Temporal Interference Stimulation for Social Cognition (TISSC)

Transcranial interference stimulation (tIS) has been used outside of the United States (US) but not previously under Food and Drug Administration (FDA) regulation. This represents the first in human use of tIS in the US. tIS may be useful in the treatment of social cognitive impairments in schizophrenia and especially in the reversal of oscillatory dysfunction of the pulvinar nucleus of the thalamus. The overall project will investigate the safety and tolerability of tIS first in healthy volunteers and then in individuals with schizophrenia. This protocol is for stage 1a of the overall project only. In this stage, safety and tolerability will be assessed along with initial evaluation of target engagement. This stage uses a single ascending dose design with 10 participants per dose at each of three doses.

The stage 1a involves 30 healthy individuals and employs advanced techniques such as simultaneous electroencephalogram (EEG)/tIS, functional magnetic resonance imaging (fMRI), and magnetic resonance spectroscopy (MRS) to investigate the spatio-temporal dynamics of face emotion processing. These methods help us pinpoint specific brain regions like the pulvinar nucleus of the thalamus (PuN) and assess the safety and potential therapeutic benefits of tIS. Participants initially undergo an MRI session to localize their individual pulvinar nucleus of the thalamus (PuN). This step allows the investigators to model transcranial current flow accurately and precisely target the PuN using tIS. Subsequently, participants engage in simultaneous EEG recordings and tIS, which falls under the umbrella of transcranial electrical stimulation (tES). The timing of these sessions, whether single or repeated, depends on the study stage. The investigators also assess brain metabolism effects through MRS before and after tIS stimulation. Participants will go through several steps: 1) Interviews to determine eligibility 2) Behavioral tests of their ability to detect and interpret visual stimuli 3) "Brain wave" recordings or electroencephalogram 4) A non-invasive brain stimulation technique termed transcranial interference stimulation 5) Magnetic resonance imaging (MRI). Participants will also have an electrocardiogram and medical examination to evaluate their general health.