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Questions about the Fractal Scaling Relative to the Experimental Subjects' Brain Dominance, IQ, and Educational Attainment #1

Open jmausolf opened 5 years ago

jmausolf commented 5 years ago

Excellent paper and thanks for contributing! Not having much experience with this field, I was curious to learn more about the some of the methods regarding the selection of experiment subjects and how they might affect fractal scaling, and brain dynamics more generally, versus task complexity. One of the first questions, I regards left-versus right-hand dominance. Both the SART and TMT dataset and VWMT dataset note that all subjects were right-handed. Were subjects in the MTAS dataset also right handed? If not, what effect would this likely have on the results?

Second, I am curious how the cognitive baselines of experimental subjects, such as their educational attainment or IQ, might affect the results. For example, if fractal dynamics vary as a function of cognitive effort as it relates to task complexity or task novelty, would we expect to see a constant relationship to fractal scaling if the experiments were run on different subgroups with discrete levels of baseline cognitive function (say a group of healthy but low-IQ and low-educational attainment subjects versus a group of healthy, high-IQ and high-educational attainment subjects)? For the different datasets used in the study, how representative were the subjects' IQ and educational attainment of the general population?

bermanm commented 5 years ago

Hi Josh,

         Most fMRI experiments restrict to right handers because left handers have differential brain activity especially for tasks that involve language (right handers are more left lateralized and left handers are more bilateral).  We did not collect these datasets for the purpose of examining the Hurst Exponent and effort so we were a bit stuck with the original designs.  That being said, I'm not too worried that handedness would have any effect.  For your second question, I think if different groups of participants would find that tasks easier or harder that would certainly affect fractal scaling.  The participants are fairly representative and I would say, and not just a college aged sample.  This is something that many MRI experiments need to improve upon though.

Looking forward to chatting more.