Litvak, V;
Jafarian, A;
Zeidman, P;
Tibon, R;
Henson, RN;
Friston, K;
(2019)
There’s no such thing as a ‘true’ model: the challenge of assessing face validity*.
In:
Proceedings of the 2019 IEEE International Conference on Systems, Man and Cybernetics (SMC).
(pp. pp. 4403-4408).
IEEE: Bari, Italy.
Preview |
Text
IEEE_face_validity.pdf - Accepted Version Download (597kB) | Preview |
Abstract
To select among competing generative models of timeseries data, it is necessary to balance the goodness of fit (accuracy) and model complexity. Bayesian methods are a mathematically principled way to achieve this balance. However, when performing simulations – to assess the identifiability of models (face validation) – the best model identified by Bayesian model comparison might appear more complex than the model that actually generated the data. We illustrate this using dynamic causal models of human electrophysiological data, where models with multiple parameter modulations are selected as the best model, even if the true modulations are sparse. We explain this by the form of the complexity penalty, which is equivalent to weighted L2 norm. This phenomenon is an example of implicit prior biases that necessarily entail a complexity penalty.
| Type: | Proceedings paper |
|---|---|
| Title: | There’s no such thing as a ‘true’ model: the challenge of assessing face validity* |
| Event: | 2019 IEEE International Conference on Systems, Man and Cybernetics (SMC) |
| Dates: | 06 October 2019 - 09 October 2019 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1109/smc.2019.8914255 |
| Publisher version: | https://doi.org/10.1109/smc.2019.8914255 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Brain modeling , Data models , Computational modeling , Mathematical model , Face , Modulation , Analytical models |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Imaging Neuroscience |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10087449 |
Archive Staff Only
 |
View Item |
