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Human Brain Mapping Mar 2022The Self-Attention Network (SAN) has been proposed to describe the underlying neural mechanism of the self-prioritization effect, yet the roles of the key nodes in the...
The Self-Attention Network (SAN) has been proposed to describe the underlying neural mechanism of the self-prioritization effect, yet the roles of the key nodes in the SAN-the left posterior superior temporal sulcus (LpSTS) and the dorsolateral prefrontal cortex (DLPFC)-still need to be clarified. One hundred and nine participants were randomly assigned into the LpSTS group, the DLPFC group, or the sham group. We used the transcranial magnetic stimulation (TMS) technique to selectively disrupt the functions of the corresponding targeted region, and observed its impacts on self-prioritization effect based on the difference between the performance of the self-matching task before and after the targeted stimulation. We analyzed both model-free performance measures and HDDM-based performance measures for the self-matching task. The results showed that the inhibition of LpSTS could lead to reduced performance in processing self-related stimuli, which establishes a causal role for the LpSTS in self-related processing and provide direct evidence to support the SAN framework. However, the results of the DLPFC group from HDDM analysis were distinct from the results based on response efficiency. Our investigation further the understanding of the differentiated roles of key nodes in the SAN in supporting the self-salience in information processing.
Topics: Adult; Attention; Brain Mapping; Dorsolateral Prefrontal Cortex; Ego; Female; Humans; Male; Nerve Net; Psychomotor Performance; Social Perception; Temporal Lobe; Transcranial Magnetic Stimulation; Young Adult
PubMed: 34826160
DOI: 10.1002/hbm.25730 -
Frontiers in Neurology 2021Deep-brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for motor symptoms of advanced Parkinson's disease (PD). Due to a lack of...
Deep-brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for motor symptoms of advanced Parkinson's disease (PD). Due to a lack of detailed somatotopic organization in STN, the clinically most effective part of the STN for stimulation has already become one of the hot research focuses. At present, there are some reports about topographic distribution for different depths within the STN, but few about a mediolateral topography in this area. The objective was to investigate the local field potential (LFP) distribution patterns in dorsomedial and dorsolateral subparts of STN. In total, 18 PD patients eventually enrolled in this study. The DBS electrodes were initially located on the lateral portion of dorsolateral STN. Because of internal capsule side effects presented at low threshold (below 1.5 mA), the electrode was reimplanted more medially to the dorsomedial STN. In this process, intraoperative LFPs from dorsomedial and dorsolateral STN were recorded from the inserted electrode. Both beta power and gamma power of the LFPs were calculated using the power spectral density (PSD) for each DBS contact pair. Furthermore, coherence between any two pairs of contacts was computed in the dorsomedial and dorsolateral parts of STN, respectively. Meanwhile, the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) was monitored prior to surgery and at the 6-month follow-up. Compared to the dorsolateral part of STN, gamma oscillations ( < 0.01) and coherence ( < 0.05) were all weaker in the dorsomedial part. However, no obvious differences in beta oscillations and coherence were observed between the two groups ( > 0.05). Moreover, it should be noted that DBS of the dorsomedial STN resulted in significant improvement in the UPDRS-III in PD patients. There was a 61.50 ± 21.30% improvement in UPDRS-III scores in Med-off/Stim-on state relative to the Med-off state at baseline (from 15.44 ± 6.84 to 43.94 ± 15.79, < 0.01). The specific features of gamma activity may be used to differentiate STN subregions. Moreover, the dorsomedial part of STN might be a potential target for DBS in PD.
PubMed: 34557146
DOI: 10.3389/fneur.2021.710206 -
Psychoneuroendocrinology Jan 2021While high levels of glucocorticoids are generally neuro-damaging, a related adrenal steroid, dehydroepiandrosterone (DHEA), has anti-glucocorticoid and neuroprotective...
