The SSC area expanded only when the monkey had to pay attention to the sensation of touch in order to receive the reward. If a monkey was trained to keep a hand on the wheel that moved just the same, but he did not have to pay attention to it… the cortical map remained the same size.
Is that a bad thing? Useful evidence would be a functional difference, achieving a lower performance level. As presented, this could just mean that training in that mode doesn’t have an easily visible expression as a localized change in brain structure.
The rest of the post makes sense as a plausible narrative (when we forget the evidence that wasn’t presented in the post), but this one point of supporting evidence (that would make the take-home message more reliable) doesn’t seem to hold as stated.
Putting aside that you do measure performance (animal behavior in response to turning frequency change), generally, yes, it is a bad thing.
We have decades of research that show that structural brain changes are required for any change in performance level. Something has to change—efficiency of synapses, number of synapses, wiring topology, number of circuits involved… but you always have a change.
In the study I chose as the example, the authors used one possible point of change, the SSC map area. Sensory acuity can be improved at several different levels along the sensory pathway, before map is reached, or in the reactive pathways that follow map activation. Indeed, one of the monkeys in this trial showed improvement in performance without statistically significant increases in the cortical area. So we know that we don’t have a perfect method of measurement here.
Which is why there are multiple subjects in this study, and two other studies cited which use different methods, measuring different brain structures and different performance aspects.
Is that a bad thing? Useful evidence would be a functional difference, achieving a lower performance level. As presented, this could just mean that training in that mode doesn’t have an easily visible expression as a localized change in brain structure.
The rest of the post makes sense as a plausible narrative (when we forget the evidence that wasn’t presented in the post), but this one point of supporting evidence (that would make the take-home message more reliable) doesn’t seem to hold as stated.
Putting aside that you do measure performance (animal behavior in response to turning frequency change), generally, yes, it is a bad thing.
We have decades of research that show that structural brain changes are required for any change in performance level. Something has to change—efficiency of synapses, number of synapses, wiring topology, number of circuits involved… but you always have a change.
In the study I chose as the example, the authors used one possible point of change, the SSC map area. Sensory acuity can be improved at several different levels along the sensory pathway, before map is reached, or in the reactive pathways that follow map activation. Indeed, one of the monkeys in this trial showed improvement in performance without statistically significant increases in the cortical area. So we know that we don’t have a perfect method of measurement here.
Which is why there are multiple subjects in this study, and two other studies cited which use different methods, measuring different brain structures and different performance aspects.