Who is that talking? Function and dysfunction of efference copy and corollary discharge in healthy people and schizophrenic patients
type: CreativeWork
description: The concept of efference copy and corollary discharge is an attempt to explain the phenomenon that most of us recognize the outcome of self-performed actions as such and not as the result of externally generated stimuli. The planning of every motor act generates an efference copy, which is used to calculate the sensory experience this motor act will evoke and prepare the parts of the brain involved in the processing of sensory information for the upcoming stimulation. Thus, self-generated stimuli are "expected" and so the neural response to these stimuli is attenuated compared to externally generated sensory stimulation. This mechanism enables the brain to distinguish "self" from "other" A dysfunction in this internal model has been hypothesized by Frith and colleagues (e.g. Frith & Done, 1988; Frith, 1992) to underlie schizophrenic symptoms such as auditory verbal hallucinations and delusions of control. In this thesis the function and dysfunction of the efference copy mechanism during the motor act of speaking was investigated in 5 experiments A-E: Experiment A was designed to investigate how the efference copy/corollary discharge mechanism influences the neural responses to self produced speech sounds when they either match their internal predictions or when they are externally (experimentally) altered and do not match. The results show that the N100 event-related response measured using Electroencephalography was most suppressed when the subjects received auditory feedback of their own unaltered voice. It can be concluded that there is a specific forward model operating in the auditory modality, specifically suppressing neural responses only to auditory stimulation that matches closely its internal prediction. Experiment B used Magnetoencephalography to achieve a precise localization of the varying, feedback-dependent activation. Neuromagnetic Source Imaging clearly revealed auditory cortex as the place where stimuli are processed differently depending on their …
abstract: The concept of efference copy and corollary discharge is an attempt to explain the phenomenon that most of us recognize the outcome of self-performed actions as such and not as the result of externally generated stimuli. The planning of every motor act generates an efference copy, which is used to calculate the sensory experience this motor act will evoke and prepare the parts of the brain involved in the processing of sensory information for the upcoming stimulation. Thus, self-generated stimuli are "expected" and so the neural response to these stimuli is attenuated compared to externally generated sensory stimulation. This mechanism enables the brain to distinguish "self" from "other" A dysfunction in this internal model has been hypothesized by Frith and colleagues (e.g. Frith & Done, 1988; Frith, 1992) to underlie schizophrenic symptoms such as auditory verbal hallucinations and delusions of control. In this thesis the function and dysfunction of the efference copy mechanism during the motor act of speaking was investigated in 5 experiments A-E: Experiment A was designed to investigate how the efference copy/corollary discharge mechanism influences the neural responses to self produced speech sounds when they either match their internal predictions or when they are externally (experimentally) altered and do not match. The results show that the N100 event-related response measured using Electroencephalography was most suppressed when the subjects received auditory feedback of their own unaltered voice. It can be concluded that there is a specific forward model operating in the auditory modality, specifically suppressing neural responses only to auditory stimulation that matches closely its internal prediction. Experiment B used Magnetoencephalography to achieve a precise localization of the varying, feedback-dependent activation. Neuromagnetic Source Imaging clearly revealed auditory cortex as the place where stimuli are processed differently depending on their …
author: Heinks-Maldonado, Theda
keywords: Magnetencephalogramm, Ereignis-korrelierte Potentiale, corollary discharge, efference copy, auditory cortex, speech production, schizophrenia
date modified: 2026-07-24T02:22:33Z
provider: University of Freiburg
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Freiburg