While high levels of glucocorticoids are generally neuro-damaging, a related adrenal steroid, dehydroepiandrosterone (DHEA), has anti-glucocorticoid and neuroprotective properties. Previous work has shown increased circulating levels of DHEA and abnormal cortisol/DHEA ratios in people with schizophrenia, however reports are limited and their relationship to neuropathology is unclear. We performed the largest study to date to compare levels of serum DHEA and cortisol/DHEA ratios in people with schizophrenia and healthy controls, and investigated the extent to which cortisol/DHEA ratios predict brain volume. Serum cortisol and DHEA were assayed in 94 people with schizophrenia and 81 healthy controls. T1-weighted high-resolution anatomical scans were obtained using a 3 T Achieva scanner on a subset of 59 people with schizophrenia and 60 healthy controls. Imaging data were preprocessed and analyzed using SPM12. People with schizophrenia had significantly increased serum DHEA levels (p = 0.002), decreased cortisol/DHEA ratios (p = 0.02) and no difference in cortisol levels compared to healthy controls. Cortisol/DHEA ratios were inversely correlated with hippocampal (r = -0.33 p = 0.01) and dorsolateral prefrontal cortex (r = -0.30, p = 0.02) volumes in patients. Our findings suggest that the cortisol/DHEA ratio may be a molecular blood signature of hippocampal and cortical damage. These results further implicate the role of DHEA and hypothalamic-pituitary-adrenal axis dysfunction in the pathophysiology of schizophrenia.
Topics: Case-Control Studies; Dehydroepiandrosterone; Dorsolateral Prefrontal Cortex; Hippocampus; Humans; Hydrocortisone; Organ Size; Schizophrenia
PubMed: 33169678
DOI: 10.1016/j.psyneuen.2020.104916 -
Frontiers in Neuroscience 2023Trust plays an important role in the human economy and people's social lives. Trust is affected by various factors and is related to many brain regions, such as the...
Trust plays an important role in the human economy and people's social lives. Trust is affected by various factors and is related to many brain regions, such as the dorsolateral prefrontal cortex (DLPFC). However, few studies have focused on the impact of the DLPFC on trust through transcranial direct current stimulation (tDCS), although abundant psychology and neuroscience studies have theoretically discussed the possible link between DLPFC activity and trust. In the present study, we aimed to provide evidence of a causal relationship between the rDLPFC and trust behavior by conducting multiple rounds of the classical trust game and applying tDCS over the rDLPFC. We found that overall, anodal stimulation increased trust compared with cathodal stimulation and sham stimulation, while the results in different stages were not completely the same. Our work indicates a causal relationship between rDLPFC excitability and trust behavior and provides a new direction for future research.
PubMed: 37811320
DOI: 10.3389/fnins.2023.1213580 -
The Journal of Neuroscience : the... Mar 2022The shift in control from dorsomedial to dorsolateral striatum during skill and habit formation has been well established, but whether striatal subregions orchestrate...
The shift in control from dorsomedial to dorsolateral striatum during skill and habit formation has been well established, but whether striatal subregions orchestrate this shift cooperatively or competitively remains unclear. Cortical inputs have also been implicated in the shift toward automaticity, but it is unknown whether they mirror their downstream striatal targets across this transition. We addressed these questions using a five step heterogeneous action sequencing task in male rats that is optimally performed by automated chains of actions. By optimizing automatic habitual responding, we discovered that loss of function in the dorsomedial striatum accelerated sequence acquisition. In contrast, loss of function in the dorsolateral striatum impeded acquisition of sequencing, demonstrating functional opposition within the striatum. Unexpectedly, the mPFC was not involved; however, the lateral orbitofrontal cortex was critical. These results shift current theories about striatal control of behavior to a model of competitive opposition, where the dorsomedial striatum interferes with the development of dorsolateral-striatum dependent behavior. We provide the most direct evidence to date that the dorsomedial and dorsolateral striatum compete for control in the acquisition of habitual action sequences. The dorsolateral striatum was critical for sequencing behavior, but loss of dorsomedial striatum function enhanced acquisition. In addition, we found that the mPFC was not required for the formation of automated actions. Using a task that optimizes habitual responding, we demonstrate that the arbitration of dorsomedial and dorsolateral control is not modulated by medial prefrontal cortical activity. However, we find evidence for the role of the lateral orbitofrontal cortex in action sequencing. These results have implications for our understanding of how habits and skills form.
Topics: Animals; Corpus Striatum; Gray Matter; Habits; Male; Neostriatum; Rats
PubMed: 35086903
DOI: 10.1523/JNEUROSCI.1907-21.2022 -
The Journal of Emergency Medicine May 2023Posterior circulation stroke can present with dizziness/vertigo without other general neurological symptoms or signs, making it difficult to detect, and missed stroke... (Review)
Review
BACKGROUND
Posterior circulation stroke can present with dizziness/vertigo without other general neurological symptoms or signs, making it difficult to detect, and missed stroke can deteriorate. Therefore, a sign that can be easily identified during an examination would be helpful to improve the detection of this type of stroke.
