The perspectives of mapping and monitoring of the sense of self in neurosurgical patients

Self-other voice discrimination task: A potential neuropsychological tool for clinical assessment of self-related deficits

Background

Deficits in self are commonly described through different neuro-pathologies, based on clinical evaluations and experimental paradigms. However, currently available approaches lack appropriate clinical validation, making objective evaluation and discrimination of self-related deficits challenging.

Methods

We applied a statistical standardized method to assess the clinical discriminatory capacity of a Self-Other Voice Discrimination (SOVD) task. This task, validated experimentally as a marker for self-related deficits, was administered to 17 patients eligible for neurosurgery due to focal hemispheric brain tumors or epileptic lesions.

Results

The clinical discriminatory capacity of the SOVD task was evident in three patients who exhibited impairments for self-voice perception that could not be predicted by other neuropsychological deficits. Impairments in other-voice perception were linked to inhibitory neuropsychological deficits, suggesting a potential association with executive deficits in voice recognition.

Conclusions

This exploratory study highlights the clinical discriminatory potential of the SOVD task and suggests that it could complement the standard neuropsychological assessment, paving the way for enhanced diagnoses and tailored treatments for self-related deficits.

Meeting the multidimensional self: fostering selfhood at the interface of Creative Arts Therapies and neuroscience

Intriguing explorations at the intersection of the fields of neuroscience and psychology are driven by the quest to understand the neural underpinnings of "the self" and their psychotherapeutic implications. These translational efforts pertain to the unique Creative Arts Therapies (CATs) and the attributes and value of the self-related processes they offer. The self is considered as a multi-layered complex construct, comprising bodily and mental constituents, subjective-objective perspectives, spatial and temporal dimensions. Neuroscience research, mostly functional brain imaging, has proposed cogent models of the constitution, development and experience of the self, elucidating how the multiple dimensions of the self are supported by integrated hierarchical brain processes. The psychotherapeutic use of the art-forms, generating aesthetic experiences and creative processes, touch upon and connect the various layers of self-experience, nurturing the sense of self. The present conceptual analysis will describe and interweave the neural mechanisms and neural network configuration suggested to lie at the core of the ongoing self-experience, its deviations in psychopathology, and implications regarding the psychotherapeutic use of the arts. The well-established, parsimonious and neurobiologically plausible predictive processing account of brain-function will be discussed with regard to selfhood and consciousness. The epistemic affordance of the experiential CATs will further be portrayed, enabling and facilitating the creation of updated self-models of the body in the world. The neuropsychological impact of the relational therapeutic encounter will be delineated, acknowledging the intersubjective brain synchronization through communicative verbal and non-verbal means and aesthetic experiences. The recognition and assimilation of neuroscientific, phenomenological and clinical perspectives concerning the nested dimensionality of the self, ground the relational therapeutic process and the neuroplastic modulations that CATs have to offer on the premise of fostering, shaping and integrating selfhood.

Individual Differences in Bodily Self-Consciousness and Its Neural Basis

Bodily self-consciousness (BSC), a subject of interdisciplinary interest, refers to the awareness of one's bodily states. Previous studies have noted the existence of individual differences in BSC, while neglecting the underlying factors and neural basis of such individual differences. Considering that BSC relied on integration from both internal and external self-relevant information, we here review previous findings on individual differences in BSC through a three-level-self model, which includes interoceptive, exteroceptive, and mental self-processing. The data show that cross-level factors influenced individual differences in BSC, involving internal bodily signal perceptibility, multisensory processing principles, personal traits shaped by environment, and interaction modes that integrate multiple levels of self-processing. Furthermore, in interoceptive processing, regions like the anterior cingulate cortex and insula show correlations with different perceptions of internal sensations. For exteroception, the parietal lobe integrates sensory inputs, coordinating various BSC responses. Mental self-processing modulates differences in BSC through areas like the medial prefrontal cortex. For interactions between multiple levels of self-processing, regions like the intraparietal sulcus involve individual differences in BSC. We propose that diverse experiences of BSC can be attributed to different levels of self-processing, which moderates one's perception of their body. Overall, considering individual differences in BSC is worth amalgamating diverse methodologies for the diagnosis and treatment of some diseases.

What is the Philosophy of Neurosurgery? Systematic Review and Defining the Discipline

INTRODUCTION

Despite centuries of joint investigation of philosophy and neurological interventions, a founding account for the philosophy of neurosurgery has yet to be rigorously constructed or defended. This paper reviews recent work on the philosophy of neurosurgery, spanning metaphysics, epistemology, and value theory, to establish a framework and clinical relevance for study in the philosophy of neurosurgery.

METHODS

A systematic review of an online database was conducted using the broad search terms, "Philosophy AND (Neurosurgery OR Neurological Surgery)." Records were included if they demonstrated relevance to the philosophy of neurosurgery and analytical rigor, but were excluded if solely legal, clinical, or ethical principles were considered without substantive discussion of underlying ethical frameworks and philosophical principles.

RESULTS

Of 8025 candidates from online and print records, 16 records (14 from online sources and 2 from an edited volume) met inclusion criteria for the systematic review. Three dealt with metaphysics, 3 dealt with epistemology, 4 dealt with value theory, 5 dealt with metaphysics/epistemology, and 1 dealt with value theory/metaphysics. Questions of free will, consciousness, personal identity, neurosurgical knowledge, ascription of other minds, deontology, and minimalism, among others, were considered.

DISCUSSION

Based on identified studies, the philosophy of neurosurgery is defined as the discipline of rigorously and methodically addressing metaphysical, epistemological, and value-theoretic questions arising from physically intervening in the nervous system. We discuss future directions for questions within the philosophy of neurosurgery and consider their relevance for patient care and the practice of neurosurgery.

