Gamma phase synchrony during face processing in schizophrenia

Proposal details

Title: Gamma phase synchrony during face processing in schizophrenia
Research Area(s): Schizophrenia and Allied Psychoses
Background: Face perception has been shown to induce gamma phase synchrony in humans, with the onset being linked to conscious perception of the face. Schizophrenia has been characterized by abnormalities in producing gamma phase synchrony. In this study, we will compare a normative sample, and a schizophrenia sample on gamma phase synchrony during trials in which neutral faces are perceived and not perceived.
Aims: The primary specific aim of the proposed data analyses is to determine whether schizophrenia patients demonstrate reduced gamma phase synchrony during face perception, compared to nonpatient controls. A related, second aim, is to determine the difference between induced gamma for consciously perceived versus sub-consciously perceived faces, and to examine whether this difference differs in magnitude between the two groups. A third aim is to determine whether this abnormality, if found, is associated with clinical disorganization (i.e., disorganized symptoms such as thought disorder), as we have hypothesized in prior work. Our hypothesis is that schizophrenia patients will demonstrate reductions in gamma phase synchrony during conscious face perception, and that this will be significantly correlated with disorganized symptoms.
Method: Gamma phase synchrony indices from the Conscious and Subconscious Processing of Facial Emotions Task, separated by correct and incorrect trials, for conscious and subconscious faces, will be compared between the two groups. Only neutral emotion faces will be used for this project. The window of data that is most critical is in the first 200 msec. after stimulus onset, corresponding with conscious perception in trials from that category. Disorganization will be assessed using data from the PANSS Cognitive Factor, which includes the items Poor Attention, Conceptual Disorganization, Mannerisms and Posturing, Abstract Reasing Difficulties, and Disorientation.