Jumping to Associations during Psychosis

Abstract

Objectives: Psychoses are aetiologically complex disorders that affect about 1 − 2% of the population during their lifetime. Psychotic symptoms are thought to represent disturbances in higher-order brain functions that can be grouped according to their dysfunction in one or more of the following three neural brain circuitries: language, affect, motor function. Dysfunction of the neural language brain circuitry has already been linked to disturbances in expressive speech and formal thought disorders. However, it remains currently unknown if all psychosis patients show to some extent a disruption in the language brain circuitry or if this is only the case for patients with language and thought disturbances. Furthermore, it is still unclear if the language brain circuitry is only disturbed in psychosis, or if already individuals at familial or clinical high-risk show some extend of aberrancy. Methods: To examine the whole spectrum form health to psychosis, four different subject groups are being examined: healthy controls, first-degree relatives of psychosis patients, a clinical high-risk group and psychosis patients. In total, 120 subjects (30 per group) will complete a lexical priming task during electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). The lexical priming task consists of two subtasks. During the category subtask, subjects have to decide whether a visually presented target word forms the generic term of the previously shown prime word in terms of its category (e.g. Apple – Fruit). During the association subtask, participants have to indicate whether a visually presented target word is related to the content of a previously shown prime word (e.g. Apple – Pear). Expected Results: Preliminary data from the fMRI part will be shown from this proof of concept study. In this sample, both conditions revealed a bilateral activation pattern in the IFG (Broca’s region). Thus, the language task activates the neural language circuitry