Intraindividual performance variability is associated with the complexity of the task, level of knowledge, age, and cognitive abilities of individuals. It is not known how the intraindividual variability of food-acquisition behavior is changed in trained young and adult individuals in the process of further learning.
The purpose of the study was to compare the intraindividual variability of the instrumental food-acquisition behavioral acts of young and adult rats during the training sessions.
The study was carried out on young (about 1.5 months) and adult (6-10 months) Long-Evans rats trained to press two levers in order to get food from two feeders over a period of several days. The animals were trained in stages, one behavioral act during the day. Animals underwent the surgery before they were trained to press second lever in order to process further cortex neuronal recordings during the performance of learned behavior. The analysis includes behavioral data obtained in the course of post-operative training sessions.
Intraindividual variance of the approach to the first pedal tended to decrease in adult rats (Pearson correlation coefficient r = -0.329, p = 0.066) throughout the training sessions, but increased in young animals (r = 0.568, p = 0.027). It was shown that decrease of the intraindividual variability duration indicated that the individual is trained (Antonitis, 1951, Eckerman, Lanson, 1969). Increasing of the intraindividual variability duration of approach to the pedal may indicate that games and research motivation make a significant contribution to the food-acquisition behavior in young animals, in contrast to adult.
In adult rats, indices of food-acquisition behavior on one side of the experimental cage were positively associated with the corresponding indices that were recorded on the other side of the cage during the performance of food-acquisition behavior; in young rats, these links were not found.
Thus, the duration of instrumental food-acquisition behavioral acts continues to change over practice routine sessions after the end of the training, and the nature of these changes is different in young and adult individuals.
This work was supported by grants RFH № 13-06-00461a and the Council of the President of Russia's leading scientific schools NSh-3010.2012.6.