Visual Perception in Schizophrenia

Visual Perception in Schizophrenia: Assessing Predictive Processing in the Earliest Stages of the Visual Cortical Hierarchy

This study aims to identify novel markers of psychosis using electroencephalography (EEG).

Inclusion Criteria:

• All Subjects
• Aged 18-65
• 20/32 visual acuity or better (using in-house optical correction, if necessary)
• An ability to speak English well enough to complete study assessments and to consent to the study
• Subjects with Schizophrenia-Spectrum Disorder
• Meets DSM-5 diagnostic criteria for schizophrenia, schizoaffective disorder, or schizophreniform disorder as confirmed by the Structured Interview for DSM-5 (SCID-5).
• Subjects with Bipolar Disorder
• Meets DSM-5 diagnostic criteria for bipolar disorder (type I, II, or unspecified) as confirmed by the Structured Interview for DSM-5 (SCID-5).

Exclusion Criteria:

• All subjects

• Presence of characteristics that could impair one's ability to comprehend the nature of the study, provide informed consent, or understand the assessment questions, including the following:

  • Subject cannot read and understand the instructions well enough to complete the tasks or cannot provide informed consent.
  • Intellectual impairment (WRAT-5 score < 70) (at the discretion of experimenter);
  • Actively intoxicated, as shown via patient self-report or staff report;
  • Substance use disorder in the past 3 months;
  • Subject considered high risk for suicidal acts (i.e., active suicidal ideation as determined by clinical interview OR any suicide attempt in 30 days prior to screening);
  • Subject violence (involving severe/lethal means or violence occurring in prior 6 months) or extreme agitation.
  • Being in a current manic state
  • Head injury with loss of consciousness greater than 10 minutes (at the discretion of the experimenter).
  • Subject has had electroconvulsive therapy (ECT) in the past 8 weeks;
  • Diagnosed with a neurological condition (tumor, stroke, brain injury) or neurological disorder, including seizure disorders. Diagnosed with pervasive developmental disorder (phone screen or medical records)
  • Lazy eye or squint or other known ocular pathology

• Healthy Control Subjects

• Any lifetime psychotic disorder or history of psychiatric hospitalization (self disclosure);

• Daily antidepressant, mood stabilizer or antipsychotic medication use in the last 6 months, or benzodiazepine use during the prior 2 days (self-disclosure); iii. First-degree relative(s) with a schizophrenia spectrum disorder (based on subject self-report) or bipolar disorder.

• Case-match Control Non-ill Subjects

• Any lifetime psychotic disorder (as assessed by SCID/or SSD);

• Recurrent depressive episodes or being in a current depressive episode (as assessed by SCID/or SSD)

• Persistent threshold psychotic symptoms

• History of psychiatric hospitalization;

• Daily antidepressant, mood stabilizer or antipsychotic medication use in the last 6 months, or benzodiazepine use during the prior 2 days

• First-degree relative(s) with a schizophrenia spectrum disorder (based on subject self-report) or bipolar disorder.

• Bipolar Subjects

• Persistent threshold psychotic symptoms