Altered Use of Context During Visual Perception in Psychotic Psychopathology: A Neurophysiological Investigation of Tuned and Untuned Suppression During Contrast Perception.

Background And Hypothesis: The human visual system streamlines visual processing by suppressing responses to textures that are similar to their surrounding context. Surround suppression is weaker in individuals with schizophrenia (ISZ); this altered use of visuospatial context may relate to the characteristic visual distortions they experience.

Study Design: To understand atypical surround suppression in psychotic psychopathology, we investigated neurophysiological responses in ISZ, healthy controls (HC), individuals with bipolar disorder (IBP), and first-degree relatives (ISZR/IBPR).

Relational memory function in schizophrenia: Electrophysiological evidence for early perceptual and late associative abnormalities.

We used event-related potentials (ERPs) to examine encoding and retrieval during episodic memory in people with schizophrenia (SZ) and biological relatives of SZ (SZr). To isolate contextual from item-specific aspects of memory, we employed the Relational and Item-Specific Encoding (RISE) task. Twenty two healthy controls (HCs), 22 SZ, and 19 SZr, encoded visual depictions of objects when displayed alone (item-specific) or in pairs (relational encoding), and were later tested on recognition of specific objects and whether pairs of objects had appeared together.

Auditory evoked brain potentials as markers of chronic effects of mild traumatic brain injury in mid-life.

Objective: Auditory event-related potential (ERP) correlates of pre-dementia in late-life may also be sensitive to chronic effects of mild traumatic brain injury (mTBI) in mid-life. In addition to mTBI history, other clinical factors may also influence ERP measures of brain function. This study's objective was to evaluate the relationship between mTBI history, auditory ERP metrics, and common comorbidities.