Neural Dynamics in the Processing of Personal Objects as an Index of the Brain Representation of the Self Abstract Across time, personal belongings incorporate semantic self-knowledge contributing to the subjective meaning of mineness and preference, whose access is prioritized. Although neuroimaging is starting to explore self-knowledge processes, more research is still necessary to better understand many aspects of these processes. One, the timing of the mechanisms involved, is the main purpose of the present study. Here, we investigate the differential patterns of event-related brain potentials and the underlying dynamic causal connectivity between neural generators to self-related objects ranging in self-relevance, as compared to non-personal-related objects. Personal objects elicited lower N2 and higher P3 components compared to non-personal objects, and those with high relevance showed the lowest N2 and the highest P3 amplitudes. Brain sources connectivity corresponding to N2–P3 ERP complex revealed an early connectivity between posterior cingulate/precuneus and parahippocampal gyrus, common for both types of objects. However, this parietal connectivity was kept in later latencies only for personal objects, also intervening the anterior cingulate as the main driver of information flow to the parietal network. Personal objects showed more extensive connectivity between parietal areas and these with anterior cingulate. These findings provide new evidence of a neural connectivity and its temporal course underlying the interplay of lower-level and higher-level cognitive processes relative to personal objects. Further, the results offer new insights on how superordinate mental representations enable distinctive processing of relevant belongings, starting relatively early in time.

Predicting Patient Reported Outcomes of Cognitive Function Using Connectome-Based Predictive Modeling in Breast Cancer Abstract Being able to predict who will likely experience cancer related cognitive impairment (CRCI) could enhance patient care and potentially reduce economic and human costs associated with this adverse event. We aimed to determine if post-treatment patient reported CRCI could also be predicted from baseline resting state fMRI in patients with breast cancer. 76 newly diagnosed patients (n = 42 planned for chemotherapy; n = 34 not planned for chemotherapy) and 50 healthy female controls were assessed at 3 times points [T1 (prior to treatment); T2 (1 month post chemotherapy); T3 (1 year after T2)], and at yoked intervals for controls. Data collection included self-reported executive dysfunction, memory function, and psychological distress and resting state fMRI data converted to connectome matrices for each participant. Statistical analyses included linear mixed modeling, independent t tests, and connectome-based predictive modeling (CPM). Executive dysfunction increased over time in the chemotherapy group and was stable in the other two groups (p < 0.001). Memory function decreased over time in both patient groups compared to controls (p < 0.001). CPM models successfully predicted executive dysfunction and memory function scores (r > 0.31, p < 0.002). Support vector regression with a radial basis function (SVR RBF) showed the highest performance for executive dysfunction and memory function (r = 0.68; r = 0.44, p’s < 0.001). Baseline neuroimaging may be useful for predicting patient reported cognitive outcomes which could assist in identifying patients in need of surveillance and/or early intervention for treatment-related cognitive effects.

Finger Tapping Task Activation vs. TMS Hotspot: Different Locations and Networks Abstract Both functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) have been used to non-invasively localize the human motor functional area. These locations can be clinically used as stimulation target of TMS treatment. However, it has been reported that the finger tapping fMRI activation and TMS hotspot were not well-overlapped. The aim of the current study was to measure the distance between the finger tapping fMRI activation and the TMS hotspot, and more importantly, to compare the network difference by using resting-state fMRI. Thirty healthy participants underwent resting-state fMRI, task fMRI, and then TMS hotspot localization. We found significant difference of locations between finger tapping fMRI activation and TMS hotspot. Specifically, the finger tapping fMRI activation was more lateral than the TMS hotspot in the premotor area. The fMRI activation peak and TMS hotspot were taken as seeds for resting-state functional connectivity analyses. Compared with TMS hotspot, finger tapping fMRI activation peak showed more intensive functional connectivity with, e.g., the bilateral premotor, insula, putamen, and right globus pallidus. The findings more intensive networks of finger tapping activation than TMS hotspot suggest that TMS treatment targeting on the fMRI activation area might result in more remote effects and would be more helpful for TMS treatment on movement disorders.

Electrophysiological Processes on Motor Imagery Mediate the Association Between Increased Gray Matter Volume and Cognition in Amnestic Mild Cognitive Impairment Abstract Motor imagery is considered as an ideal window to observe neural processes of action representations. Behavioral evidence has indicated an alteration of motor imagery in amnestic mild cognitive impairment (aMCI). However, it still remains unclear on the altered neurophysiological processing mechanism of motor imagery and whether this mechanism links the abnormal biological basis of motor imagery with impaired cognition in aMCI. This study was to investigate the altered neurophysiological processing mechanism of motor imagery and to examine the relationships between this knowledge and the altered structural basis of motor imagery with impaired cognition in aMCI. A hand mental rotation paradigm was used to manipulate the processing of motor imagery while event-related brain potentials (ERPs) were recorded and gray matter (GM) voxel-based morphometry was performed in 20 aMCI and 29 healthy controls. Compared with controls, aMCI exhibited lower ERP amplitudes in parietal cortex and higher ERP amplitudes in frontal cortex during motor imagery. In addition, aMCI showed reduced GM volumes in cerebellum posterior lobe, insula and hippocampus/parahippocampal gyrus, and increased GM volumes in middle cingulate gyrus and superior frontal gyrus. Most importantly, increased ERP amplitude significantly mediated the association between increased GM and cognition. This study provided a novel evidence for the relationships between the electrophysiological processing mechanism and structural basis of motor imagery with impaired cognition in aMCI. It suggests that improving neural activity by stimulating the frontal lobe can potentially contribute to acquire motor imagery skills for neurological rehabilitation in aMCI subjects.

