Physiological Explanation of Function Development

The human mind is made up of defined regions in the brain. While science hasn't defined all the regions of the brain, we have mapped out quite a few and have a rather solid grasp on what these regions do.

In particular, we've mapped out the limbic system. Here is a brain scan of a highly limbic mind, outlining the limbic system and its components very well.

View attachment 3161

And here are some illustrations of these areas to help understand the proximity of these regions to one another.

View attachment 3162

View attachment 3163

And here is a rotating 3D model showing the Limbic System in red.



From what we can tell, the cognitive functions strongly reside in various regions of the brain, as people who have dominant functions show elevated activity in these respective regions. In particular, Ni is showing itself to be strongly centered in the Cingulate System, but not the rest of the Limbic System. While Fi and Ne are showing themselves to be centered in the overall Limbic System, with Ne leaning toward the Cingulate side of the Limbic System and Fi leaning toward the more instinctive side of the Limbic System. Fe appears to be a mix of the more instinctive side of the Limbic System and Frontal Lobes. Interestingly enough, Te appears to be dominantly centered in the Frontal Lobes.

The next thing to understand about the brain is that it is a gigantic neurochemical mass. Note, the use of the term chemical. It is a well established fact that areas of neural activity will stimulate nearby clusters of nerves. High amounts of activity in one area of the brain will stimulate other nearby regions of the brain because the chemical and electrical activity will physically seep into other parts of the brain.



All of this scientific and medical jargon is going somewhere, I promise.

What this means for any personality type is that the cognitive processes that the individual uses on a regular basis will greatly stimulate those areas of the brain, and the regions near those areas are likely to be stimulated as well, likely resulting in eventual development.

For the INFJ mind, this means that the individual inherently has a highly active Cingulate System, as well as a moderately active lower Limbic System and Frontal Lobe. As the individual develops more and more capacity with Ni, the Cingulate System begins to stimulate the remaining Limbic System, as well as some of the depper Frontal, Parietal, and Temporal Lobe regions (reinforcing Fe, but also stimulating Ti and Se) that are nearby. Meanwhile, as the INFJ develops Fe, they will also stimulate other areas of the Limbic System (reaching into Fi and Ne territory) and the Frontal Lobe (reaching into Te territory). This is why so many INFJs develop Ni, Fe, Fi, and Ne preferences, and are prone to also develop rather solid Te. This is also why INFJs seldom develop much in the way of Se and Si, because the regions of the brain which are most active for these functions are further from the primary centers of activity for an INFJ.

Interestingly enough, there is a fair amount of overlap with the other NF types and cognitive processes due to the nature of where the processes reside physiologically. Ni, Ne, Fi, and to a lesser extent Fe all seem to have the most activity concentrated in the Limbic and Cingulate Systems. This is why there are so many similarities in preferences in the more developed INFJs, ENFJs, INFPs, and ENFPs.

It also stands to reason that this pattern of development and similarity would apply to the other type groups, such as Keirsey's SJ, SP, and NT models. As I do more research on the remaining cognitive processes and their dominant regions, I will not be surprised if I uncover similar connections.

Anyway, this is a physiological explanation for all of this stuff we've been discussing.

 

Thanks. I've been tinkering on this theory for a while now.

In effect yes. All of the N types, whether Ni or Ne users, have a stronger tie to their Cingulate system than their sensory systems.

Yes, but keep in mind that Te and Fi are in different parts of the Frontal Lobe and Limbic System than Fe.

INTJs have a larger path between the Cingulate (Ni), into the upper Frontal Lobe (Te), and then back to the lower end of the Limbic system (Fi), before cycling through the back end of the sensory centers (Parietal and Occipital Lobes) which pulls back to the Cingulate system 'switchboard' - it's a more efficient process loop because it uses less energy and glucose, but less inclusive of a lot of things. It's also a very 'vertical' circuit in that it doesn't reach deeply into either hemisphere for detail recognition or micro analysis, but instead stays more in the center of the brain. This gives them that detached 'robotic' effect, as well as leaves them less able to focus on physical details than INFJs.

View attachment 3166

INFJs run a different path from Cingulate (Ni) down into a dual process of upper Limbic and lower Frontal Lobe (Fe), then splitting into two dual tracks sideways into the Temporal Lobes (Ti) before converging back in the sensory centers (Parietal and Occipital Lobes) and cycling back to the Cingulate System 'switchboard'. The INFJ loop is less efficient with respect to energy and glucose, but it is a dual process reasoning, so we have the advantage of better detailed thought and observation than the INTJs as we also use more of both hemispheres in this process. The down side is that we also tend to think in a constant state of polarities which leads us to be less decisive, and less able to see the big picture.

View attachment 3164

So while both types have Ni and Se, they actually use those regions of their minds slightly differently. INTJ Cingulate activity is slightly more focused on the top middle of the Cingulate Gyrus which better connects with the upper Frontal Lobes (Te), while INFJ Cingulate activity is more focused in the front and back of the Cingualte Gyrus which simultaneously reach into the Limbic and lower Frontal Lobes (Fe). This Ni activity is similar, as in both are active in the majority of the Cingulate Gyrus, but notably different. However, both types use Se very differently. INTJs roll through the inner Se associated regions of the brain (Parietal and Occipital Lobes) in a linear fashion - moving upward from the Limbic system - avoiding the outer parts of the hemispheres before sending the circuit back to the Cingulate Gyrus. INFJs move through the outer parts of the Parietal and Occipital Lobes simultaneously left and right before converging in the center of the brain and cycling back to the Cingulate Gyrus. In other words, INTJs and INFJs use Se very differently because INTJs maintain a solid thought process through their lesser functions (Te, Fi, and Se) while INFJs split into a dual process through their lesser functions (Fe, Ti, and Se).

View attachment 3167View attachment 3165

The Parietal and Occipital Lobes are where Se and Si seem to be the most focused. However, just as with the Limbic and Frontal Lobes, they seem to share space in upper and lower regions. Si reaches into the Temporal Lobes which is shared with Ti, and Se appears to reach (not surprisingly) into the Limbic System with Fi. In these individuals the Cingulate system acts as a switchboard, not the controller, allowing the opposite ends of the brain to communicate. This is why Ni and Ne are consulted last in their thought processes.

There is a lot of overlap in all of the regions, making this a very fascinating area of exploration, but also seems to make more sense than not.

(It also proves a lot of what we thought we knew about right and left brained theory to be wrong, especially with respect to the cognitive processes. It looks as if those wacky theories of Lenore's are about to be proven wrong.)

 

Also for Shai Gar, here is the ENTP cognitive progression....

View attachment 3190

 

Thank you!

Very much so.