An fMRI approach to particularize the frontoparietal network for visuomotor action monitoring: Detection of incongruence between test subjects’ actions and resulting perceptions Knut Schnell, a, ⁎ Karsten Heekeren, a Ralf Schnitker, b Jörg Daumann, a Jochen Weber, b Volker Heßelmann, c Walter Möller-Hartmann, c Armin Thron, d and Euphrosyne Gouzoulis-Mayfrank a a Department of Psychiatry and Psychotherapy, University Hospital of Cologne, Kerpener Str. 62, 50924 Cologne, Germany b Interdisciplinary Center for Clinical Research, University Hospital of the Technical University Aachen, Aachen, Germany c Department of Radiology, University of Cologne, Cologne, Germany d Department of Neuroradiology, University Hospital of the Technical University Aachen, Aachen, Germany Received 24 February 2006; revised 16 August 2006; accepted 21 August 2006 Contemporary theories of motor control assume that motor actions underlie a supervisory control system which utilizes reafferent sensory feedbacks of actions for comparison with the original motor programs. The functional network of visuomotor action monitoring is considered to include inferior parietal, lateral and medial prefrontal cortices. To study both sustained monitoring for visuomotor incongruence and the actual detection of incongruence, we used a hybrid fMRI epoch-/event- related design. The basic experimental task was a continuous motor task, comprising a simple racing game. Within certain blocks of this task, incongruence was artificially generated by intermittent takeover of control over the car by the computer. Fifteen male subjects were instructed to monitor for incongruence between their own and the observed actions in order to abstain from their own action whenever the computer took over control. As a result of both sustained monitoring and actual detection of visuomotor incongruence, the rostral inferior parietal lobule displayed a BOLD signal increase. In contrast, the prefrontal cortex (PFC) exhibited two different activation patterns. Dorsolateral (BA 9/46) and medial/cingulate (BA 8, BA 32) areas of the PFC displayed a greater increase of activation in sustained monitoring, while ventrolateral PFC showed greater event-related activation for the actual detection of visuomotor incongruence. Our results suggest that the rostral inferior parietal lobule is specifically involved in the reafferent comparison of the test subjects’ own actions and visually perceived actions. Different activation patterns of the PFC may reflect different frontoparietal networks for sustained action monitoring and actual detection of reafferent incongruence. © 2006 Elsevier Inc. All rights reserved. Keywords: fMRI; Action monitoring; Motor control; Inferior parietal lobe; Visuomotor control Introduction Contemporary theories of motor control assume that motor actions underlie a supervisory control system which utilizes reafferent sensory feedbacks of actual movement consequences for comparison with the original motor programs (Wolpert, 1997; Prinz, 1997). This reafferent control system is considered to be involved in various functions like motor guidance, sensory gating and the generation of awareness about an individual’ s own actions. In addition, the reafferent monitoring system is capable of automatic adjustment to changes of the target location or feedback distortions during movement execution. Within certain spatial and temporal limits, the reafferent adjustment is automatically per- formed without subjective awareness of the corrections (Fourneret and Jeannerod, 1998). In fact, awareness of the actual state of the motor system rarely emerges as long as the originally intended objectives of actions are achieved. For sensory gating, a “feed-forward” system of action monitor- ing is hypothesized to generate predictive models about perceptual consequences of motor plans (Wolpert, 1997; Frith et al., 2000). Insufficient predictive sensory gating and reduced awareness of differences between self-intended and external actions in schizo- phrenic patients (Blakemore et al., 2000; Franck et al., 2001) suggest that disturbed representation of own motor plans might be fundamental regarding certain psychotic symptoms such as hallucinations and particularly delusions of control (Spence et al., 1997; Frith et al., 2000). In addition, motor control implies a continuous demand to differentiate between consciously executed movement programs and externally triggered automated movement patterns. The external triggering of automated movements – for example, grabbing a cup or a piece of fruit located in a hand’ s spatial field of action – is normally suppressed. This suppression can, however, be invalidated by circumscribed cerebral lesions, such as an infarction of the right www.elsevier.com/locate/ynimg NeuroImage 34 (2007) 332 – 341 ⁎ Corresponding author. Fax: +49 221 4786605. E-mail address: knut.schnell@uk-koeln.de (K. Schnell). Available online on ScienceDirect (www.sciencedirect.com). 1053-8119/$ - see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.neuroimage.2006.08.027