TMS Enhancement of Visual Plasticity in Schizophrenia

Testing TMS Enhancement of Visual Plasticity in Schizophrenia

The major goal is to determine if Transcranial magnetic stimulation (TMS) enhances visual plasticity in schizophrenia. TMS sessions (sham/placebo and real TMS) will be conducted before two MRI scans with two weeks in-between to assess whether TMS stimulation to the visual cortex will enhance visual plasticity in patients with schizophrenia-spectrum disorders. This project may provide a better understanding of the underlying neurobiological mechanisms responsible for learning and memory deficits in schizophrenia.

Learning and memory impairments are commonly observed in schizophrenia spectrum disorders. Alterations in "long-term potentiation" (LTP), a basic mechanism underlying learning and memory, may explain this impairment. This project will assess fMRI visual plasticity, thought to reflect LTP, in participants with and without schizophrenia spectrum disorders. Previous studies have shown that visual plasticity is impaired in schizophrenia. The major goal is to determine if Transcranial magnetic stimulation (TMS) enhances visual plasticity in schizophrenia. Transcranial magnetic stimulation (TMS) provides a non-invasive means for altering brain electrical neural activity. TMS sessions (sham/placebo and real TMS) will be conducted before two MRI scans with two weeks in-between to assess whether TMS stimulation to the visual cortex will enhance visual plasticity in patients with schizophrenia-spectrum disorders. This project may provide a better understanding of the underlying neurobiological mechanisms responsible for learning and memory deficits in schizophrenia.

Inclusion Criteria:

1. age: 18-65,
2. no neurological illness, head trauma, or major medical illness,
3. not pregnant or nursing,
4. no contraindication for TMS or MRI scanning,
5. no current substance abuse/dependence.

Healthy controls will have no DSM-5 diagnosis and no first-degree relatives with a psychotic disorder.

Inclusion criteria for patients includes:

1. DSM-5 diagnosis of schizophreniform, schizophrenia or schizoaffective and competent to sign an informed consent,
2. not currently taking other medications that affects brain structure (e.g. steroids),
3. less than 12 months antipsychotic exposure and on the same psychotropic medications for 4 weeks prior to study,
4. not be taking clozapine (due to its effects on NMDA receptors and increase of seizure threshold),
5. clinically stable (i.e. no change in psychotic symptoms for at least 4 weeks).

Exclusion Criteria:

1. age outside of 18-65,
2. neurological illness, head trauma, or major medical illness,
3. pregnant or nursing,
4. contraindication for TMS or MRI scanning,
5. current substance abuse/dependence,
6. currently taking medications that affects brain structure (e.g. steroids).

Healthy controls with a DSM-5 diagnosis and/or a first-degree relative with a psychotic disorder. Participants with schizophrenia that are not competent to sign an informed consent, have more than 12 months antipsychotic exposure, not on the same psychotropic medications for 4 weeks prior to study, taking clozapine, and not clinically stable (i.e.a change in psychotic symptoms for at least 4 weeks).