[Capacity for learning and extrapolation of mice selected for having different brain weights].

Ability for learning a simple food-searching reaction, and for extrapolation of a food stimulus movement has been studied in two lines of laboratory mice selected throughout 15 generations for high (H-line) and low (L-line) brain weight. It has been found that the mice from H-line learn the food-searching reaction more rapidly than those from L-line. In first presentation of the extrapolation task, the percentage of right solvings by mice from H- and L-lines does not differ from the 50%, expected for the random alternative choice. In subsequent presentations, the percentage of right solvings steadily increases in both lines, and taken over all presentations significantly exceeds the 50% random level, while the mean time of performance gradually grows shorter. Thus, no difference is observed between H- and L-lines either in solving the extrapolation task or in learning this practice, in contrast to a noticeable superiority of H-line in learning a simple motor reaction.