title: Dynamical systems analysis applied to working memory data.
abstract: In the present paper we investigate weekly fluctuations in the working memory capacity (WMC) assessed over a period of 2 years. We use dynamical system analysis, specifically a second order linear differential equation, to model weekly variability in WMC in a sample of 112 9th graders. In our longitudinal data we use a B-spline imputation method to deal with missing data. The results show a significant negative frequency parameter in the data, indicating a cyclical pattern in weekly memory updating performance across time. We use a multilevel modeling approach to capture individual differences in model parameters and find that a higher initial performance level and a slower improvement at the MU task is associated with a slower frequency of oscillation. Additionally, we conduct a simulation study examining the analysis procedure's performance using different numbers of B-spline knots and values of time delay embedding dimensions. Results show that the number of knots in the B-spline imputation influence accuracy more than the number of embedding dimensions.
authors: Department of Psychology, Ulm University Ulm, Germany.
authors: Fidan
authors: F
authors: Gasimova
authors: Federal Institute for Education Research, Innovation and Development of the Austrian Schooling System (BIFIE Salzburg) Salzburg, Austria.
authors: Alexander
authors: A
authors: Robitzsch
authors: Department of Psychology, Ulm University Ulm, Germany.
authors: Oliver
authors: O
authors: Wilhelm
authors: Department of Psychology, University of Virginia Charlottesville, VA, USA.
authors: Steven M
authors: SM
authors: Boker
authors: Department of Psychology, Texas State University San Marcos, TX, USA.
authors: Yueqin
authors: Y
authors: Hu
authors: Department of Psychology, Humboldt University Berlin, Germany.
authors: Gizem
authors: G
authors: Hülür
keywords: B-spline imputation; dynamical systems analysis; intensive longitudinal data; intraindividual variability; simulation study