This clinical trial will examine whether transcranial magnetic stimulation (TMS), a noninvasive form of brain stimulation, can influence social cognition, cognitive processing, and brain function in adults with elevated psychopathic traits. The study will also evaluate the safety and feasibility of delivering TMS in this population.

Participants will be randomly assigned to receive either active TMS or sham (placebo-like) TMS. The study will compare outcomes between participants receiving active versus sham TMS and will evaluate changes from before to after TMS exposure.

Participants will:

• Complete a baseline magnetic resonance imaging (MRI) brain scan.
• Receive three single-session TMS interventions.
• Complete a post-intervention MRI brain scan.
• Complete assessments of social cognition.
• Complete assessments of cognitive processing.

The primary objectives are to determine whether TMS can influence social cognition, cognitive processing, and functional brain organization and connectivity in adults with elevated psychopathic traits.

Psychopathic traits are associated with impairments in social cognition, cognitive processing, and alterations in functional brain network organization. Neuroimaging studies have implicated abnormalities in brain regions involved in cognitive control and social information processing, including the right dorsolateral prefrontal cortex (dlPFC) and right temporoparietal junction (TPJ). Transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation technique capable of altering neural activity within targeted brain networks and provides an experimental method for examining the causal contribution of these regions to cognitive and social functioning.

This randomized, sham-controlled clinical trial will evaluate whether theta burst stimulation targeting the right dlPFC or right TPJ influences social cognition, cognitive processing, and functional brain network organization in adults with elevated psychopathic traits. Participants will be randomly assigned to receive inhibitory continuous theta burst stimulation (cTBS) targeting the right dlPFC, excitatory intermittent theta burst stimulation (iTBS) targeting the right TPJ, or sham stimulation. Stimulation targets will be individualized using participant-specific neuroimaging data.

Participants will complete baseline and post-intervention assessments that include functional magnetic resonance imaging (fMRI), measures of social cognition, and measures of cognitive processing. Functional neuroimaging will be used to evaluate changes in brain network organization and connectivity associated with stimulation. Behavioral assessments will evaluate social cognitive processes, including emotion processing and perspective taking, as well as cognitive processes related to attention and cognitive control.

Analyses will compare active stimulation conditions with sham stimulation on measures of social cognition and cognitive processing. Neuroimaging analyses will evaluate both within-subject changes from pre- to post-stimulation and between-group differences in functional brain network organization and connectivity.

The primary objectives are to determine whether theta burst stimulation can influence social cognition, cognitive processing, and functional brain network organization in adults with elevated psychopathic traits and to evaluate the safety and feasibility of delivering TMS in this population. Findings from this study may help clarify the neural mechanisms underlying psychopathic traits and inform future development of targeted neuromodulation interventions.

Inclusion Criteria:

• 18-60 years.
• Elevated psychopathy as defined by the self-report psychopathy scale.
• IQ >= 80.
• No prior diagnosis or current risk of Autism as defined by the autism spectrum quotient.
• Negative urine drug screen.
• At least 7 Days of abstinence from substance use (excluding nicotine)
• Able to provide informed consent.
• No change in psychiatric medication regimen, or medication-free, for 4 weeks before study.
• Adequate English proficiency to complete study procedures and assessments.

Exclusion Criteria:

• Current or lifetime DSM-5 psychotic disorder, schizophrenia, schizoaffective disorder, bipolar disorder, or autism spectrum disorder.
• IQ < 80.
• Clinically significant neurological disorder or medical illness that would make study participation unsafe, including a history of seizures or significant cardiovascular disease.
• Clinically significant abnormality identified on baseline MRI.
• Contraindication to MRI or inability to undergo MRI scanning.
• Current pregnancy or breastfeeding.
• History of head injury resulting in loss of consciousness greater than 15 minutes.
• Diagnosis of dementia.
• Current prescription for benzodiazepines or anticonvulsants.
• Metal implants or non-removable metal objects above the waist.
• Lifetime history of prior clinical treatment with transcranial magnetic stimulation (TMS).
• Serious risk of suicide or homicide.
• Unable or unwilling to comply with study procedures.
• History of intractable migraine.
• Claustrophobia or inability to tolerate enclosed spaces required for MRI procedures.

Upon study completion, neuroimaging and behavioral data will be shared via the brain imaging data sharing database OpenNeuro. Metadata for the study will be included, such as the study protocol.

All publications from this data by the PI or the PI's lab will first preregister the analysis, and all accepted publications will share the analytic code with a link to the GitHub repository in the publication

Participants, TMS technicians administering stimulation, investigators, and outcomes assessors will be masked to intervention assignment. Active and sham stimulation assignments will be implemented using study procedures designed to preserve masking across intervention arms.