Accurate and precise parameter recovery with the basic TWIN model

Farid I Kandil, Hans Colonius, Adele Diederich

Last modified: 2013-06-02

Abstract


The "time window of integration" (TWIN) model (e.g. 1,2) allows to predict response speed effects in multisensory settings. E.g., in the focused attention paradigm (FAP), subjects are instructed to respond to stimuli of the target modality only, yet reaction times are shorter if the unattended stimulus is presented in a certain temporal relation to the target stimulus. The TWIN model accounts for these cross-modal effects by proposing that all the initially unimodal bits of information must arrive at the point of integration within a certain time window in order to be integrated and thus to allow response enhancements like the observed reaction time reductions. It has been successfully used to account for empirical data. Here, we conduct a parameter recovery study of the basic TWIN model with five parameters for the duration of the visual and acoustic unimodal and the integrated second stage, the length of the time window, and the size of the effect. We conducted 576 “experiments“ with different parameter value sets, each comprising 500 “subjects“, for which data for 80 trials in a FAP setting were generated, averaged and fed into the recovery process. Parameter estimations were evaluated in terms of absolute and relative accuracy and precision. Results show that deviations from the true value are of only insignificant size for all parameters. Especially duration parameters for the unimodal stage of the focused stimulus and the integrated second stage are both highly accurate and precise, in fact to such an extent that they match statistics of single cell recordings.

Keywords


model; reaction times; focuse attention paradigm (FAP); time window; parameter recovery study

References


1. Colonius, H. & Diederich, A. (2004) Multisensory interaction in saccadic reaction time: A time-window-of-integration model. J Cogn Neurosci, 16, 1000-1009. 2. Diederich, A. & Colonius, A. (2008) Crossmodal interaction in saccadic reaction time: Separating multisensory from warning effects in the time window of integration model. Exp Brain Res, 186, 1-22.

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