Open mdnunez opened 8 years ago
From @bob-carpenter on April 20, 2016 17:0
Any helpful pointers to what needs to be changed in other parts of Stan code would be appreciated.
See:
The current version of the Ratcliff likelihood is located here. Tests still need to be implemented by coping and editing wiener_test.hpp
@mdnunez, thanks for your efforts! This is exactly what I need for my current work.
From @mdnunez on April 19, 2016 23:50
New Feature Suggestion:
Add a Wiener likelihood function with intrinsic trial to trial variability in the drift rate, titled the "Ratcliff" likelihood function
Description:
Adding a parameter that describes the variance in drift rate over trials to the Wiener likelihood function yields better estimates of incorrect reaction time (see Table 3 of Nunez et al, 2016 for an example deficit of incorrect-RT prediction with a hierarchical version of the simple Wiener likelihood). This version of the diffusion model and its extensions was popularized by Ratcliff (1978; see also Ratcliff and McKoon, 2008) and is used widely in the mathematical psychology and neuroscience communities. Because of sampling techniques developed by Navarro and Fuss (2009) and probability density function derivations by Tuerlinckx (2004), it is relatively straight-forward to copy and change the existing Wiener likelihood sampler in Stan to include intrinsic trial-to-trial variability. This method has already been implemented by existing hierarchical "drift-diffusion" model samplers (Wiecki, 2003).
Additional Information:
I have a version of "ratcliff_log.hpp" code mostly finished however it needs to be tested and compared to simulations. Any helpful pointers to what needs to be changed in other parts of Stan code would be appreciated.
Citations:
Current Version:
v2.9.0
Copied from original issue: stan-dev/stan#1875