The Semantics of Natural Objects and Tools in the Brain: A Combined Behavioral and MEG Study

Current literature supports the notion that the recognition of objects, when visually presented, is sub-served by neural structures different from those responsible for the semantic processing of their nouns. However, embodiment foresees that processing observed objects and their verbal labels should share similar neural mechanisms. In a combined behavioral and MEG study, we compared the modulation of motor responses and cortical rhythms during the processing of graspable natural objects and tools, either verbally or pictorially presented. Our findings demonstrate that conveying meaning to an observed object or processing its noun similarly modulates both motor responses and cortical rhythms; being natural graspable objects and tools differently represented in the brain, they affect in a different manner both behavioral and MEG findings, independent of presentation modality. These results provide experimental evidence that neural substrates responsible for conveying meaning to objects overlap with those where the object is represented, thus supporting an embodied view of semantic processing.

Time-sensitive Prefrontal Involvement in Associating Confidence With Task Performance Illustrates Metacognitive Introspection in Monkeys

Metacognition refers to the ability to be aware of one’s own cognition. Ample evidence indicates that metacognition in the human primate is highly dissociable from cognition, specialized across domains, and subserved by distinct neural substrates. However, these aspects remain relatively understudied in macaque monkeys. In the present study, we investigated the functionality of macaque metacognition by combining a confidence proxy, hierarchical Bayesian meta-d′ computational modelling, and a single-pulse transcranial magnetic stimulation technique. We found that Brodmann area 46d (BA46d) played a critical role in supporting metacognition independent of task performance; we also found that the critical role in of this region in meta-calculation was time-sensitive. Additionally, we report that macaque metacognition is highly domain-specific with respect to memory and perception decisions. These findings carry implications for our understanding of metacognitive introspection within the primate lineage.

Neural Substrates Associated With Fatigue Symptom In Fibromyalgia

Many patients with fibromyalgia (FM) experience fatigue, but the associated biological mechanisms have not been delineated. We aimed to investigate the neural signatures associated with fatigue severity in patients with FM using MRI. We consecutively recruited 138 patients with FM and collected their clinical profiles and brain-MRI data. We categorized the patients into 3 groups based on their fatigue severity. Using voxel-based morphometry analysis and trend analysis, we first identified neural structures showing volumetric changes associated with fatigue severity, and further explored their seed-to-voxel structural covariance networks (SCNs). Results showed decreased bilateral thalamic volumes were associated with higher severity of fatigue. There was a more widespread distribution of the thalamic SCNs to the frontal, parietal, subcortical, and limbic regions in patients with higher fatigue severity. In addition, increased right inferior temporal cortex volumes were associated with higher severity of fatigue. The right inferior temporal seed showed more SCNs distributions over the temporal cortex and a higher strength of SCNs to the bilateral occipital cortex in patients with higher fatigue severity. The thalamus and the right inferior temporal cortex as well as their altered interactions with cortical and subcortical regions comprise the neural signatures of fatigue in FM.

Testing for implicit emotion regulation in childhood

Although implicit emotion regulation is thought to be critical for psychosocial development and mental wellbeing, few studies have investigated the neural underpinnings of this form of emotion regulation in children. We used a modified emotional Go/NoGo block design fMRI task to explore the neural correlates of implicit emotion regulation and individual differences in a sample of 40 children (50% female, mean age = 8.65 +/- 0.77). Conditions included happy, sad, neutral, and scrambled faces as implicit distractors within the actual Go/NoGo targets. We used a relatively standard preprocessing pipeline via fMRIprep, with T-contrasts for response inhibition and emotional effects, and a nonparametric multiple comparisons procedure, with SnPM, for our group-level analysis. There were multiple significant response inhibition effects, including larger NoGo vs Go activation in the IFG, insula, and MCC/ACC. Valence effects showed significantly greater right putamen activity for the Sad NoGo vs Go contrast and greater bilateral putamen and right pallidum activity for the Happy Go vs Sad Go contrast. These results provide preliminary findings of neural substrates, particularly the putamen, that may be associated with implicit emotion regulation in children.

