Unformatted text preview: nse. Thats the model of how this task
selection of a response occurs. Come back to this at the end and talk about how inhbitory comes into play with this as well. Miller & Cohen (2001)! Selection of Task-Relevant Information!
A Model of Prefrontal Control during the Stroop Task! In terms of the PFC, there is a nice demonstration of how the PFC comes in play in this fMRI study by MacDonald. Which used the Stroop
task, and looked at 2 different time points that occurred while in a typical Stroop task. The instruction/delay period (right before you have to
make a choice or decision on whether the word is colored red or colored green), and the period right after the response and whether you
make it correctly or incorrectly. Two areas of the brain are active depending on the period. So if we look at the time period right before you
have to make a response (when you have to keep the goal in mind, where the PFC has to selective a correct response or bias a certain
pathway). What you ﬁnd is that the DLPFC is much more active when it is focused on the color naming than on the word reading. The color
naming thus takes a lot more effort. The DLPFC is very sensitive to that distinction, where as the anterior cingulate is not. It doesn't make
any kind of distinction between those two choices. However, the opposite is true when you look at what happens after you make the
response. So in the case of DLPFC, when there is a conﬂict between the color and the word, it does response any differently than if there
isn't a conﬂict. But the ACC is sensitive to that. It is much more active when there is a conﬂict between how they response to the color vs
what they word is saying. So just in terms of task selection & biasing a response, it appears the DLPFC is more involved in that. When there
is a conﬂict, that is when ACC comes into play. The ACC seems to be critical in monitoring for error detection. MacDonald et al., (2000)! Mechanisms of Cognitive Control!
Selection of Task...
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- Fall '11
- Task Switching, PFC