Studying memory processes at different levels with simultaneous depth and surface EEG recordings.

Investigating cognitive brain functions using non-invasive electrophysiology can be challenging due to the particularities of the task-related EEG activity, the depth of the activated brain areas, and the extent of the networks involved. Stereoelectroencephalographic (SEEG) investigations in patients with drug-resistant epilepsy offer an extraordinary opportunity to validate information derived from non-invasive recordings at macro-scales. The SEEG approach can provide brain activity with high spatial specificity during tasks that target specific cognitive processes (e.

A comparison of uni- and multi-variate methods for identifying brain networks activated by cognitive tasks using intracranial EEG.

Cognitive tasks are commonly used to identify brain networks involved in the underlying cognitive process. However, inferring the brain networks from intracranial EEG data presents several challenges related to the sparse spatial sampling of the brain and the high variability of the EEG trace due to concurrent brain processes. In this manuscript, we use a well-known facial emotion recognition task to compare three different ways of analyzing the contrasts between task conditions: permutation cluster tests, machine learning (ML) classifiers, and a searchlight implementation of multivariate pattern analysis (MVPA) for intracranial sparse data recorded from 13 patients undergoing presurgical evaluation for drug-resistant epilepsy.

Motor and emotional facial features in parietal lobe seizures: an ictal functional connectivity study using SEEG.

Objectives: Parietal lobe epilepsy is one of the rarest types and patients with this form of epilepsy report multiple subjective symptoms during ictal manifestation. Specific facial coupling of emotion and motor symptoms may take various forms, such as pouting and disgust or smiling. We aimed to highlight brain structures and the network involved during ictal grimacing in parietal lobe seizures.

Spontaneous thought and microstate activity modulation by social imitation.

The human mind wanders spontaneously and frequently, revisiting the past and imagining the future of self and of others. External and internal factors can influence wandering spontaneous thoughts, whose content predicts subsequent emotional states. We propose that social imitation, an action that increases well-being and closeness by poorly understood mechanisms, impacts behavioural states in part by modulating post-imitation mind-wandering.

Imaging the effective networks associated with cortical function through intracranial high-frequency stimulation.

Direct electrical stimulation (DES) is considered to be the gold standard for mapping cortical function. A careful mapping of the eloquent cortex is key to successful resective or ablative surgeries, with a minimal postoperative deficit, for treatment of drug-resistant epilepsy. There is accumulating evidence suggesting that not only local, but also remote activations play an equally important role in evoking clinical effects.

Network of autoscopic hallucinations elicited by intracerebral stimulations of periventricular nodular heterotopia: An SEEG study.

Periventricular nodular heterotopias (PVNH) are areas of neurons abnormally located in the white matter that might be involved in physiological cortical functions. Autoscopic hallucinations are changes in self-consciousness determined by a mismatch in integration of multiple sensory inputs. Our goal is to highlight the brain network involved in generation of autoscopic hallucination elicited by electrical stimulation of a PVNH in a drug resistant epilepsy patient.

Extracting seizure onset from surface EEG with independent component analysis: Insights from simultaneous scalp and intracerebral EEG.

The success of stereoelectroencephalographic (SEEG) investigations depends crucially on the hypotheses on the putative location of the seizure onset zone. This information is derived from non-invasive data either based on visual analysis or advanced source localization algorithms. While source localization applied to interictal spikes recorded on scalp is the classical method, it does not provide unequivocal information regarding the seizure onset zone.

Accuracy and Safety of Customized Stereotactic Fixtures for Stereoelectroencephalography in Pediatric Patients.

Stereoelectroencephalography (SEEG) in children with intractable epilepsy presents particular challenges. Their thin and partially ossified cranium, specifically in the temporal area, is prone to fracture while attaching stereotactic systems to the head or stabilizing the head in robot's field of action. Postponing SEEG in this special population of patients can have serious consequences, reducing their chances of becoming seizure-free and impacting their social and cognitive development.

Social Feedback During Sensorimotor Synchronization Changes Salivary Oxytocin and Behavioral States.

In humans and animal models, oxytocin increases social closeness, attachment and prosocial behaviors, while decreasing anxiety and stress levels. Efficiently triggering the release of endogenous oxytocin could serve as a powerful therapeutic intervention for disorders of social behavior and for anxiety. We designed a new version of a social sensorimotor synchronization task to investigate the role of social approval in inducing biochemical and psychological changes following behavioral synchrony in a sample of 80 college students.

Cingulate cortex function and multi-modal connectivity mapped using intracranial stimulation.

The cingulate cortex is part of the limbic system. Its function and connectivity are organized in a rostro-caudal and ventral-dorsal manner which was addressed by various other studies using rather coarse cortical parcellations. In this study, we aim at describing its function and connectivity using invasive recordings from patients explored for focal drug-resistant epilepsy.

Clinical Accuracy of Customized Stereotactic Fixtures for Stereoelectroencephalography.

Background: Stereoelectroencephalograpy (SEEG) is a diagnostic method involving 3-dimensional exploration of brain structures using depth electrodes for locating epileptogenic foci in patients with drug-resistant epilepsy. A variety of frame-based, frameless, and robotic stereotactic systems have been designed for the accurate placement of depth electrodes.

Objectives: Using the FHC microTargeting platform as a model, we introduce a fully customized design that has all the constructive elements positioned by a computer algorithm, according to the planned trajectories, anchoring points, and anatomic constraints.

Encoded multichromophore response for simultaneous label-free detection.

The self-assembly of molecularly precise nanostructures is widely expected to form the basis of future high-speed integrated circuits, but the technologies suitable for such circuits are not well understood. In this work, DNA self-assembly is used to create molecular logic circuits that can selectively identify specific biomolecules in solution by encoding the optical response of near-field coupled arrangements of chromophores. The resulting circuits can detect label-free, femtomole quantities of multiple proteins, DNA oligomers, and small fragments of RNA in solution via ensemble optical measurements.