Bekhtereva N P, Medvedev S V, Krol' E M
Fiziol Zh SSSR Im I M Sechenova. 1984 Jul;70(7):892-903.
The time characteristics of the interneuronal connections as well as interrelationships among distant neuronal populations of the human brain deep structures were studied during monotonous mental activity. It was shown that stable interrelationships could be considered as a correlate of mental activity though the connections themselves were not of the correlative nature. These connections, being the elements of the activity--maintaining system, could be of various degree of rigidity.