Executive control of saccades in schizophrenia patients, brain-injured patients, and healthy subjects II


Executive functions encompass several components that contribute to the flexible control of behavior. The project aims at identifying basic control mechanisms and their disruptions in patients with schizophrenia or focal brain lesions of the prefrontal cortex. An impairment of executive control in these patient groups is reliably indicated by increased reflexive saccades in eye movement and fixation tasks. To account for these deficits we developed a model that assumes a competition between stimulus-elicited reflexive saccades and the volitional action that is actually required in the task. It is hypothesized that the initiation of volitional action is impaired in schizophrenia patients, so that reflexive saccades prevail more often in those patients.



In this funding period the model is further validated and specified using a multi-method approach. It is planned to include schizophrenia patients and patients with focal frontal brain lesions in a series of behavioral experiments. In addition, functional magnetic resonance imaging is applied to study the neuronal correlates of volitional and reflexive processes.


Principal Investigators
Kathmann, Norbert Prof. Dr. rer. nat. (Details) (Clinical Psychology)

Duration of Project
Start date: 12/2005
End date: 10/2008

Publications

Franke, C., Arndt, D., Ploner, C.J., Heinz, A., & Reuter, B. (2008). Saccade generation and suppression in schizophrenia: Effects of response switching and perseveration. Psychophysiology, in press.



Ettinger, U., Fftyche, D., Kumari, V., Kathmann, N., Reuter, B., Zelaya, F., Williams, S. (in press). Decomposing the neural correlates of antisaccade eye movements using event-related fMRI. Cerebral Cortex.



Endrass, T., Reuter, B., & Kathmann, N. (in press). ERP correlates of conscious error recognition: Aware and unaware errors in an antisaccade task. European Journal of Neuroscience.



Franke, C., Reuter, B., Schulz, L., & Kathmann, N. (2007). Schizophrenia Patients show Impaired Response Switching in Saccade Tasks. Biological Psychology, 76, 91-99.



Kathmann, N & Reuter, B. (2007). Aufmerksamkeit: Psychologie. In: T. Kircher & S. Gauggel: Neuropsychologie der Schizophrenie. Berlin: Springer.



Reuter, B. & Kathmann, N. (2007). Störungen der Handlungskontrolle im Kontext neuropsychologischer Befunde bei Schizophrenie. Fortschritte der Neurologie-Psychiatrie, 75: 607-616.



Reuter, B., Philipp, M.A., Koch, I., & Kathmann, N. (2006). Effects of switching between leftward and rightward pro- and antisaccades. Biological Psychology, 72, 88-95.


Last updated on 2020-09-03 at 23:10