Good question, and both your last paragraph and gregv’s answer are on the right track.
Mindfulness meditation is, above all else, training of attentional control. You choose what to focus at, and how to focus on it. Therefore, instead of focusing on “ohcrapithurtsithurtsithurts” (which would make the pain worse), someone with great deal of meditation experience can easily focus on other thoughts, or on how irrelevant the pain is (which trains the brain to make it irrelevant).
Or at least that’s the theory. Pain is a very complicated mechanism, and many caveats apply.
A side note on cortical thickness: IMHO, it is one of the most useless measures in neuroscience. Ok, fine, it can be a good preliminary note, along the lines of “this area here should be looked at in more detail,” but it doesn’t provide much more information beyond that. You can get increases in thickness due to outgrowth of the neuropil, or ingrowth of axonal inputs from the outside—and these in turn reflect an increase in excitatory or inhibitory or modulatory inputs (or some combination of the three). So in the end, you don’t really have any idea what’s really going on.
My guess is that the cortical thickening reflects an increase in the number of inhibitory synapses. The area gets larger because people get better at suppressing the activity within it.
This can also serve as an illustration of one limit (among many) of fMRI in general. fMRI (in most cases) measures blood flow/oxygenation increases in an area, which is related to neural activity. Neurons fire, they need energy, signals go out to increase blood supply. Area “lights up” on the scanner.
However, what kind of activity are you talking about? Activity of excitatory neurons, which activate an area, requires energy and oxygen, hence blood flow, hence it “lights up.” Activity of inhibitory neurons, acting to shut down or attenuate the actual functional activity of an area, also requires energy, which requires increases in blood flow, which makes the area “light up.” A bright spot therefore can mean “this area is somehow involved in the process I’m looking at,” but it doesn’t tell you if it needs to be activated or deactivated for the function to proceed. As you can imagine, this severely limits interpretation.
Good question, and both your last paragraph and gregv’s answer are on the right track.
Mindfulness meditation is, above all else, training of attentional control. You choose what to focus at, and how to focus on it. Therefore, instead of focusing on “ohcrapithurtsithurtsithurts” (which would make the pain worse), someone with great deal of meditation experience can easily focus on other thoughts, or on how irrelevant the pain is (which trains the brain to make it irrelevant).
Or at least that’s the theory. Pain is a very complicated mechanism, and many caveats apply.
A side note on cortical thickness: IMHO, it is one of the most useless measures in neuroscience. Ok, fine, it can be a good preliminary note, along the lines of “this area here should be looked at in more detail,” but it doesn’t provide much more information beyond that. You can get increases in thickness due to outgrowth of the neuropil, or ingrowth of axonal inputs from the outside—and these in turn reflect an increase in excitatory or inhibitory or modulatory inputs (or some combination of the three). So in the end, you don’t really have any idea what’s really going on.
My guess is that the cortical thickening reflects an increase in the number of inhibitory synapses. The area gets larger because people get better at suppressing the activity within it.
This can also serve as an illustration of one limit (among many) of fMRI in general. fMRI (in most cases) measures blood flow/oxygenation increases in an area, which is related to neural activity. Neurons fire, they need energy, signals go out to increase blood supply. Area “lights up” on the scanner.
However, what kind of activity are you talking about? Activity of excitatory neurons, which activate an area, requires energy and oxygen, hence blood flow, hence it “lights up.” Activity of inhibitory neurons, acting to shut down or attenuate the actual functional activity of an area, also requires energy, which requires increases in blood flow, which makes the area “light up.” A bright spot therefore can mean “this area is somehow involved in the process I’m looking at,” but it doesn’t tell you if it needs to be activated or deactivated for the function to proceed. As you can imagine, this severely limits interpretation.