Neural Substrates for Regulation of Sleep and General Anesthesia

: General anesthesia has been successfully used in the clinic for over 170 years, but its mechanisms of effect remain unclear. Behaviorally, general anesthesia is similar to sleep in that it produces a reversible transition between wakefulness and the state of being unaware of one’s surroundings. A growing discussion has been imposed regarding the common circuits of sleep and general anesthesia, as an increasing number of sleep-arousal regulatory nuclei are reported to participate in the consciousness shift occurring during general anesthesia. Recently, with progress in research technology, both positive and negative evidence for overlapping neural circuits between sleep and general anesthesia have emerged. This article provides a review of the latest evidence on the neural substrates for sleep and general anesthesia regulation by comparing the roles of pivotal nuclei in sleep and anesthesia.

Temporal-sensitive prefrontal involvement in associating confidence with task performance illustrates metacognitive introspection in Old World monkeys (Macaca mulatta)

Metacognition refers to the ability to be aware of one’s own cognition. Ample evidence indicate that metacognition in the human primate is highly dissociable from cognition, specialized across domains, and subserved by distinct neural substrates. However, these aspects remain relatively understudied in the macaque monkeys. Here we investigated the functionality of macaques’ metacognition by combining a confidence proxy, hierarchical Bayesian meta-d’ computational modelling, and single-pulse transcranial magnetic stimulation technique. We found a critical role of Brodmann Area 46d (BA 46d) in supporting metacognition without implicating task performance and its critical time-sensitive role in meta-calculation. We additionally revealed that macaque metacognition is highly domain-specific with respect to memory and perception decisions. These findings carry implications for our understanding of metacognitive introspection within the primate lineage.

Neural Networks Implicated in Autobiographical Memory Training

Training of autobiographical memory has been proposed as intervention to improve cognitive functions. The neural substrates for such improvements are poorly understood. Several brain networks have been previously linked to autobiographical recollections, including the default mode network (DMN) and the sensorimotor network. Here we tested the hypothesis that different neural networks support distinct aspects of memory improvement in response to training on a group of 59 subjects. We found that memory training using olfactory cues increases resting-state intra-network DMN connectivity, and this associates with improved recollection of cue-specific memories. On the contrary, training decreased resting-state connectivity within the sensorimotor network, a decrease that correlated with improved ability for voluntary recall. Moreover, only the decrease in sensorimotor connectivity associated with the training-induced decrease in the TNFα factor, an immune modulation previously linked to improved cognitive performance. We identified functional and biochemical factors that associate with distinct memory processes improved by autobiographical training. Pathways which connect autobiographical memory to both high level cognition and somatic physiology are discussed.

A Narrative Review of Clinical researches of Acupuncture treatment for Depression using Neuroimaging method: Focusing on SCI papers

Objectives: The purpose of this article was to investigate the current status of clinical studies of acupuncture treatment for depression using neuroimaging method, focusing on SCI papers.Methods: We searched for clinical trial studies of acupuncture treatment for depression using neuroimaging method in the MEDLINE (Pubmed), OASIS, and RISS database. Once the online search was finished, studies were selected manually by the inclusion criteria. Finally, we analyzed the characteristics of selected articles and reviewed the neural substrates of acupuncture treatment in depression.Results: Total eight studies were included in this study. The most frequently utilized modality was functional MRI. The most frequently selected acupoint for depression was GV20. Several studies revealed that acupuncture treatment could improve the symptoms of depression. In this manuscript, we demonstrated that neuroimaging techniques could capture the neural substrates associated with depression and acupuncture treatment may modulate the activation of brain areas which were impaired in depression in a different way from sham acupuncture.Conclusions: Utilizing neuroimaging methods to explore neural mechanism of acupuncture treatment on depression would be helpful in clinical trials and more efforts should be needed in this fields.

Synesthesia

People with synesthesia have unusual sensory experiences whereby one stimulus elicits another: Words may evoke tastes, numbers evoke colors, and so on. The eliciting stimulus is called the inducer, whereas the synesthetic experience, which is normally percept-like in quality, is referred to as the concurrent. Synesthetic experiences use some of the same neural substrates as “real” perception. The associations are influenced by cross-modal correspondences between the senses (e.g., high pitch being bright or light) and regularities in one’s own environment. Synesthesia comes in many varieties, but these likely stem from a common cause (because different varieties tend to co-occur together). This is normally explained in terms of an atypical neurodevelopmental cascade from genetic differences that affect brain development and give rise to an atypical profile of behaviors (of which synesthesia is one). People with synesthesia not only have unusual sensory experiences—this being the trait that defines them—but also present with a distinctive cognitive profile (affecting memory, imagery, perception) that has impacts on their life choices (e.g., occupation) and may predispose selectively toward certain clinical vulnerabilities.