Symposium

Decision Making in Goal-Directed Behavior

April 20/21 (2009), De Poort, Groesbeek, the Netherlands



The ability to select an appropriate response in a rich, dynamic and unpredictable environment is of utmost importance for the survival of an organism. Similar stimulus conditions may require completely different responses, depending on context. When a ball is thrown at us we can estimate its trajectory, orient towards it, initiate a catching movement and form the appropriate grip all in a split second. When on the other hand a rock falls from a mountain and threatens to hit us we are able to quickly plan quite a different response: an exact escape path in time and space that we can even change when the rock suddenly changes its course.

Experiments under simplified laboratory conditions have revealed that the brain can program and update adequate orienting responses on a millisecond timescale, even under dynamic perturbations of the motor system, while it can react to sudden changes of stimulus properties. This remarkable capacity indicates that our behavioral repertoire is controlled by dynamic feedback that is modulated by context and shaped by past experience, which is thought to be represented by an 'internal model' of our sensorimotor system. An important aspect in this process, so far overlooked in typical laboratory conditions, is the stochastic nature of the natural environment, and the fact that the brain has to cope with its own inherent noise and significant processing delays. Furthermore, several disorders of neuronal response selection systems lead to specific response selection deficits, indicating a specialized neuronal circuitry underlying different forms of response selection. Recent evidence suggests that already at an early perceptual stage a planned act prioritizes certain percepts of the outer world over others. A comprehensive understanding of how the primate central nervous system is able to perform optimally under such dynamic and uncertain conditions in complex environments is still lacking.

This symposium envisions a multidisciplinary approach for elucidating the neuronal mechanisms behind response selection in rich and dynamic environments. The topics will range from perceptual selection to action planning and competition between response alternatives.

The methods of interest will include:

Because the multidimensionality of the problem is too complex for any single laboratory to tackle, a unified multidisciplinary collaboration is deemed essential. The data extracted from the different approaches can be used to develop theoretical models that integrate findings from single-neuron recordings, activation patterns observed across large areas of the brain (EEG, fMRI), results of dysfunction of response selection systems in patient groups, and the ensuing behavioral responses.

International experts on the topic will give presentations, followed by plenary discussions. PhD and MSc students working on relevant topics are welcomed to present their work in poster sessions.

The organizing committee: