Prefrontal-subthalamic theta signaling mediates delayed responses during conflict processing.

While medial frontal cortex (MFC) and subthalamic nucleus (STN) have been implicated in conflict monitoring and action inhibition, respectively, an integrated understanding of the spatiotemporal and spectral interaction of these nodes and how they interact with motor cortex (M1) to definitively modify motor behavior during conflict is lacking. We recorded neural signals intracranially across presupplementary motor area (preSMA), M1, STN, and globus pallidus internus (GPi), during a flanker task in 20 patients undergoing deep brain stimulation implantation surgery for Parkinson disease or dystonia. Conflict is associated with sequential and causal increases in local theta power from preSMA to STN to M1 with movement delays directly correlated with increased STN theta power, indicating preSMA is the MFC locus that monitors conflict and signals STN to implement a 'break.' Transmission of theta from STN-to-M1 subsequently results in a transient increase in M1-to-GPi beta flow immediately prior to movement, modulating the motor network to actuate the conflict-related action inhibition (i.e., delayed response). Action regulation during conflict relies on two distinct circuits, the conflict-related theta and movement-related beta networks, that are separated spatially, spectrally, and temporally, but which interact dynamically to mediate motor performance, highlighting complex parallel yet interacting networks regulating movement.

Disentangling Function from Benefit: Participant Perspectives from an Early Feasibility Trial for a Novel Visual Cortical Prosthesis.

Visual cortical prostheses (VCPs) have the potential to provide artificial vision for visually impaired persons. However, the nature and utility of this form of vision is not yet fully understood. Participants in the early feasibility trial for the Orion VCP were interviewed to gain insight into their experiences using artificial vision, their motivations for participation, as well as their expectations and assessments of risks and benefits. Analyzed using principles of grounded theory and an interpretive description approach, these interviews yielded six themes, including: the irreducibility of benefit to device functionality, mixed expectations for short-term device functionality and long-term technological advancement of visual prostheses, and a broad range of risks, concerns, and fears related to trial participation. We argue that these narratives motivate a nuanced set of ethical considerations related to the complex relationship between functionality and benefit, the intersection of user experience with disability justice, and the import of expectations and indirect risks on consent.

"They were already inside my head to begin with": Trust, Translational Misconception, and Intraoperative Brain Research.

Background: Patients undergoing invasive neurosurgical procedures offer researchers unique opportunities to study the brain. Deep brain stimulation patients, for example, may participate in research during the surgical implantation of the stimulator device. Although this research raises many ethical concerns, little attention has been paid to basic studies, which offer no therapeutic benefits, and the value of patient-participant perspectives.Methods: Semi-structured interviews were conducted with fourteen individuals across two studies who participated in basic intraoperative research during their deep brain stimulator surgery. Interviews explored interpretations of risks and benefits, enrollment motivations, and experiences of participating in awake brain research. Reflexive thematic analysis was conducted.Results: Seven themes were identified from participant narratives, including robust attitudes of trust, high valuations of basic science research, impacts of the surgical context, and mixed experiences of participation.Conclusion: We argue that these narratives raise the potential for a translational misconception and motivate intraoperative re-consent procedures.

Ethical commitments, principles, and practices guiding intracranial neuroscientific research in humans.

Leveraging firsthand experience, BRAIN-funded investigators conducting intracranial human neuroscience research propose two fundamental ethical commitments: (1) maintaining the integrity of clinical care and (2) ensuring voluntariness. Principles, practices, and uncertainties related to these commitments are offered for future investigation.