Experimentally-evidenced personality alterations following meningioma resection: A case report

Personality changes following neurosurgical procedures remain poorly understood and pose a major concern for patients, rendering a strong need for predictive biomarkers. Here we report a case of a female patient in her 40s who underwent resection of a large sagittal sinus meningioma with bilateral extension, including resection and ligation of the superior sagittal sinus, that resulted in borderline personality disorder. Importantly, we captured clinically-observed personality changes in a series of experiments assessing self-other voice discrimination, one of the experimental markers for self-consciousness. In all experiments, the patient consistently confused self- and other voices - i.e., she misattributed other-voice stimuli to herself and self-voice stimuli to others. Moreover, the electroencephalogram (EEG) microstate, that was in healthy participants observed when hearing their own voice, in this patient occurred for other-voice stimuli. We hypothesize that the patient's personality alterations resulted from a gradual development of a venous collateral hemodynamic network that impacted venous drainage of brain areas associated with self-consciousness. In addition, resection and ligation of the superior sagittal sinus significantly aggravated personality alterations through postoperative decompensation of a direct frontal lobe compression. Experimentally mirroring clinical observations, these findings are of high relevance for developing biomarkers of post-surgical personality alterations.

Understanding the neural bases of bodily self-consciousness: recent achievements and main challenges

The last two decades have seen a surge of interest in the mechanisms underpinning bodily self-consciousness (BSC). Studies showed that BSC relies on several bodily experiences (i.e., self-location, body ownership, agency, first-person perspective) and multisensory integration. The aim of this literature review is to summarize new insights and novel developments into the understanding of the neural bases of BSC, such as the contribution of the interoceptive signals to the neural mechanisms of BSC, and the overlap with the neural bases of conscious experience in general and of higher-level forms of self (i.e., the cognitive self). We also identify the main challenges and propose future perspectives that need to be conducted to progress into the understanding of the neural mechanisms of BSC. In particular, we point the lack of crosstalk and cross-fertilization between subdisciplines of integrative neuroscience to better understand BSC, especially the lack of research in animal models to decipher the neural networks and systems of neurotransmitters underpinning BSC. We highlight the need for more causal evidence that specific brain areas are instrumental in generating BSC and the need for studies tapping into interindividual differences in the phenomenal experience of BSC and their underlying mechanisms.

Breathing control, brain, and bodily self-consciousness: Toward immersive digiceuticals to alleviate respiratory suffering

Breathing is peculiar among autonomic functions through several characteristics. It generates a very rich afferent traffic from an array of structures belonging to the respiratory system to various areas of the brain. It is intimately associated with bodily movements. It bears particular relationships with consciousness as its efferent motor control can be automatic or voluntary. In this review within the scope of "respiratory neurophysiology" or "respiratory neuroscience", we describe the physiological organisation of breathing control. We then review findings linking breathing and bodily self-consciousness through respiratory manipulations using virtual reality (VR). After discussing the currently admitted neurophysiological model for dyspnea, as well as a new Bayesian model applied to breathing control, we propose that visuo-respiratory paradigms -as developed in cognitive neuroscience- will foster insights into some of the basic mechanisms of the human respiratory system and will also lead to the development of immersive VR-based digital health tools (i.e. digiceuticals).

Clinical considerations on a right operculo-insular cavernous angioma: an illustrative case

The insular cortex is considered one of the most complex regions of the brain, defined as the "hub" of somatosensory areas. Here, we examine the case of a surgically treated haemorrhagic cavernoma involving the middle and posterior insular cortex, presenting both sensory, gustative and speech symptoms. By reviewing the recent findings in humans' and primates' basic research, we illustrated clinical and radiological correlations of the reported case, confirming insular role in sensitive and gustatory functions.

Augmented reality-assisted roadmaps during periventricular brain surgery

Visualizing major periventricular anatomical landmarks intraoperatively during brain tumor removal is a decisive measure toward preserving such structures and thus the patient's postoperative quality of life. The aim of this study was to describe potential standardized preoperative planning using standard landmarks and procedures and to demonstrate the feasibility of using augmented reality (AR) to assist in performing surgery according to these "roadmaps." The authors have depicted stepwise AR surgical roadmaps applied to periventricular brain surgery with the aim of preserving major cognitive function. In addition to the technological aspects, this study highlights the importance of using emerging technologies as potential tools to integrate information and to identify and visualize landmarks to be used during tumor removal.

Anatomical aspects of the insula, opercula and peri-insular white matter for a transcortical approach to insular glioma resection

The insula is a lobe located deep in each hemisphere of the brain and is surrounded by eloquent cortical, white matter, and basal ganglia structures. The aim of this study was to provide an anatomical description of the insula and white matter tracts related to surgical treatment of gliomas through a transcortical approach. The study also discusses surgical implications in terms of intraoperative brain mapping. Five adult brains were prepared according to the Klingler technique. Cortical anatomy was evaluated with the naked eye, whereas white matter dissection was performed with the use of a microscope. The widest exposure of the insular surface was noted through the temporal operculum, mainly in zones III and IV according to the Berger-Sanai classification. By going through the pars triangularis in all cases, the anterior insular point and most of zone I were exposed. The narrowest and deepest operating field was observed by going through the parietal operculum. This method provided a suitable approach to zone II, where the corticospinal tract is not covered by the basal ganglia and is exposed just under the superior limiting sulcus. At the subcortical level, the identification of the inferior frontoocipital fasciculus at the level of the limen insulae is critical in terms of preserving the lenticulostriate arteries. Detailed knowledge of the anatomy of the insula and subcortical white matter that is exposed through each operculum is essential in preoperative planning as well as in the intraoperative decision-making process in terms of intraoperative brain mapping.