Brain activity practice exam question

[Math Is Hard]

fMRI data were collected from the brains of individuals either as they passively looked at geometric line drawings on a screen in front of them, or as they traced these drawings with their eyes. Data from the first task were subtracted from data from the second task.

What area of the brain is likely to be more active in the second task than in the first task?
(a) Primary visual cortex and frontal cortex
(b) Primary motor cortex and frontal cortex
(c) Frontal cortex alone
(d) Primary visual cortex alone

I'm stuck on this. I think it's b since there is *probably* more eye movement involved in the second task. And I think the frontal cortex might show more activity because the eye movement is being directed in a specific way in the second task.

Any thoughts? Thanks.

 

[Astronuc]

Well this is an area in which I am in the dark.

Nevertheless - I did find this -

Primates use two types of voluntary eye movements to track objects of interest: pursuits and saccades.[4] These movements appear to be initiated by a small cortical region in the brain's frontal lobe.

http://en.wikipedia.org/wiki/Eye_movement#Eye_movement_systems_.5B1.5D (The quality is questionable, but there are references).

The frontal cortex is apparently invovled, but whether alone or in concert with the motor cortex I do not know.

On the other hand -

"Their findings offer new insight into how the area in the brain’s motor cortex adjusts eye movement to track objects, say the researchers."

from Eye-movement study shows glimpse of how brain plans movement, http://www.scienceblog.com/community/older/2001/B/200112228.html

So it would appear that frontal cortex (lobe) and motor cortex are invovled together some how.

This is interesting but does not address the question.
http://www.readingonline.org/research/eyemove.html

 

[Math Is Hard]

Thanks for those links. Some of the studies referenced look very similar to ones I am reading. I feel pretty certain now that frontal cortex activity would be increased. I have been looking at some slides of eye movement tracked in passive viewing and goal directed viewing, and it is hard to tell if there is more movement overall associated in the second case, so I am still not sure about the motor cortex activity.

 

[neurocomp2003]

yes given those options your assessment is correct...i would have guessed that it was FC/PMC/PVC but there is no option for that...however perhaps they are not encoding the line itself which explains why there is no PVC

...i apologize for the abbrev, that's the way i studied
FC- has a region callled the (FEF)Frontal Eye FIelds which is suppose to be 1 of the regions for eye movement.
PMC- of course also signals for eye movement to the nerve track that leads to the eyes. Can't remmeber which way the connections go but they may even go both ways FC-PMC, PMC-FC.

the PVC: detects the low level image stuff, lines/curves/colours etc in a particular region. Basically it decomposes the image.

Other things to note:
FC - is considered Planning and perhaps learning(eg. asked to move your eye to track something).
- it also has regions called FEF(given above), PreFC, dorsolateralFC,
OrbitoFC,SMA(supplementary motor associations..i hope i got this one right). I thought the PMC was part of the frontal cortex.

Spatial Manipulations and Spatial Imagery(imaging stuff) occurs in the Parietal-Occiptal region just above the PVC.

 

[Math Is Hard]

hey neurocomp, thanks for your reply. I appreciate your feedback.
I had to run off an study for an exam. I had to do some brain labeling on the test, Don' t know how well I did, but I gave it my best shot.

 

[Moonbear]

Sorry I didn't see this thread earlier, so it's probably too late now.

yes given those options your assessment is correct...i would have guessed that it was FC/PMC/PVC but there is no option for that...however perhaps they are not encoding the line itself which explains why there is no PVC

The key is that the question isn't asking which areas are activated by each task, but which ones might be activated differently by the two tasks. So, the PVC would be expected to be activated in both cases, but since it's the same line either way, it shouldn't differ between the two examples given. The differences would be in the areas involved specifically in the visual tracking task.

So, other than that little detail, it looks like the answers were all on track.