatal exposure to PCBs and 11 unexposed controls aged 28.1 ± 3.1 years participated. Both groups had similar cognitive phenotypes and behavioral results. Structural MRI analysis results showed that the PCB group had increased cortical thickness over the right inferior parietal lobule. In the resting-state study, the PCB group showed alterations in the default mode network. During the tasks, the PCB group showed decreased task-induced deactivation signals in cognition-associated brain areas during the 2-back task but enhanced deactivations during the picture rotation task. This study demonstrated altered structural MRI as well as resting and task-related fMRI in men with prenatal PCB exposure, suggesting altered brain plasticity and compensatory neuropsychological performance., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Detailed studies on the association between neural oscillations and the neurotransmitters gamma-aminobutyric acid (GABA) and glutamate have been performed in vitro. In addition, recent functional magnetic resonance imaging studies have characterized these neurotransmitters in task-induced deactivation processes during a working memory (WM) task. However, few studies have investigated the relationship between these neurotransmitters and task-induced oscillatory changes in the human brain. Here, using combined magnetoencephalography (MEG) and magnetic resonance spectroscopy (MRS), we investigated the modulation of GABA and glutamate + glutamine (Glx) concentrations related to task-induced oscillations in neural activity during a WM task. We first acquired resting-state MRS and MEG data from 20 healthy male volunteers using the n-back task. Time-frequency analysis was employed to determine the power induced during the encoding and retention phases in perigenual anterior cingulate cortex (pg-ACC), mid-ACC, and occipital cortex (OC). Statistical analysis showed that increased WM load was associated with task-induced oscillatory modulations (TIOMs) of the theta-gamma band relative to the zero-back condition (TIOM0B) in each volume of interest during the encoding phase of the n-back task. The task-induced oscillatory modulations in the two-back condition relative to the zero-back condition (TIOM2B-0B) were negatively correlated with the percent rate change of the correct hit rate for 2B-0B, but positively correlated with GABA/Glx. The positive correlation between TIOM2B-0B and GABA/Glx during the WM task indicates the importance of the inhibition/excitation ratio. In particular, a low inhibition/excitation ratio is essential for the efficient inhibition of irrelevant neural activity, thus producing precise task performance., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Cognitive abilities decline with age, but with considerable individual variation. The neurobiological correlate of this variation is not well described. Functional brain imaging studies have demonstrated reduced task-induced deactivation (TID) of the brain's default mode network (DMN) in a wide range of neurodegenerative diseases involving cognitive symptoms, in conditions with increased risk of Alzheimer's disease, and even in advanced but healthy aging. Here, we investigated brain activation and deactivation during a visual-motor task in 185 clinically healthy males from a Danish birth cohort, whose cognitive function was assessed in youth and midlife. Using each individual as his own control, we defined a group with a large degree of cognitive decline, and a control group. When correcting for effects of total cerebral blood flow and hemoglobin level, we found reduced TID in the posterior region of the DMN in the cognitive decline group compared to the control group. Furthermore, increased visual activation response was found in the cognitive decline group, indicating that the TID reduction was not exclusively due to overall impaired vascular reactivity. These results suggest a neurobiological basis for subclinical cognitive decline in late midlife, which includes TID alterations similar to the pattern seen in patients with AD and mild cognitive impairment. Hence, TID reduction might be suggested as an early marker for subtle cognitive decline in aging., (Copyright © 2014 Wiley Periodicals, Inc.)