Project 3

Multimodal assessment of visual function and visual attention

Project 3 aims to:

• Combine transient and steady-state visual evoked potentials for rapid differentiation of schizophrenia patients from controls
• Explore event-related potentials and gamma oscillations underlying the perception of visual form

This project develops and refines new experimental paradigms for assessing the neural basis of sensory processing and attentional mechanisms in the human brain. The primary approach involves non-invasive electrophysiological recordings of EEG and event-related brain activity from the intact scalp, with converging data from fMRI to be obtained in some experiments. This paradigm development and testing is being carried out first in normal subjects with the aim of subsequently applying them to the study of sensory and attentional deficits in schizophrenia patients.

These experiments are closely coordinated with parallel studies in monkeys and in schizophrenia patients carried out by other projects in the Conte Center. More specifically, this project investigates: the role of EEG oscillations of oscillatory hierarchies in selective attention; the neural mechanisms of attention to stimuli that are processed by the magnocellular and parvocellular visual pathways; and the neural mechanisms of attention to multifeature objects composed of high and low spatial frequencies.

These critical processes of selective attention are likely to be disrupted in schizophrenia patients in association with their early sensory deficits and diminished functional brain connectivity. This approach uniquely compares the results of experiments in normal humans with the results of parallel studies in monkeys and in psychiatric patients, which will allow for broader and more incisive interpretations of the emerging data and will permit ongoing design modifications for follow-up studies.

Investigators: Steven Hillyard, PhD (Principal Investigator)