Jun 14, 2011

Feedback Loop of The Brain

One of the more interesting concepts of control systems is the feedback loop. Systems that have a feedback loop are called a closed-loop systems which use feedback to control states or outputs of a dynamical system. These systems are "aware" of their output through the feedback loop and can adjust the input if the desired output is not being achieved. These systems are, hence, superior to open loop systems where there is no feedback and hence adjustment of the input to calibrate the output to a desire result. 
Applying the feedback loop concept to people, those who are mindful of their actions and constantly evolve their personalities and behaviors based on feedback they receive from their surroundings can be said to have a feedback loop. This allows the person to adapt, innovate and evolve within a community or group based on input and learning from his or her environment or social network. However, there are also those whose personalities seem to be set in stone and never change regardless of circumstances. This second type of people symbolize the open-loop system with no feedback. The question, however, is that, how is it that some people have very good feedback loops while others don't.  Perhaps the following excerpt from a Times article (Optimism Bias) can address this question:

"Examining the brain-imaging data, researchers found that the students' brains responded differently to the mistakes they made depending on whether they were primed with the word clever or the word stupid. When the mistake followed positive words, she observed enhanced activity in the anterior medial part of the prefrontal cortex (a region that is involved in self-reflection and recollection). However, when the participants were primed with the word stupid, there was no heightened activity after a wrong answer. It appears that after being primed with the word stupid, the brain expected to do poorly and did not show signs of surprise or conflict when it made an error.  A brain that doesn't expect good results lacks a signal telling it, "Take notice — wrong answer!" These brains will fail to learn from their mistakes and are less likely to improve over time. Expectations become self-fulfilling by altering our performance and actions, which ultimately affects what happens in the future. Often, however, expectations simply transform the way we perceive the world without altering reality itself."
From this study it seems like that it all comes down to confidence. If someone is confident in their intellectual and learning abilities then they are always aware of their shortcomings and understand that they can always learn, change and evolve to adapt to their dynamic environment. However, a low confidence in learning and intelligence abilities leads to a passive approach where one feels like they do not have the ability to understand the situation as well as the ability to know how to change oneself to adapt. This second state of mind is one with no feedback loop or evolution. Once an opinion or understanding of a situation is constructed, it rarely gets updated or modified, regardless of additional information or input. This approach, usually adopts ideologies, opinions and judgement from others (Media, Social Network) and rarely forms independent positions based on analysis of different data and view points. That being said, even people with good feedback loops have to turn off the feedback at some point in order to be able to make a decision or form an opinion. Otherwise, they will be paralyzed in analysis and infinite feedback data. In today's information age, input never stops, so in order to make a judgement we have to at times ignore or filter the feedback loop to form a decision or an opinion.  Just like having a feedback loop is necessary to adapt to changes in life, having a filter is equally important to evaluate all feedback data or we will cease to have a self or a personality and constantly change based on feedback.  Here is another view of the feedback loop concept in terms of human behavior by psychologist Iain McGilchrist author of The Master and His Emissary:

I think we can also make a connection here with a rather fundamental difference between the hemispheres of the brain. The left hemisphere's ‘stickiness’, its tendency to recur to what it is familiar with, tends to reinforce whatever it is already doing. There is a reflexivity to the process, as if trapped in a hall of mirrors: it only discovers more of what it already knows, and it only does more of what it already is doing. The right hemisphere by contrast, seeing more of the picture, and taking a broader perspective that characteristically includes both its own and the left hemisphere's, is more reciprocally inclined, and more likely to espouse another point of view. One way of thinking of this is in terms of feedback systems. Most biological systems seek homeostasis: if they move too far in one direction, they stabilise themselves by self-correction. This is ‘negative feedback’, the most familiar example of which is the operation of a thermostat: if the temperature constantly tends to drop, the thermostat triggers a heating system that will act to bring the temperature back to the desired level. However, systems can become unstable and enter a situation in which ‘positive feedback’ obtains – in other words, a move in one direction, rather than producing a move in the opposite direction, serves to promote further moves in the same direction, and a snowballing effect occurs. The right hemisphere, then, is capable of freeing us through negative feedback. The left hemisphere tends to positive feedback, and we can become stuck. This is not unlike the difference between the normal drinker and the addict. After a certain point, the normal drinker begins to feel less like another drink. What makes an addict is the lack of an ‘off switch’ – another drink only makes the next, and the next, more likely. And, interestingly enough, lesions of the frontolimbic systems, mainly in the right hemisphere, are associated with addictive behaviour. Pathological gamblers, for example, have frontal deficits which are mainly right-sided;484 by contrast, in cocaine addicts, for example, stimulating the right prefrontal cortex reduces craving for cocaine.485 And denial, a left-hemisphere speciality, is typical of addiction.

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