Current Opinions in Brain Imaging Methods and Applications

Magnetic Resonance Imaging of Human Olfactory Dysfunction Abstract Olfactory dysfunctions affect a larger portion of population (up to 15% with partial olfactory loss, and 5% with complete olfactory loss) as compared to other sensory dysfunctions (e.g. auditory or visual) and have a negative impact on the life quality. The impairment of olfactory functions may happen at each stage of the olfactory system, from epithelium to cortex. Non-invasive neuroimaging techniques such as the magnetic resonance imaging (MRI) have advanced the understanding of the advent and progress of olfactory dysfunctions in humans. The current review summarizes recent MRI studies on human olfactory dysfunction to present an updated and comprehensive picture of the structural and functional alterations in the central olfactory system as a consequence of olfactory loss and regain. Furthermore, the review also highlights recent progress on optimizing the olfactory functional MRI as well as new approaches for data processing that are promising for future clinical practice.

The Emotional Facet of Subjective and Neural Indices of Similarity Abstract Emotional similarity refers to the tendency to group stimuli together because they evoke the same feelings in us. The majority of research on similarity perception that has been conducted to date has focused on non-emotional stimuli. Different models have been proposed to explain how we represent semantic concepts, and judge the similarity among them. They are supported from behavioural and neural evidence, often combined by using Multivariate Pattern Analyses. By contrast, less is known about the cognitive and neural mechanisms underlying the judgement of similarity between real-life emotional experiences. This review summarizes the major findings, debates and limitations in the semantic similarity literature. They will serve as background to the emotional facet of similarity that will be the focus of this review. A multi-modal and overarching approach, which relates different levels of neuroscientific explanation (i.e., computational, algorithmic and implementation), would be the key to further unveil what makes emotional experiences similar to each other.

Recovering Brain Dynamics During Concurrent tACS-M/EEG: An Overview of Analysis Approaches and Their Methodological and Interpretational Pitfalls Abstract Transcranial alternating current stimulation (tACS) is increasingly used as a tool to non-invasively modulate brain oscillations in a frequency specific manner. A growing body of neuroscience research utilizes tACS to probe causal relationships between neuronal oscillations and cognitive processes or explore its capability of restoring dysfunctional brain oscillations implicated in various neurological and psychiatric disease. However, the underlying mechanisms of action are yet poorly understood. Due to a massive electromagnetic artifact, overlapping with the frequency of interest, direct insights to effects during stimulation from electrophysiological signals (i.e. EEG/MEG) are methodologically challenging. In the current review, we provide an overview of analysis approaches to recover brain signals in M/EEG during tACS, detailing their underlying concepts as well as limitations and methodological and interpretational pitfalls. While different analysis strategies can achieve strong attenuation of the tACS artifact in M/EEG signals, a compete removal of it is not feasible so far. However, we argue that with a combination of careful experimental designs, robust outcome measures and appropriate control analyses, valid and important insights to online effects of tACS can be revealed, enriching our understanding of its basic underlying mechanisms.

“Plis de passage” Deserve a Role in Models of the Cortical Folding Process Abstract Cortical folding is a hallmark of brain topography whose variability across individuals remains a puzzle. In this paper, we call for an effort to improve our understanding of the pli de passage phenomenon, namely annectant gyri buried in the depth of the main sulci. We suggest that plis de passage could become an interesting benchmark for models of the cortical folding process. As an illustration, we speculate on the link between modern biological models of cortical folding and the development of the Pli de Passage Frontal Moyen (PPFM) in the middle of the central sulcus. For this purpose, we have detected nine interrupted central sulci in the Human Connectome Project dataset, which are used to explore the organization of the hand sensorimotor areas in this rare configuration of the PPFM.

The Role of the Temporoparietal Junction in Self-Other Distinction Abstract Being able to discriminate between what originates from ourselves and what originates from others is critical for efficient interactions with our social environment. However, it remains an open question whether self-other distinction is a domain-general mechanism that is involved in various social-cognitive functions or whether specific ‘self-other distinction mechanisms’ exist for each of these functions. On the neural level, there is evidence that self-other distinction is related to a specific brain region at the border of the superior temporal and inferior parietal cortex, the temporoparietal junction (TPJ). Demonstrating that the TPJ plays a role in social processes that require self-other distinction would support the idea of a domain-general mechanism of self-other distinction. In the present paper, we review evidence coming from clinical observations, neuroimaging experiments and a meta-analysis indicating the involvement of the TPJ in various cognitive operations requiring self-other distinction. At the perceptual level, we discuss the human ability to identify one’s own body and to distinguish it from others. At the action level, we review research on the human ability to experience agency and the control of imitative response tendencies. Finally, at the mental-state level, we discuss the ability to attribute mental states to others. Based on this integrative review, we suggest that the TPJ, and in particular its dorsal part, supports a domain general ability to enhance task-relevant representations when self-related and other-related representations are in conflict. Finally, this conception allows us to propose a unifying architecture for the emergence of numerous socio-cognitive abilities.