[ACT-R-users] Vision: estimate distances and pattern extrapolation?

[David Reitter]

All,

I wonder if you have some ideas on models that could describe pattern recognition or implicit distance estimation.

I am looking at an experiment that requires subjects to estimate the difference between two or more visible dots and extrapolate along line between them to foveate on a spot.  
Alternatively, one could think of it as pre-attentive processing, recognizing the dots and extrapolating the pattern in one direction (and foveate on that spot):



	. 		.		.		X


(Dots . are shown, and X is where I want to foveate, without anything being shown there.)


It seems that the standard vision module does not give me the angle or distance between two screen locations (or finsts), although I could of course calculate that if I had the coordinates.  The precision of the estimates is unclear, though.  Referring to the ACT-R 6 manual, I don't see how I would get coordinates or estimate distance.

As for the saccadic movement, EMMA would be a good reference point: "Given a saccade to a particular object, the model assumes that the landing point follows a Gaussian distribution around the center of the object. (...)"  (Salvucci, 2001)  - Is this assumption still state of the art?

(I don't care much for timing in my model.)

There are models of many visual tasks out there (reading, object recognition/WHAT system, eye-movement), but what models explain aspects of pattern recognition or at least distance estimation?

Thanks for your input.


====

Some related literature:

Halverson, An “Active Vision” Computational Model Of Visual Search
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA518836

Oleksiak et al, Distance Estimation Is Influenced by Encoding Conditions
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2847905/

Salvucci, An integrated model of eye movements and visual encoding [EMMA]
http://www.sciencedirect.com/science/article/pii/S1389041700000152
[and various preceding work listed there, 



-- 
Dr. David Reitter
Assistant Professor of Information Sciences and Technology
Penn State University
http://www.david-reitter.com