Regensburg 2007 – scientific programme
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BP: Fachverband Biologische Physik
BP 12: Neuroscience
BP 12.4: Talk
Tuesday, March 27, 2007, 11:30–11:45, H44
Modeling Neural Correlates of Selective Attention — •Hecke Schrobsdorff1,2, Matthias Ihrke1,3, Jörg Behrendt1,3, Björn Kabisch1, Marcus Hasselhorn1,3, and Michael Herrmann1,2 — 1Bernstein Center for Computational Neuroscience Göttingen — 2Institute for Nonlinear Dynamics — 3Georg-Elias-Müller Institute, Göttingen University
In order to reveal cognitive mechanisms of selective attention, we study the paradigm of negative priming. In negative priming experiments, subjects have to discriminate a target from a distractor stimulus. While identical targets in two subsequent displays, the positive priming condition, leads to a speedup in reaction time, the opposite effect, a slowdown, is achieved if the former distractor becomes target in the actual display, called negative priming.
We model the process of discrimination by a dynamical systems approach with an adaptive threshold suppressing irrelevant stimuli. Our model perfectly explains phenomenological data, furthermore it makes predictions about behavior in rare stimulus configurations. Semantic representations of different stimuli are modeled by an activation level of cell assemblies. Therefore the model provides an interpretation of systematic variations of event related potentials from EEG recordings during negative priming trials.