OBJECTIVE
The objective of this review is to highlight an ocular sign that is seen in posterior circulation strokes called ocular lateral deviation (OLD). OLD is mostly seen in dorsolateral medullary strokes, and it is also seen in pontine and cerebellar strokes. OLD is detected by asking a patient to look straight ahead and then briefly close their eyes. Upon re-opening their eyes, the examiner will see that the eyes have deviated to one side; the patient's eyes will then make corrective saccade(s) to return to looking straight ahead. Complete eye deviation is a central sign of posterior circulation stroke.
DISCUSSION
OLD is an under-recognized vestibular ocular sign of central vestibulopathies including posterior circulation stroke. The most common location is in the dorsolateral medulla, where one-third of such strokes have complete OLD. Eye deviation can also be appreciated on computed tomography or magnetic resonance imaging. OLD can be detected up to 6 months after a posterior circulation stroke.
CONCLUSIONS
Checking for the sign of complete eye deviation in patients with dizziness/vertigo could be a simple, quick method for detecting posterior circulation stroke, and a means to improving the patients' outcome.
Topics: Humans; Vertigo; Dizziness; Stroke; Eye; Magnetic Resonance Imaging
PubMed: 37037761
DOI: 10.1016/j.jemermed.2023.02.010 -
Scientific Reports Dec 2022In this study we verified the causal role of the bilateral dorsolateral prefrontal cortex (DLPFC) in emotional regulation using a strategy of reappraisal, which involves...
In this study we verified the causal role of the bilateral dorsolateral prefrontal cortex (DLPFC) in emotional regulation using a strategy of reappraisal, which involves intentionally changing the meaning of an affective event to reduce its emotional impact. Healthy participants (n = 26; mean age = 25.4) underwent three sessions of inhibitory continuous theta burst stimulation (cTBS) applied on three different days over the left or right DLPFC, or the vertex. After applying the stimulation protocol participants were presented with neutral and negative pictorial stimuli that had to be either passively watched or reappraised. The efficacy of emotional control was quantified using the Late Positive Potential (LPP), the neural marker of motivated attention and elaborated stimulus processing. The results showed that reappraisal was compromised after inhibitory stimulation of the right DLPFC compared to the vertex. This impairment of affective modulation was reflected in both early (350-750 ms) and late (750-1500 ms) time windows. As no session differences during the passive watching conditions were found, the decrease in reappraisal efficacy due to non-specific changes in basic perceptual processing was considered unlikely. Instead, we suggest that inhibition of the right DLPFC primarily affects the top-down mechanism of attentional deployment. This results in disturbances of attentional processes that are necessary to thoroughly elaborate the content of affective stimuli to enable their new, less negative interpretation.
Topics: Humans; Adult; Transcranial Magnetic Stimulation; Prefrontal Cortex; Dorsolateral Prefrontal Cortex; Inhibition, Psychological; Emotions
PubMed: 36496506
DOI: 10.1038/s41598-022-24629-0 -
Cognitive, Affective & Behavioral... Jun 2023Signals related to uncertainty are frequently observed in regions of the cognitive control network, including anterior cingulate/medial prefrontal cortex (ACC/mPFC),...
Signals related to uncertainty are frequently observed in regions of the cognitive control network, including anterior cingulate/medial prefrontal cortex (ACC/mPFC), dorsolateral prefrontal cortex (dlPFC), and anterior insular cortex. Uncertainty generally refers to conditions in which decision variables may assume multiple possible values and can arise at multiple points in the perception-action cycle, including sensory input, inferred states of the environment, and the consequences of actions. These sources of uncertainty are frequently correlated: noisy input can lead to unreliable estimates of the state of the environment, with consequential influences on action selection. Given this correlation amongst various sources of uncertainty, dissociating the neural structures underlying their estimation presents an ongoing issue: a region associated with uncertainty related to outcomes may estimate outcome uncertainty itself, or it may reflect a cascade effect of state uncertainty on outcome estimates. In this study, we derive signals of state and outcome uncertainty from mathematical models of risk and observe regions in the cognitive control network whose activity is best explained by signals related to state uncertainty (anterior insula), outcome uncertainty (dlPFC), as well as regions that appear to integrate the two (ACC/mPFC).
