Related Experiment Video
Updated: Apr 11, 2026

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis
Published on: November 21, 2013
Theta response in schizophrenia is indifferent to perceptual illusion
Birgit Mathes1, Christina Schmiedt-Fehr1, Shwetha Kedilaya1
1University of Bremen, Institute of Psychology and Cognition Research, Bremen, Germany; Centre for Cognitive Science, Bremen, Germany.
Objective:
Patients with schizophrenia are impaired in maintaining coherent perceptual experiences. This is reflected in the oscillatory theta response and can be investigated by visual illusions. Ambiguous stimuli elicit illusory perceptual switches while the stimulus remains unchanged.
Methods:
Theta responses elicited by an ambiguous and unambiguous control stimulus were measured using the EEG during time periods of perceptual switching and perceptual stability (non-switching).
Results:
For the ambiguous task, theta activity increased during perceptual switching in healthy controls only. For the unambiguous task, the switching-related increase of theta activity was larger in controls than in patients. This reduced modulation of the theta response seems not to be related to a general decrease of theta activity in patients.
Conclusions:
These findings may be related to disturbances in the spatio-temporal integration of neural activity in patients. Reporting ambiguous and unambiguous perceptual switches seems to be more demanding for patients with schizophrenia than healthy controls.
Significance:
This is one of the first studies on the neurophysiologic correlates of illusory perception in schizophrenia. Focussing on the relation between different brain states (such as switching and non-switching) might integrate different findings about altered theta oscillations in schizophrenia.
More Related Videos
12:00Investigating the Effects of Antipsychotics and Schizotypy on the N400 Using Event-Related Potentials and Semantic Categorization
Published on: November 19, 2014
05:14Standardized Data Acquisition for Neuromelanin-Sensitive Magnetic Resonance Imaging of the Substantia Nigra
Published on: September 8, 2021
Related Concept Videos
Positive Symptoms of Schizophrenia: Hallucinations and Delusions
Thought Disorders
Disorganized and unusual thought processes mark thought disorders in schizophrenia. One key feature is disorganized speech, where an individual's conversation includes...
Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within...
Psychosis: Goals of Pharmacotherapy
Schizophrenia
Psychological and Sociocultural Causes of Schizophrenia
Positive Symptoms Schizophrenia: Hallucinations and Delusions
Hallucinations
Hallucinations in...