Sonia Bansal1, Laurence C Jayet Bray2, Barbara L Schwartz3, Wilsaan M Joiner4. 1. Department of Neuroscience, George Mason University, Fairfax, Virginia; Mental Health Service Line, Washington DC Veterans Affairs Medical Center, Washington, DC. 2. Department of Bioengineering, George Mason University, Fairfax, Virginia. 3. Mental Health Service Line, Washington DC Veterans Affairs Medical Center, Washington, DC; Department of Psychiatry, Georgetown University School of Medicine, Washington, DC. 4. Department of Neuroscience, George Mason University, Fairfax, Virginia; Department of Bioengineering, George Mason University, Fairfax, Virginia; Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia. Electronic address: wjoiner2@gmu.edu.
Abstract
BACKGROUND: Symptoms of psychosis in schizophrenia reflect disturbances in sense of agency-difficulty distinguishing internally from externally generated sensory and perceptual experiences. One theory attributes these anomalies to a disruption in corollary discharge (CD), an internal copy of generated motor commands used to distinguish self-movement-generated sensations from externally generated stimulation. METHODS: We used a transsaccadic shift detection paradigm to examine possible deficits in CD and sense of agency based on the ability to perceive visual changes in 31 schizophrenia patients (SZPs) and 31 healthy control subjects. We derived perceptual measures based on manual responses indicating the transsaccadic target shift direction. We also developed a distance-from-unity-line measure to quantify use of CD versus purely sensory (visual) information in evaluating visual changes in the environment after an eye movement. RESULTS: SZPs had higher perceptual thresholds in detecting shift of target location than healthy control subjects, regardless of movement direction or amplitude. Despite producing similar hypometric saccades, healthy control subjects overestimated target location, whereas SZPs relied more on the experienced visual error and consequently underestimated the target position. We show that in SZPs the postsaccadic judgment of the initial target location was largely aligned with the measure based only on visual error, suggesting a deficit in the use of CD. This CD deficit also correlated with positive schizophrenia symptoms and disturbances in sense of agency. CONCLUSIONS: These results provide a novel approach in quantifying abnormal use of CD in SZPs and provide a framework to distinguish deficits in sensory processing versus defects in the internal CD-based monitoring of movement.
BACKGROUND: Symptoms of psychosis in schizophrenia reflect disturbances in sense of agency-difficulty distinguishing internally from externally generated sensory and perceptual experiences. One theory attributes these anomalies to a disruption in corollary discharge (CD), an internal copy of generated motor commands used to distinguish self-movement-generated sensations from externally generated stimulation. METHODS: We used a transsaccadic shift detection paradigm to examine possible deficits in CD and sense of agency based on the ability to perceive visual changes in 31 schizophreniapatients (SZPs) and 31 healthy control subjects. We derived perceptual measures based on manual responses indicating the transsaccadic target shift direction. We also developed a distance-from-unity-line measure to quantify use of CD versus purely sensory (visual) information in evaluating visual changes in the environment after an eye movement. RESULTS: SZPs had higher perceptual thresholds in detecting shift of target location than healthy control subjects, regardless of movement direction or amplitude. Despite producing similar hypometric saccades, healthy control subjects overestimated target location, whereas SZPs relied more on the experienced visual error and consequently underestimated the target position. We show that in SZPs the postsaccadic judgment of the initial target location was largely aligned with the measure based only on visual error, suggesting a deficit in the use of CD. This CD deficit also correlated with positive schizophrenia symptoms and disturbances in sense of agency. CONCLUSIONS: These results provide a novel approach in quantifying abnormal use of CD in SZPs and provide a framework to distinguish deficits in sensory processing versus defects in the internal CD-based monitoring of movement.
Authors: Beier Yao; Sebastiaan F W Neggers; Martin Rolfs; Lara Rösler; Ilse A Thompson; Helene J Hopman; Livon Ghermezi; René S Kahn; Katharine N Thakkar Journal: J Neurosci Date: 2019-01-10 Impact factor: 6.167
Authors: Beier Yao; Martin Rolfs; Christopher McLaughlin; Emily L Isenstein; Sylvia B Guillory; Hannah Grosman; Deborah A Kashy; Jennifer H Foss-Feig; Katharine N Thakkar Journal: J Vis Date: 2021-08-02 Impact factor: 2.240