Neurophysiological evidence for a processing bias towards schizophrenia-associated communication abnormalities

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Clinical Psychology

Background:

• Investigating how diagnostic and symptomatic information influences auditory linguistic event-related potentials (ERPs).
• Examining listener responses to speech with schizophrenia-associated communication abnormalities.

Purpose of the Study:

• To determine the impact of diagnostic labels on auditory ERPs.
• To understand how listeners process speech abnormalities in the context of schizophrenia.

Main Methods:

• 73 participants underwent continuous EEG recording while listening to conversation segments.
• Participants were informed the speaker had varying conditions: university student, stroke symptoms, schizophrenia symptoms, or recovered from schizophrenia.
• Speech endings were manipulated (typical, approximation, neologism, filler).

Main Results:

• A significant N400 ERP component was observed over centro-parietal sites for word approximations and neologisms exclusively in the university student condition.
• No significant differences in the N100 ERP across conditions.
• EEG measures did not correlate with subjective or objective stigmatizing attitudes.

Conclusions:

• The N400 effect may indicate semantic-level disengagement from speech content when diagnostic or symptomatic information about schizophrenia is present.
• Listener's brain activity reflects processing differences based on perceived speaker diagnosis.