18 to 35 years old
The first visit is to collect information to decide if you can be in the study. After you sign the consent document, you will be asked to answer some questions and complete questionnaires. One of the questionnaires asks for personal information but the completed questionnaire will not be associated with your name or other information that identifies you. During the visit you will be asked about your personality, speech, mood, living situation, medical history, and any past or present drug or alcohol use. We will also ask you about experiences such as hearing voices, seeing visions or having trouble with your thinking. If, during your interview, you are found to have a diagnosable psychiatric disorder, appropriate referrals will be made. If we believe you are eligible to be in the study, we will test your urine to see if you are taking drugs or alcohol. If the drug test screens positive this does not necessarily exclude you from the research, but you may be asked to be re-tested. If you are female, you will be given a urine pregnancy test to determine that you are not pregnant. If you are found to be pregnant you will be not be able to participate in the study. This visit will last about 1 to 2 hours.
During the remaining visits, you will be asked to complete a task that measures your thinking, attention, memory, or concentration, (i.e. a cognitive task) while undergoing transcranial direct current stimulation (tDCS) using an experimental device. You will also participate in functional magnetic resonance imaging (fMRI) or electroencephalogram (EEG) recordings but not both. Whether you participate in fMRI or EEG may depend on the current needs of the study or other factors. For example, you may not be elibigle to participate in fMRI if you have metallic materials in your body and would instead participate in EEG recordings.
Transcranial Direct Current Stimulation tDCS: We will use an experimental device called the Starstim Non-Invasive Wireless tCS Neurostimulator. This device is approved by the U.S. Food & Drug Administration (FDA) but is not approved for the use intended in this study.
To use this device, we will place up to 8 electrodes on your scalp. Electrodes are metal disks to conduct electrical current and are about the size of a silver dollar) Once the electrodes are properly placed, the device will introduce a weak electrical current into your brain through the electrodes. The electrical current is comparable to the output of a 9-volt battery and will be used to stimulate your brain. You will not know when and where the current is being introduced. At some times we may use an inactive or sham stimulation to help us decide if your brain responses are due to the stimulation or if it is due to other causes.
During stimulation you may be asked to sit quietly or do some simple tasks involving looking at a computer screen where you will see figures, symbols, numbers, letters, words or sentences. You will be asked to press a button and tell us what you see on the screen, read aloud, or pick the correct answer to questions such as definitions of words.
You will also be asked to complete a short questionnaire during the stimulation session. This questionnaire will ask about the physical sensations that you are experiencing. You will also be asked to complete the mood questionnaires before and after you complete the stimulation session.
The stimulation procedure will last about 21 minutes and take place prior to fMRI brain scanning or EEG recording. After stimulation we will monitor you to ensure that your mood and physical sensations have returned to normal.
fMRI (Brain Scans): In this study we will also perform magnetic resonance imaging (MRI) of your brain. The MRI machine uses magnetic waves to take pictures inside the body. The waves are not harmful. The MRI scans will occur immediately following the tDCS procedure.
The MRI machine is a large hollow round tube. In an MRI, you will lie comfortably on your back on a table inside the machine while pictures are taken of your brain. The MRI images allow us to see how well your brain functions while you are responding to the computer tasks. You will hear noises during the scan, and wear earplugs so the noises aren’t too loud. You will always be able to talk with the operator or technologist during the study.
You will be asked to perform a task while the MRI recordings are being performed. This task will involve looking at a computer screen where different types of stimuli will be presented. These will be figures, symbols, numbers, letters, words or sentences. You will be asked to respond to these by pressing a button, reading aloud what you see on the screen, or picking from among a group of answers the definition of one of the words.
The MRI portion of the study requires up to 30 minutes for transportation/preparation/debriefing and approximately 1 to 1 and ½ hours in the scanner for a total of 1½ to 2 hours.
Brain Wave Recording (EEG) In this study we will also use EEG to measure brain waves by placing small sensors on your scalp. No stimulation of the scalp is performed during these recording sessions. Several locations on your scalp and face will be cleansed (alcohol may be used) and tin or silver and plastic disks (electrodes) will be attached to those locations with either a sticker or an elastic cap that you will wear.
Between your skin and the electordes, a small amount of electrode jelly will be applied to make good contact. You will sit in a comfortable chair in a small room and will be asked to perform a task. You will be asked to make decisions about what you see or hear and make responses by pressing a button. At the conclusion of the EEG recording, the electrodes will be removed from your scalp and face and the area where the electrodes were located will be cleansed.
Sufficient English literacy so as to be able to understand and complete cognitive tasks.
The ability to give valid informed consent.
Diagnosis of schizophrenia, schizophreniform or schizoaffective disorder (for patient group)
Stable outpatient or partial hospital status (for patient group)
Psychiatric medication changes in the prior month (for patient group)
No psychiatric medication changes anticipated in the upcoming month (for patient group)
Intelligence Quotient (IQ) < 70; IQ will be measured by administering the Wechsler Abbreviated Scale of Intelligence (WASI) test.
People under the age of 18
Implanted brain stimulators
Skin damage or skin conditions such as eczema at the sites where electrodes will be placed
Dreadlocks or other hair styles hindering the placement of tDCS electrodes
Uncorrected vision problems that would hinder cognitive testing (this also pertains to subjects with color blindness in tasks where discriminating colored objects/items is necessary for successful performance).
Other than nicotine, no subjects reporting substance dependence in the past six months and no substance abuse in the past month
Have any questions or want to learn more? Leave your contact details below and the research team will reach out to you.