Dresden 2009 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 26: Poster II
DY 26.16: Poster
Donnerstag, 26. März 2009, 16:00–18:00, P1A
Cognitive Aging as a Loss of Criticality — •Hecke Schrobsdorff1,2, Matthias Ihrke1,2, Jörg Behrendt1,3, Marcus Hasselhorn1,3,4, and J. Michael Herrmann1,2,5 — 1BCCN Göttingen — 2MPI for Dynamics and Self-Organization Göttingen — 3Georg-Elias-Müller Institute for Psychology Göttingen — 4German Institute for International Educational Research Frankfurt — 5School of Informatics at the University of Edinburgh
The performance in psychological tests of fluid intelligence such as Raven's Advanced Progressive Matrices, tends to decrease with age [1]. These results are in obvious contrast to performance improvements in everyday situations [2]. We hypothesize that the observed aging deficits are partly caused by learning.
We consider a network of integrate-and-fire neurons with dynamical synapses, where critical behavior is a generic phenomenon [3] which might provide a suitable basis for tasks like Raven's test where the exploration of a large set of combinations of features is required. The synaptic adaptation by learning reoccurring neural-activity patterns is shown to cause a breakdown of the critical state. Networks with comparatively lower memory load achieve more stable activations of new feature combinations than 'old' networks. This corresponds well to the results of the free-association mode in either network type where only the 'young' networks are close to a self-organized critical state.
[1] R L Babcock. Intelligence (2002) [2] T A Salthouse. In: Handbook of the psychology of aging (1999) [3] A Levina, J M Herrmann and T Geisel. Nature Physics (2007)