Topics: Humans; Uncertainty; Magnetic Resonance Imaging; Prefrontal Cortex; Gyrus Cinguli; Cognition
PubMed: 37058212
DOI: 10.3758/s13415-023-01091-7 -
Biological Psychiatry Sep 2022Schizophrenia is associated with reduced numbers of spines and dendrites from layer III of the dorsolateral prefrontal cortex (dlPFC), the layer that houses the... (Review)
Review
Schizophrenia is associated with reduced numbers of spines and dendrites from layer III of the dorsolateral prefrontal cortex (dlPFC), the layer that houses the recurrent excitatory microcircuits that subserve working memory and abstract thought. Why are these synapses so vulnerable, while synapses in deeper or more superficial layers are little affected? This review describes the special molecular properties that govern layer III neurotransmission and neuromodulation in the primate dlPFC and how they may render these circuits particularly vulnerable to genetic and environmental insults. These properties include a reliance on NMDA receptor rather than AMPA receptor neurotransmission; cAMP (cyclic adenosine monophosphate) magnification of calcium signaling near the glutamatergic synapse of dendritic spines; and potassium channels opened by cAMP/PKA (protein kinase A) signaling that dynamically alter network strength, with built-in mechanisms to take dlPFC "offline" during stress. A variety of genetic and/or environmental insults can lead to the same phenotype of weakened layer III connectivity, in which mechanisms that normally strengthen connectivity are impaired and those that normally weaken connectivity are intensified. Inflammatory mechanisms, such as increased kynurenic acid and glutamate carboxypeptidase II expression, are especially detrimental to layer III dlPFC neurotransmission and modulation, mimicking genetic insults. The combination of genetic and inflammatory insults may cross the threshold into pathology.
Topics: Animals; Dorsolateral Prefrontal Cortex; Memory, Short-Term; Prefrontal Cortex; Schizophrenia; Synapses
PubMed: 35305820
DOI: 10.1016/j.biopsych.2022.02.003 -
Journal of Psychiatric Research Jul 2022Studies within the last decade have reported neural and behavioral differences in cognitive control between men with the pedophilic disorder who commit (CSO+) and do not...
Studies within the last decade have reported neural and behavioral differences in cognitive control between men with the pedophilic disorder who commit (CSO+) and do not commit (CSO-) child sexual abuse. Prior studies reported a higher number of errors in Go/Nogo task and lower activity of the prefrontal cortex in NoGo trials, in CSO+ compared with CSO-. Moreover, negative mood was reported as a risk factor for child sexual abuse in pedophilic men. We aimed to examine differences in brain function and behavior between CSO+ and CSO- patients regarding emotional interference on cognitive processes and inhibition. We recruited CSO+ (n = 11) and CSO- (n = 14) patients as well as matched healthy controls (HC) (n = 17). Participants performed the affective Go/NoGo task in a block-design functional magnetic resonance imaging experiment. The task comprised the following four conditions: Negative Go, including only Go stimuli and negatively valenced pictures; Negative NoGo, including 50% of Go and 50% of NoGo trials as well as negatively valenced pictures; and two corresponding conditions with neutral pictures. Brain analysis was restricted to the dorsolateral prefrontal (DLPFC), orbitofrontal, and anterior cingulate cortices. The HC and CSO- groups, but not the CSO+ group, showed significantly slower reactions in negative blocks compared with neutral blocks. Brain analysis revealed increased activation in the right DLPFC during emotional interference contrast (Negative > Neutral) in the HC and CSO- groups; however, there was decreased activation in the CSO+ group. In the CSO+ group, negative distractors did not increase cognitive control processes, which was observed in the CSO- and HC groups at the behavioral and neural levels. These results support previous reports indicating offender status is associated with cognitive and emotional impairments.
Topics: Child; Child Abuse, Sexual; Cognition; Criminals; Dorsolateral Prefrontal Cortex; Emotions; Humans; Magnetic Resonance Imaging; Male; Prefrontal Cortex
PubMed: 35477077
DOI: 10.1016/j.jpsychires.2022.04.012