Knolle, F., Schröger, E., & Kotz, S. A. (2012). Cerebellar contribution to the prediction of self-initiated sounds. Cortex, Epub ahead of print 2012.

Cerebellar contribution to the prediction of self-initiated sounds

In everyday life we frequently make the fundamental distinction between sensory input resulting from our own actions and sensory input that is externally-produced. It has been speculated that making this distinction involves the use of an internal forward-model, which enables the brain to adjust its response to self-produced sensory input. In the auditory domain, this idea has been supported by event-related potential and evoked-magnetic field studies revealing that self-initiated sounds elicit a suppressed N100/M100 brain response compared to externally-produced sounds. Moreover, a recent study reveals that patients with cerebellar lesions do not show a significant N100-suppression effect. This result supports the theory that the cerebellum is essential for generating internal forward predictions. However, all except one study compared self-initiated and externally-produced auditory stimuli in separate conditions. Such a setup prevents an unambiguous interpretation of the N100-suppression effect when distinguishing self- and externally-produced sensory stimuli: The N100 suppression can also be explained by differences in the allocation of attention in different conditions. In the current EEG-study we investigated the N100-suppression effect in an altered design comparing (i) self-initiated sounds to externally-produced sounds that occurred intermixed with these self-initiated sounds (i.e., both sound types occurred in the same condition) or (ii) self-initiated sounds to externally-produced sounds that occurred in separate conditions. Results reveal that the cerebellum generates selective predictions in response to self-initiated sounds independent of condition type: Cerebellar patients, in contrast to healthy controls, do not display a N100-suppression effect in response to self-initiated sounds when intermixed with externally-produced sounds. Furthermore, the effect is not influenced by the temporal proximity of externally-produced sounds to self-produced sounds. Controls and patients showed a P200-reduction in response to self-initiated sounds. This suggests the existence of an additional and probably more conscious mechanism for identifying self-generated sounds that does not functionally depend on the cerebellum.


Cognitive and Biological Psychology

University of Leipzig
Faculty of Life Sciences
Institute of Psychology
Neumarkt 9-19
D-04109 Leipzig


Dagmar Schrödl
Phone: +49 341 97-39570
Email: dagmar dot schroedl at uni-leipzig dot de

Dorit Thieme
Phone: +49 341 97-39540
Email: d dot thieme at uni-leipzig dot de

Fax: +49 341 97-39271