Intrinsic and Novelty-related Sensory Cortical Disinhibition and Sensory-Prefrontal-Cortex-Amygdala Pathology in Posttraumatic Stress Disorder (PTSD) Using Transcranial Alternating Current Stimulation (tACS) and Transcranial Random Noise Stimulation (tRNS)

What this Trial Is About

Researchers are investigating the brain mechanisms behind Posttraumatic Stress Disorder (PTSD), focusing on how abnormal activity in sensory and brain regions relates to symptoms like anxiety and hypervigilance. The study aims to test a new model linking sensory cortex, prefrontal cortex, and amygdala dysfunctions to better understand PTSD's underlying causes. It also evaluates how a brain stimulation technique called Transcranial Alternating Current Stimulation (tACS) may influence these brain networks and emotional responses. Participants will be randomly assigned to one of three groups: active tACS at their individual alpha frequency, a sham (placebo) tACS where no current is passed, or an active control using Transcranial Random Noise Stimulation (tRNS). Each stimulation involves placing electrodes on the scalp within an EEG cap and delivering a weak electrical current for 10 to 40 minutes. The study includes two experiments using simultaneous EEG and functional MRI scans, taken before and after stimulation during rest and a novelty detection task. During the study, participants will undergo brain imaging and EEG recordings to measure changes in brain activity and responses related to attention and vigilance. These include monitoring EEG alpha power, fMRI blood flow signals, performance on an oddball detection task, and skin conductance. The researchers will compare these measures before and immediately after stimulation to assess the effects. Participant involvement lasts during the study sessions, and the safety and effects of the brain stimulation are closely monitored throughout the process.

A Neurosensory Account of Anxiety and Stress (Study 1)