I'll be honest, that is a pretty compelling testimonial for many folks.
[0]: http://www.lastwordonnothing.com/2012/02/09/better-living-th...
And then, finally, the main question: what role does doubt and fear play in our lives if its eradication actually causes so many improvements? Do we make more ethical decisions when we listen to our inner voices of self-doubt or when we’re freed from them? If we all wore these caps, would the world be a better place?
That's a really interesting thought. Not so much "would the world be better", as there is a presumption present in that question that more rational decision making is necessarily better, but if tDCS works similar to how it did with her with other people, we might have a way to study rational decision making in groups in interesting ways.
That is, there are assumptions involved, but I think a case could be made that emotions are a way to bypass rational thought when it's less efficient, useful (too slow for the situation) or lack of information (or lack of our own capability) causes us to fall into local maxima thinking (e.g. love, distrust of the different, etc).
If tDCS helps test this in some manner, that would also be good. We of course need a lot more information on what tDCS actually does first though. It's entirely possible that the described effects are not what is happening at all, just what it feels like. Measuring the state of the mind is weird.
Are psychopaths not a good indicator of what might happen if your self limiting emotions/thoughts were turned off?
> Are psychopaths not a good indicator of what might happen if your self limiting emotions/thoughts were turned off?
Possibly? If your goal is the ultimate advancement of the self, then sociopathic tendencies might yield the best results. We've evolved to have strong emotions regarding our offspring and those of our tribe, because that's proven a beneficial strategy for the species, but that is, in some respect, to the detriment of the individual. Most of us are fine with this decision, because of our feelings regarding our and our future offspring, but if you have no care for family, friends or the species as a whole, then gaming the system for your own advancement is probably the rational choice.
There are interesting implications to your sentence though. The blogger explained the loss of (generally perceived as) negative emotions, but what if they were not put in a situation to notice, or were unable to because of the condition itself, a loss in what we generally perceive as positive emotions, such as empathy and sympathy? This of course assumes that there was some emotional state change, and it wasn't a placebo effect.
Sounds remarkably similar to what happens as a result of various techniques of meditation - but, of course, I've no way to tell whether it's actually the same thing.