Reference no: EM132461464
1. In class we discussed the drift-diffusion model (DDM) with attention. In this model the "drift rate" or rate of evidence accumulation depends on the stimulus values (or "ratings") of the two choice options, as well as which option is currently being looked at. So when the decision maker is looking at the left item the drift rate is uleft - θuright and when the decision maker is looking at the right item, the drift rate is θuleft - uright.
(a) Suppose that the attention parameter θ = 0.9. For the following choice problems, compute the drift rate when the decision maker is looking left and looking right.
(i) uleft = 4, uright = 7
(ii) uleft = 2, uright = 1
(iii) uleft = 9, uright = 10
(b) Suppose that the attention parameter is instead θ = 0.2. For the same choice problems, compute the drift rate when the decision maker is looking left and looking right.
(i) uleft = 4, uright = 7
(ii) uleft = 2, uright = 1
(iii) uleft = 9, uright = 10
(c) For which of the two θ values above is there a bigger difference in the drift rate depending on where the decision maker is looking?
(d) Is the effect of attention stronger or weaker for high stimulus values compared to low stimulus values? (hint: compare (ii) and (iii)).
(e) Name the two brain regions that seem to track this change in drift rate depending on where the decision maker is looking.