OS_29. Perception and action
Saturday, October 01st, 2011 [16:20 - 17:20]
OS_29.1 - How sensory anticipations in the human brain control motor action
Pfister, R. 1 , Melcher, T. 2 , Kiesel, A. 1 , Dechent, P. 3 & Gruber, O. 2
1 Department of Psychology III, University of Würzburg. Würzburg, Germany.
2 Department of Psychiatry and Psychotherapy, Georg-August-University Göttingen. Göttingen, Germany.
3 MR-Research in Neurology and Psychiatry, Georg-August-University Göttingen. Göttingen, Germany.
How does our mind produce physical action of our body? How are goals transformed into overt behaviour? For about 200 years, philosophers and psychologists hypothesized the transformation from mind to body to occur via the anticipation of sensory consequences of an action. And whereas there is ample evidence for this hypothesis in behavioural experiments, the neural underpinnings of action control via sensory anticipations are virtually unknown. Consequently, current neuroscientific models of action control do not account for this mechanism. Using a response-effect compatibility paradigm and functional magnetic resonance imaging, the present study identified the inferior parietal cortex and the parahippocampal gyrus as key regions for this type of action control. These findings set the stage for a neuroscientific framework for explaining action control by sensory anticipations and thus a potential synthesis of psychological and neuroscientific approaches to human action.
OS_29.2 - Cognitive control and mental rotation speed predict surgical skills
Band, G. P. 1, 2 , Piederiet, A. 1 , Hultzer, G. 3 & Hamming, J. 3
1 Leiden University Institute of Psychology
2 Leiden Institute for Brain and Cognition
3 Leiden University Medical Center
Vascular surgery and laparoscopy require complex cognitive and motor skills, such as spatial transformations and flexibility of rule application. We tested the predictive value of cognitive psychological indices for these surgical skills, making use of a skills lab approximation of actual surgery: participants had to perform complex motor operations with indirectly controlled tools, visible through a monitor from an unnatural perspective. Performance in this skills lab has previously been shown to be a valid indicator of performance in actual surgery on human patients. After performing on the Simon, the mental rotation and the task switching paradigm, 32 medicine students without prior surgery experience engaged in three skills lab tests, alternated with skills lab practice. From the tests, both baseline and improvement scores were derived in subtests such as stringing beads, folding a pipe cleaner, and cutting a circle from a balloon. All cognitive psychological indices explained at least some of the lab skills significantly. The strongest predictor was local switch costs; the speed difference of switch trials versus repetition trials in a block with mixed instructions. These results are a first step towards improving the quality of both surgery training and surgery practice.
OS_29.3 - Top-down modulation of action perception
Cross, E. 1, 2, 3 , Liepelt, R. 1, 4 , Prinz, W. 1 & Hamilton, A. F. d. C. 5
1 Department of Psychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
2 Behavioural Science Institute & Donders Institute for Brain, Cognition & Behaviour, Radboud University Nijmegen, The Netherlands
3 Department of Psychology, Bangor University, Wales, UK
4 Institut für Pscyhologie, Westfälische Wilhelms Universität Münster, Germany
5 School of Psychology, University of Nottingham, Nottingham, UK
In the human brain, top-down modulation has a substantial impact on whether information is processed as ‘social’ or ‘non-social’. Theory of mind studies have used the same stimuli for ‘human’ and ‘computer’ conditions, and found that the identical stimulus activates social brain regions when participants believed the observed action originated in another person, not a computer. Here we tested for modulation of actions perceived as social/non-social, based on instructions and the actor’s form. Before scanning, participants watched a video instructing how avatars could be animated entirely by computer or by capturing motions of a real human actor. During scanning, participants saw computer-generated ‘Poser’ figures (one human-like and the other robot-like in appearance) performing simple goal-directed actions. Both figures performed the same actions with identical kinematics, but participants were told that half the videos were created with motion capture, and the other half with computer animation. Imaging data reveal stronger occipital activations when perceiving the robotic versus the human form, and a broad network of regions including inferior occipital, fusiform, and posterior cingulate cortices when participants believed they were watching human-generated actions. The present data thus demonstrate how top-down (instructions) and bottom-up (agent form) features work together to modulate action perception.