Crying with depressed affect induced by electrical stimulation of the anterior insula: A stereo EEG case study

Direct stimulation of anterior insula and ventromedial prefrontal cortex disrupts economic choices

Neural activity within the ventromedial prefrontal cortex (vmPFC) and anterior insula (aIns) is often associated with economic choices and confidence. However, it remains unclear whether these brain regions are causally related to these processes. To address this issue, we leveraged intracranial electrical stimulation (iES) data obtained from patients with epilepsy performing an economic choice task. Our results reveal opposite effects of stimulation on decision-making depending on its location along a dorso-ventral axis within each region. Specifically, stimulation of the ventral subregion within aIns reduces risk-taking by increasing participants' sensitivity to potential losses, whereas stimulation of the dorsal subregion of aIns and the ventral portion of the vmPFC increases risk-taking by reducing participants' sensitivity to losses. Moreover, stimulation of the aIns consistently decreases participants' confidence, regardless of its location within the aIns. These findings suggest the existence of functionally dissociated neural subregions and circuits causally involved in accepting or avoiding challenges.

Seizure semiology: ILAE glossary of terms and their significance

This educational topical review and Task Force report aims to address learning objectives of the International League Against Epilepsy (ILAE) curriculum. We sought to extract detailed features involving semiology from video recordings and interpret semiological signs and symptoms that reflect the likely localization for focal seizures in patients with epilepsy. This glossary was developed by a working group of the ILAE Commission on Diagnostic Methods incorporating the EEG Task Force. This paper identifies commonly used terms to describe seizure semiology, provides definitions, signs and symptoms, and summarizes their clinical value in localizing and lateralizing focal seizures based on consensus in the published literature. Video-EEG examples are included to illustrate important features of semiology in patients with epilepsy.