Brain Imaging, Attention, and Auditory Processing in Schizophrenia

Predictive Coding Abnormalities in Psychosis: EEG and fMRI

This is a research study designed to examine how the psychiatric illness called schizophrenia affects brain function and thinking abilities such as attention and memory during simple computer-based tasks, and how measures of brain function are related to performance. The investigators do this by looking at brain activity using electroencephalography (EEG) and magnetic resonance imaging (MRI). The investigators compare participants' results to the activity in their brain as well as clinical measures and questionnaires also completed during this study.

• EEG recording: In this procedure, the researcher will assess the participant's brain function while performing simple computer-based tasks. The computer tasks involve presentation of pictures or sounds to which the participant responds by pressing a button. The investigators will also record some of the participant's own speech sounds and play them back to them. The participant will be given clear instructions and a chance to practice before each task. While you are performing these tasks, the investigator will record the weak electrical signals produced by your brain, or "brain waves", using a technique called electroencephalography (EEG). In order to record the participant's EEG, sensors (small plastic discs) will be attached to specific locations on their scalp. The participant's scalp will be gently scrubbed before the sensors are attached. The sensors are held in place on the scalp using a nylon cap that fits snugly on the head. Sensors will also be attached above and below the participant's eyes and will record their eye movements. It will take approximately one hour to attach the sensors. The entire EEG will take approximately 2-3 hours. Before taking part in the EEG session, please make sure to wash hair and scalp. Do not use conditioner or a 2-in-1 shampoo/conditioner. The participant's hair should be dry before arrival. The investigators ask this in order to make the set-up process go more smoothly.

  • During some tasks, participants will feel a vibratory sensation that is produced with an electrical current and it is possible that it may feel like a slight shock. The current is controlled and cannot reach levels that are painful or dangerous. Every participant experiences this sensation differently, so it is important that participants tell the researchers if the sensation becomes uncomfortable to you so the current can be adjusted or the task can be stopped.
  • Participants may be asked to complete additional EEGs for this study, depending on your interest in participating and your availability. All EEG sessions will last approximately 2 hrs.

• MRI: In the fMRI procedure, we will use a magnet to measure blood flow to participants' brains while they do different tasks. Participants will be asked to lie down on a platform that can be slid into the middle of the magnet. A plastic MRI imaging coil will be placed around participants' heads. You will not come into contact with the coil during the experiment. Foam pads will be placed around the participant's head to limit head movement during the experiment. The investigators will then slide you into the magnet. At different points during the experiment, participants will be asked to do the same tasks they did in the training session prior to the scan. During the scan, participants will be asked to either lie still and rest, or do some tasks like tapping their fingers, remembering letters or digits, or viewing images that are designed to activate different parts of the brain. The entire MRI will take approximately two hours.

  • While performing the MRI, participants may be asked to wear a cap that contains multiple EEG sensors applied to your scalp. A removable gel will be used. The EEG measures electrical activity produced by the brain while participants undergo the MRI. Set up for the EEG will take approximately 30 to 60 minutes.
  • Participants may be asked to repeat an MRI session if the data the study team collects is not usable due to data quality issues, or if the participant is unable to stay awake in the magnet during your scan.

• Brief interview session: There will be a series of questions about participants' education, smoking status, and economic background. Participants will also be given a list of words to read to the researcher. If the participant is a patient diagnosed with one of the above-mentioned psychiatric disorders, they will be asked to participate in an additional interview, lasting about one hour, focusing on how they have been feeling recently.

• Behavioral testing: In this part, the participant will use a touch screen computer, mouse and/or paper and pencil to perform certain visual and auditory tests of your mental abilities. Specifically, these tests will assess participants' memory, attention, language, and motor skills. This testing will last approximately one hour. Depending on the participant's preference, this testing can be done on the same day as an EEG or on a different day. The order of the two sessions does not matter, so long as they occur within one week of each other.

Additional Information:

• If information about a participant's mental health is needed from their current or former doctor(s), they will be asked to sign a separate permission form before the researcher can contact their doctor(s).

Inclusion Criteria:

• The subject population will include 18 to 75 year old participants of any gender, race, and ethnicity. All subjects will be able to speak and understand English.

Schizophrenia subjects:

1. Patients must be diagnosed with DSM-IV schizophrenia, schizophreniform, or schizoaffective disorder based on a SCID-P interview.

Comparison subjects:

1. Control participants must not have past or present Axis I diagnosis as determined by the SCID-NP.

Exclusion Criteria:

• All subjects:

  1. A hearing deficit greater than 40dB in both ears detected during the hearing test
  2. Substance dependence, as per clinical judgment, in the past 1 year (except caffeine and nicotine)
  3. A history of significant medical/neurological disease such as cardiac, thyroid, renal, hepatic or neurological
  4. History of head injury with loss of consciousness greater than 15 minutes
  5. Any other condition or medication, which in the opinion of the investigator would preclude participation in the study.
  6. Non-English speaking.

Comparison subjects:

1. Any first-degree relative with schizophrenia or bipolar disorder.