How the human brain generates subjective bodily experience remains a fundamental question in cognitive neuroscience. The cingulate cortex and precuneus (CC/PCu) have been implicated in bodily awareness and self-related processing, yet the functional architecture and causal relevance of these regions and the circuit mechanisms supporting conscious bodily states remain unclear. Here, we combined...
Recent developments in intracranial EEG allow direct recordings from the human thalamus, offering new insight into thalamocortical relationships in the human brain. In this study, we applied direct intracranial electrical stimulation (iES) to the mid-thalamus, within or close to the mediodorsal nucleus, to examine its impact on conscious experience and causal brain connectivity in 30 patients...
Functions of the human insula have been explored extensively with neuroimaging methods and intracranial electrical stimulation studies that have highlighted a functional segregation across its subregions. A recently developed cytoarchitectonic map of the human insula has also segregated this brain region into various areas. Our knowledge of the functional organization of this brain region at...
NeuronAugust 16, 2023Dian Lyu, James Robert Stieger, Cindy Xin et al.
To probe the causal importance of the human posteromedial cortex (PMC) in processing the sense of self, we studied a rare cohort of nine patients with electrodes implanted bilaterally in the precuneus, posterior cingulate, and retrosplenial regions with a combination of neuroimaging, intracranial recordings, and direct cortical stimulations. In all participants, the stimulation of specific...
Significance In this manuscript, we report a rare case of a patient with localized seizures originating from the right anterior and dorsal posteromedial cortex (PMC). We mapped the electrophysiological and neuroimaging connectivity of the ictal onset site and replicated seizure auras by stimulating the homotopical PMC site in the left hemisphere. Our findings provide a causal link between PMC...
NeuronJuly 16, 2021Yitzhak Norman, Omri Raccah, Su Liu et al.
SUMMARY Hippocampal ripples are prominent synchronization events generated by hippocampal neuronal assemblies. To date, ripples have been primarily associated with navigational memory in rodents and shortterm episodic recollections in humans. Here, we uncover different profiles of ripple activity in the human hippocampus during the retrieval of recent and remote autobiographical events and...
BACKGROUND Brain stimulation, both invasive and non-invasive, is increasingly being used to modulate mood and other aspects of subjective experience in various neuropsychiatric conditions. Because this enterprise is deeply dependent on first-person reports provided by patients, sham stimulation is routinely employed to control for demand characteristics and placebo effects. However, a general...
Advanced imaging methods now allow cell-type-specific recording of neural activity across the mammalian brain, potentially enabling the exploration of how brain-wide dynamical patterns give rise to complex behavioural states1–12. Dissociation is an altered behavioural state in which the integrity of experience is disrupted, resulting in reproducible cognitive phenomena including the...
The subjective and behavioral effects of intracranial electrical stimulation (iES) have been studied for decades, but there is a knowledge gap regarding the relationship between the magnitude of electric current and the type, intensity and valence of evoked subjective experiences. We report on rare iES data from 18 neurosurgical patients with implanted intracranial electrodes in the...
NeurologySeptember 19, 2018K. Fox, Jennifer Yih, Omri Raccah et al.
Objective We applied direct cortical stimulation (DCS) to the orbitofrontal cortex (OFC) in neurosurgical patients implanted with intracranial electrodes to probe, with high anatomic precision, the causal link between the OFC and human subjective experience. Methods We administered 272 instances of DCS at 172 OFC sites in 22 patients with intractable focal epilepsy (from 2011 to 2017), none of...
The electrophysiological basis for higher brain activity during rest and internally directed cognition within the human default mode network (DMN) remains largely unknown. Here we use intracranial recordings in the human posteromedial cortex (PMC), a core node within the DMN, during conditions of cued rest, autobiographical judgments, and arithmetic processing. We found a heterogeneous profile...
In this review, we summarize the subjective experiential phenomena and behavioral changes that are caused by electrical stimulation of the cerebral cortex or subcortical nuclei in awake and conscious human subjects. Our comprehensive review contains a detailed summary of the data obtained from electrical brain stimulation (EBS) in humans in the last 100 years. Findings from the EBS studies may...